Planet TripleO


August 07, 2018

Cedric Jeanneret

Accessing private stuff from your build server

While working on the validations/tests for the new release, I had the need to access specific packages and repositories behind a VPN.

Some corporate VPN don’t allow to have multiple connection for the same user (confession: I didn’t test it ;)), meaning your home build server can’t access the private resources while your workstation is connected.

There are two ways: either build some gateway on your own, put your corporate VPN on it, and put your work machines behind. That can be a pain, especially since VPN eats a lot of resources, and in some cases, you will need to access the gateway and update the password everytime you reboot it.

The other one is kind of more funny: just use squid.

The setup is really easy:

  • setup squid on your workstation
  • allow only your LAN to access this service
  • allow port 3128/tcp
  • configure your buildserver VMs to use that proxy

In TripleO environment, this means mainly: configure the undercloud to use your squid as a proxy for Yum and Docker.

In order to do that, you need to push a simple line in /etc/yum.conf:

proxy = http://<PROXY_HOST>:3128

PROXY_HOST being your workstation IP address. In addition, you will need to push a configuration file for docker. The easiest way is to push something in systemd directly.

If you create a /etc/systemd/system/docker.service.d/http-proxy.conf file with the following content, you should be fine:


In case you do that after docker has been deployed, you will need to reload the systemd daemon and restart docker:

systemctl daemon-reload
systemctl restart docker

Once this is done, you will be able to access the private things behind the corporate VPN without the need of running the VPN on you build machine.

This also is more secure, especially if you ensure the squid port is locked by default, and open it only when you actually NEED it.

On my own, I just run the following command in order to open it on the workstation:

firewall-cmd --zone public --add-port 3128/tcp

Note: there isn’t the “–permanent” option, meaning next reboot or firewall reload will drop the rule. In addition, ensuring your squid.conf only allows your LAN to connect is a good thing.

In addition, my squid.conf also ignore repodata files in order to avoid bad caching:

acl repodata url_regex .*repodata.*
cache deny repodata

As a final note: squid is a powerful tool, not only for caching. In fact, if you must access TLS encrypted URI, squid won’t cache anything (by default it doesn’t do TLS-MitM), but at least it will allow to access remote, protected contents in an easy way.

The fact it doesn’t cache TLS URI will prevent most of the caching, especially the containers layers - this is a good thing in order to prevent disk usage issues on your computer ;).

August 07, 2018 11:00 AM

July 24, 2018

Carlos Camacho

Vote for the OpenStack Berlin Summit presentations!

¡¡¡Please vote!!!

I pushed some presentations for this year OpenStack summit in Berlin, the presentations are related to updates, upgrades, backups, failures and restores.

Happy TripleOing!

by Carlos Camacho at July 24, 2018 12:00 AM

July 06, 2018

Cedric Jeanneret

New spec for TripleO: integrate oslo.privsep in tripleoclient

Security is an important thing. Especially nowadays, when you can read, hear tons of companies and entities getting hacked in funny ways.

Currently, the TripleO project has some issues with too widely opened sudo rules. They allow standard users to basically own the whole node without any password.

Of course, you’ll still need an access (remote or local) to the node in order to profit from the sudo. But it might be triggered without a shell, if some service using one of those power users have a flaw.

This can’t stay as is, and should be corrected, of course. Security is also important in Open Source projects, especially an attack surface as big as OpenStack.

In order to correct that bad situation, two specifications are currently under review, and are to be implemented in Stein release (due for next year).

The first one aims python scripts. Currently, at least in python-tripleoclient, there are wild calls to sudo in order to call itself. This is one example among others, and it’s pretty ugly.

This kind of calls also creates some issue with the rights of generated files, and leads to other sudo calls we don’t want to see.

The solution isn’t easy though. In order to prevent any NOPASSWD:ALL in the sudoers, we’ll need to refactor the code, and introduce oslo.privsep, a python library aiming a secure and clear privilege escalation, with proper filters and the like.

Basically, in the tripleoclient case, we will need to replace all the os.chown calls by plain rootwrap subprocess calls. The os.chown isn’t the only one, there are most probably other things that will need to be corrected and correctly isolated. And as some services are launched as another user during the deploy process, we will also need to take those kind of calls out, and push them in a separated script, called with the rootwrap instead.

The advantages of using oslo.privsep are multiple:

  • generic library embedded in oslo, meaning good code convergence
  • better filtering than plain sudo
  • good isolation
  • clean separation of the application code and the privilege escalation
  • young project, meaning we can build best practices based on real experience

The second proposal aims plain sudo calls from shell script and ansible. It will not require any code refactoring, but more a log review in order to catch all the reall sudo needs, and list them in the sudoers.d/user file.

There again, the goal is to prevent any unwanted privilege escalation via passwordless sudo calls.

In the end, when both those proposals are accepted and implemented, we will end up with a more secure TripleO deployment, more secure nodes, and less issues with people refusing to deploy OpenStack due to those bad sudo practices.

So, if you’re interested in Security and OpenStack, you definitively will review those two proposals and take part in this revolution.

July 06, 2018 08:30 AM

June 07, 2018

Ben Nemec

Vancouver Summit - Deja Vu Edition

This was the first repeat OpenStack Summit location for me. While there have been repeat locations in the past, I wasn't at the first Summit at any of those locations. I think that means I'm getting old. :-)

There was a lot that had changed, and also a lot that stayed the same. The Vancouver Convention Center is still a fantastic venue, with plenty of space for sessions. And although I did attend all of the Oslo sessions, just like last time, we didn't over-schedule Oslo this time so I had a chance to attend some non-Oslo sessions as well. Since I'm also focusing on Designate these days, I made sure to catch all of those sessions, even the one at 5:30 PM on Thursday when everyone was a bit tired and ready to leave. And it was good - there was useful information in that presentation. I felt more productive at this Summit than last time, which is certainly a good thing.

With the intro out of the way, let's get down to the nuts and bolts of the sessions I attended.

Default Roles

This is a thing that many operators have been asking to have for quite a while. Unfortunately, early attempts were problematic because the state of policy in OpenStack was not good. Fortunately, since then most (if not all) projects have adopted oslo.policy which allows proper deprecation of policy rules so we can actually fix some of the issues. Currently there are three proposed default roles: auditor (aka read-only), member, and admin. While two of those already exist, apparently there are many bugs around how they work which should be cleaned up as part of this work, resulting in three actually usable roles. This will eventually be tested via the Patrole project, but there's no point in writing tests now for broken behavior so the testing will happen in parallel with the implementation.

Chances are that the default roles won't satisfy everyone, but the hope is that they can address the needs of the majority of operators (I think 80% was mentioned as a target) to reduce the pain of configuring a production OpenStack deployment. I know there were a few operators in the room who didn't feel the proposed roles would help them, and there was some post-session discussion that hopefully surfaced their concerns to the Keystone team who are driving this work.

Storyboard Migration

This is something that has been gaining momentum lately, with some larger teams either migrated or in the process of migrating to Storyboard. It was of particular interest to me as the Oslo PTL because I expect Oslo to be a fairly painful migration due to the sheer number of different Launchpad projects under the Oslo umbrella. However, it sounds like the migration process is becoming more mature as more projects make the move so by the time Oslo does migrate I have hope that it will go smoothly.

One significant request that came out of the session was some sort of redirect system that could point people who click on a bug reference in Gerrit to the appropriate location for projects that have migrated. I believe there was a suggestion that a separate server could be set up that had knowledge of which projects tracked bugs where and then could respond with appropriate redirects. Someone obviously would have to find the time to set that up though.

Migration to stestr

The current PTI for unit tests says to use stestr as the test runner. However, quite a few projects have not yet migrated, and this session was essentially to discuss why and how to move forward. One of the big "why"s was that people didn't know about it. A message was sent to openstack-dev, but I'm not sure it was clear to everyone that there was action required. Also, since most projects are still working, there's a natural "if it ain't broke, don't fix it" attitude toward this. Most of the projects that had been migrated were done by mtreinish, who has been driving this initiative.

Moving forward, there will be more of an emphasis on the benefits of moving to stestr and some work to provide a guide for how to do so. That should help get everyone into a consistent place on this.

Ops/Dev: One Community

Generally speaking, everyone recognizes that there needs to be a tighter feedback loop between developers and operators so that the people running OpenStack are getting the features and bugfixes they really need. In the past this hasn't always been the case, but things like co-locating the PTG and Ops meetup are intended to help. This was a discussion of how to further improve that relationship.

There was a point raised that developer events in the past had been perceived as (and perhaps were) hostile to operators on older releases. The good news is that this attitude seems to have softened considerably in the past few cycles, with initiatives like fast-forward upgrades and extended maintenance releases acknowledging that in the real world not everyone can do continuous deployment and always be on the latest bleeding edge code.

A lot of the discussion around future changes to improve this had to do with the current split in mailing lists. Creating a separation between users, operators, and developers of OpenStack is obviously not ideal. The main suggestion was to move to a more traditional -discuss and -announce split, with the latter being a low-traffic list just used for major announcements. There was some concern that even though the development mailing list is not quite as active as it was at its peak, there is still an order of magnitude more traffic there than on the other lists and it might become overwhelming if everyone just got dumped into it. Related to this, there was some discussion of moving to mailman3, which provides a forum-like interface to allow casual contributors to join discussions without subscribing to the full firehose of mailing list traffic. There were a few technical concerns with it, but overall it seemed promising.

Also out of this session came a side topic about part-time contributors and what to do in this new OpenStack world where many of the contributors to projects can't devote 100% of their time to a project. As there wasn't time in the session to cover this adequately, a separate hallway track discussion was scheduled, which I will cover later.

Python 2 Deprecation Timeline

Python 2 is going away. Currently OpenStack still runs primarily on Python 2, which means we have some work to do before early 2020 when upstream support for it ends. The first step will be to re-orient our testing to focus on Python 3. In the past, jobs ran on Python 2 by default and Python 3 jobs were the outliers. That has to change.

The current timeline is to have Python 3 tested as the primary target by the end of the Stein cycle, and then to have Python 3 in a state where it can become the only supported Python version by the end of the T cycle, so that Python 2 support can be dropped early in the U cycle. Assuming we hit these targets, they line up well with the upstream Python plans.

oslo.config drivers hack session

On Tuesday we held an unofficial Oslo hack session to work through some things on the oslo.config driver patches that are in progress. They are intended to add new functionality to oslo.config which will enable features such as storing config in a key-value store like etcd and moving secret data (passwords, tokens, etc.) to a more secure service accessible via Castellan. The details are documented in the link above, but overall I think we made good progress on the plan and identified some concrete actions needed to move the work forward.

Oslo Project Onboarding

This was the first time we've done an Oslo onboarding session, and all things considered I would say it went reasonably well. There was some digression in the discussion, which is understandable in a project as wide-ranging as Oslo. There was also some interest in getting involved though, so I think it was a worthwhile session. Most importantly, it wasn't me talking to an empty room for 40 minutes. :-)

Designate Project Update

For the most part I just recommend you go watch the video of Graham's presentation. He'll do a better job explaining Designate stuff than I can. However, one thing that was sort of specific to me from this session was that I met a couple of Designate deployers who had written Ansible playbooks to deploy it in a TripleO overcloud post-deployment. Obviously for full integration we want it done as part of the main deployment, but their work could definitely come in handy as we move to use more Ansible in TripleO.

OpenStack Messaging at the Edge

This was a followup to a presentation at the Dublin PTG that was exploring the use of different messaging technologies in Edge deployments. It isn't testing full OpenStack edge deployments, but it did simulate the messaging architecture you'd see in such a deployment. The biggest takeaway was that distributed messaging technology like Qpid Data Router can significantly improve performance in a widely distributed system versus a broker-based system like RabbitMQ.

Oslo Project Update

I don't have too much to say about this beyond what is already in the video linked from the session page. I do really need to stop saying "umm" so much when I speak though. ;-)

Mountain Biking Stanley Park

Okay, this wasn't OpenStack-related, but if you're into mountain biking then you know BC is a great place to do it, so it was hard to resist getting in a little time on the dirt when it was walking distance from the conference. I managed to escape with only minor scrapes and bruises after my long lunch ride.

Encouraging Part-time Contributors Hallway Track

As I mentioned earlier, this came up in one of the dev/ops sessions as a pain point. I had the opportunity to sit down with Julia Kreger, Tim Bell, and Thierry Carrez to try to identify some ways we could make it easier for new or occasional contributors to work on OpenStack. This is particularly important in the academic world where research contracts are often for a very specific, fixed period of time. If changes don't make it in during that window, they will tend to be abandoned.

A number of ideas were suggested, and ultimately we decided to focus on what we hoped would be the least controversial option to avoid the boil-the-ocean problem of attacking everything at once. To that end, we decided to propose a new policy targeted at reducing the amount of nit-picking in the review process. -1's over typos in code comments or the use of passive voice in specs do not meaningfully contribute to the quality of OpenStack software, but they can be disproportionately demotivating to both new and experienced developers alike. I know I personally have changed my reviewing style in a big way as a result of my own frustration with being on the receiving end of nit-pick reviews (deepest apologies to everyone I have nit-picked in the past).

This proposal led to a rather long mailing list thread, which I think demonstrates why we decided to stick with one relatively simple change in the beginning. As it was, the discussion tangented into some of the other areas we would like to address eventually but didn't want to get bogged down with right now.

Overall, I have high hopes that this initiative will make OpenStack a more pleasant project to work on while not meaningfully harming the quality of the software.

API Debt Cleanup

I must confess I'm not sure I fully understand the proposed way forward here. It seemed to me that there are two conflicting goals here: 1) To not break existing users of OpenStack APIs and 2) To make it easier for users to consume new functionality added in more recent microversions of OpenStack APIs. The concern seemed to be that many users are not aware of or not able to use new microversions so they are missing out on functionality and improved API designs. However, if we raise the default microversion then we open up the possibility of breaking existing users because new microversions may not be 100% compatible with old ones. As long as microversions are opt-in that's fine, but once you start changing the minimum microversion it becomes a problem.

The proposal was sort of a "big bang" major version bump across OpenStack. Essentially we would pick a cycle and have all of the projects do their desired API cleanup and everyone would tag a new major version of their API at about the same time. I'm still not entirely clear how this solves the problem I mentioned above though. A new default major version still opens up the possibility of breaking users that rely on older behavior, and a new major version that isn't the default still requires users to opt in. Maybe it's just that opting in to a new major version is easier than a new microversion?

I'm hoping that I missed some fundamental key to how this works, or maybe just missed that some of these tradeoffs are considered acceptable. In any case, it will be interesting to see how this work progresses.

OpenStack Maintainers

This ended up being another session that focused heavily on how to keep the OpenStack community healthy. The proposal was that there should be a group of people who are solely concerned with maintaining and cleaning up the code. This group would not be involved in new feature work.

Obviously this is a hard sell, as most developers want to do feature work. In addition, if you're not actively working on the code it's harder to stay up to date on where the project is going so you can provide useful architectural reviews. Overall, I did not feel like the idea of dedicated maintainers gained much traction in the room, but there was a lot of good discussion of how to encourage maintenance-type activities from existing and new contributors. The details can be found on the etherpad.

Stein Release Goals

In the Stein Release Goal session...we identified a whole bunch of goals for the T release. Okay, not entirely true, but there were a number of ideas floated that got nacked because they wouldn't be ready for Stein, but might be for T. I'm not going to try to cover them all here, but you can read more on the etherpad.

The other thing that happened in this session was we got rather side-tracked on the topic of how to select goals and what makes a good goal. The point was made that it's good to have community goals with a "wow" factor. These help the marketing teams and attract people to OpenStack, a good thing for everyone. However, the question was raised as to why we aren't selecting only "wow" goals that immediately address operator needs. It's a valid question, but it's not as simple as it appears on the surface.

See, all of the goals ultimately benefit operators. But the strategy so far with community goals has been to select one directly operator-facing goal, and one indirect goal. The latter is often related to cleaning up tech debt in OpenStack. While that may not have the same kind of immediate impact that something like mutable config does, it can have a huge long-term impact on the health and velocity of the project. Sure, splitting out the Tempest plugins for projects didn't have a direct impact on operators in that cycle, but it freed up bandwidth for everyone to be able to land new features faster. We paid down the debt in the short term to enable larger long term gains.

All of which is basically me saying that I like the idea behind our goal selection up to this point. I think one of each is a good balance of both immediate and longer-term impact.

In this session there was also some post-mortem of the previous goals. The WSGI API deployment goal was pointed out as one that did not go so well. Halfway through the cycle there was a massive shift in direction for that goal which caused bunch of re-work and bad feelings about it. As a result, there were some recommendations for criteria that goals need to meet going forward to avoid selection of goals that aren't quite fully-baked yet. You can also read more about those on the etherpad.

Unified Limits

I mostly attended this because it involves the new oslo.limit library so I thought I should have some idea of what was going on. I'm really glad I did though because it turned out to be an excellent deep dive into how the unified limits API is going to work and how it could address the needs of some of the operators in the room. I came out of the session feeling very good about where quota management in OpenStack is headed.

Designate Best Practices

The very last session slot of the Summit, and as a result there wasn't a ton of audience participation (although there were still a fair number of people in attendance). However, there was quite a bit of useful information presented so I recommend watching the video if you are interested in operating Designate.

I skipped writing a summary for a few of the sessions that I attended, either because I thought they would be covered elsewhere or because they were simply too much to discuss in this already too-long post. I hope what I wrote above was interesting and maybe even a little helpful though.

by bnemec at June 07, 2018 08:34 PM

June 04, 2018

Steven Hardy

TripleO Containerized deployments, debugging basics

Containerized deployments, debugging basics

Since the Pike release, TripleO has supported deployments with OpenStack services running in containers.  Currently we use docker to run images based on those maintained by the Kolla project.

We already have some tips and tricks for container deployment debugging in tripleo-docs, but below are some more notes on my typical debug workflows.

Config generation debugging overview

In the TripleO container architecture, we still use Puppet to generate configuration files and do some bootstrapping, but it is run (inside a container) via a script

The config generation usage happens at the start of the deployment (step 1) and the configuration files are generated for all services (regardless of which step they are started in).

The input file used is /var/lib/docker-puppet/docker-puppet.json, but you can also filter this (e.g via cut/paste or jq as shown below) to enable debugging for specific services - this is helpful when you need to iterate on debugging a config generation issue for just one service.

[root@overcloud-controller-0 docker-puppet]# jq '[.[]|select(.config_volume | contains("heat"))]' /var/lib/docker-puppet/docker-puppet.json | tee /tmp/heat_docker_puppet.json
"puppet_tags": "heat_config,file,concat,file_line",
"config_volume": "heat_api",
"step_config": "include ::tripleo::profile::base::heat::api\n",
"config_image": ""
"puppet_tags": "heat_config,file,concat,file_line",
"config_volume": "heat_api_cfn",
"step_config": "include ::tripleo::profile::base::heat::api_cfn\n",
"config_image": ""
"puppet_tags": "heat_config,file,concat,file_line",
"config_volume": "heat",
"step_config": "include ::tripleo::profile::base::heat::engine\n\ninclude ::tripleo::profile::base::database::mysql::client",
"config_image": ""


Then we can run the config generation, if necessary changing the tags (or puppet modules, which are consumed from the host filesystem e.g /etc/puppet/modules) until the desired output is achieved:

[root@overcloud-controller-0 docker-puppet]# export NET_HOST='true'
[root@overcloud-controller-0 docker-puppet]# export DEBUG='true'
[root@overcloud-controller-0 docker-puppet]# export PROCESS_COUNT=1
[root@overcloud-controller-0 docker-puppet]# export CONFIG=/tmp/heat_docker_puppet.json
[root@overcloud-controller-0 docker-puppet]# python /var/lib/docker-puppet/docker-puppet.py2018-02-09 16:13:16,978 INFO: 102305 -- Running docker-puppet
2018-02-09 16:13:16,978 DEBUG: 102305 -- CONFIG: /tmp/heat_docker_puppet.json
2018-02-09 16:13:16,978 DEBUG: 102305 -- config_volume heat_api
2018-02-09 16:13:16,978 DEBUG: 102305 -- puppet_tags heat_config,file,concat,file_line
2018-02-09 16:13:16,978 DEBUG: 102305 -- manifest include ::tripleo::profile::base::heat::api
2018-02-09 16:13:16,978 DEBUG: 102305 -- config_image


When the config generation is completed, configuration files are written out to /var/lib/config-data/heat.

We then compare timestamps against the /var/lib/config-data/heat/heat.*origin_of_time file (touched for each service before we run the config-generating containers), so that only those files modified or created by puppet are copied to /var/lib/config-data/puppet-generated/heat.

Note that we also calculate a checksum for each service (see /var/lib/config-data/puppet-generated/*.md5sum), which means we can detect when the configuration changes - when this happens we need paunch to restart the containers, even though the image did not change.

This checksum is added to the /var/lib/tripleo-config/hashed-docker-container-startup-config-step_*.json files by, and these files are later used by paunch to decide if a container should be restarted (see below).


Runtime debugging, paunch 101

Paunch is a tool that orchestrates launching containers for each step, and performing any bootstrapping tasks not handled via

It accepts a json format, which are the /var/lib/tripleo-config/docker-container-startup-config-step_*.json files that are created based on the enabled services (the content is directly derived from the service templates in tripleo-heat-templates)

These json files are then modified via (as mentioned above) to add a TRIPLEO_CONFIG_HASH value to the container environment - these modified files are written with a different name, see /var/lib/tripleo-config/hashed-docker-container-startup-config-step_*.json

Note this environment variable isn't used by the container directly, it is used as a salt to trigger restarting containers when the configuration files in the mounted config volumes have changed.

As in the docker-puppet case it's possible to filter the json file with jq and debug e.g mounted volumes or other configuration changes directly.

It's also possible to test configuration changes by manually modifying /var/lib/config-data/puppet-generated/ then either restarting the container via docker restart, or by modifying TRIPLEO_CONFIG_HASH then re-running paunch.

Note paunch will kill any containers tagged for a particular step e.g the --config-id tripleo_step4 --managed-by tripleo-Controller means all containers started during this step for any previous paunch apply will be killed if they are removed from your json during testing.  This is a feature which enables changes to the enabled services on update to your overcloud but it's worth bearing in mind when testing as described here.

[root@overcloud-controller-0]# cd /var/lib/tripleo-config/
[root@overcloud-controller-0 tripleo-config]# jq '{"heat_engine": .heat_engine}' hashed-docker-container-startup-config-step_4.json | tee /tmp/heat_startup_config.json
"heat_engine": {
"healthcheck": {
"test": "/openstack/healthcheck"
"image": "",
"environment": [
"volumes": [
"net": "host",
"privileged": false,
"restart": "always"
[root@overcloud-controller-0 tripleo-config]# paunch --debug apply --file /tmp/heat_startup_config.json --config-id tripleo_step4 --managed-by tripleo-Controller
stdout: dd60546daddd06753da445fd973e52411d0a9031c8758f4bebc6e094823a8b45

[root@overcloud-controller-0 tripleo-config]# docker ps | grep heat
dd60546daddd "kolla_start" 9 seconds ago Up 9 seconds (health: starting) heat_engine



Containerized services, logging

There are a couple of ways to access the container logs:

  • On the host filesystem, the container logs are persisted under /var/log/containers/<service>
  • docker logs <container id or name>
It is also often useful to use docker inspect <container id or name> to verify the container configuration, e.g the image in use and the mounted volumes etc.


Debugging containers directly

Sometimes logs are not enough to debug problems, and in this case you must interact with the container directly to diagnose the issue.

When a container is not restarting, you can attach a shell to the running container via docker exec:

[root@openstack-controller-0 ~]# docker exec -ti heat_engine /bin/bash
()[heat@openstack-controller-0 /]$ ps ax
1 ? Ss 0:00 /usr/local/bin/dumb-init /bin/bash /usr/local/bin/kolla_start
5 ? Ss 1:50 /usr/bin/python /usr/bin/heat-engine --config-file /usr/share/heat/heat-dist.conf --config-file /etc/heat/heat
25 ? S 3:05 /usr/bin/python /usr/bin/heat-engine --config-file /usr/share/heat/heat-dist.conf --config-file /etc/heat/heat
26 ? S 3:06 /usr/bin/python /usr/bin/heat-engine --config-file /usr/share/heat/heat-dist.conf --config-file /etc/heat/heat
27 ? S 3:06 /usr/bin/python /usr/bin/heat-engine --config-file /usr/share/heat/heat-dist.conf --config-file /etc/heat/heat
28 ? S 3:05 /usr/bin/python /usr/bin/heat-engine --config-file /usr/share/heat/heat-dist.conf --config-file /etc/heat/heat
2936 ? Ss 0:00 /bin/bash
2946 ? R+ 0:00 ps ax


That's all for today, for more information please refer to tripleo-docs,, or feel free to ask questions in #tripleo on Freenode!

by Steve Hardy ( at June 04, 2018 05:09 PM

June 01, 2018

James Slagle

TripleO and Ansible: config-download with Ansible Tower (part 3)

In my 2 previous posts, I’ve talked about TripleO’s config-download. If you
haven’t had a chance to read those yet, I suggest checking them out here and

One of the nice things about config-download is that it integrates nicely with
other Ansible based tooling. In particular, Ansible Tower (or Ansible AWX) can
be used to drive applying the overcloud configuration. For users and
operators who are already familiar with Tower, this provides a nice way to
manage and report on the overcloud deployment status with TripleO and Tower.

At a high level, this integration is broken down into the following steps on
the TripleO undercloud:

  1. Create the Heat stack
  2. Run openstack overcloud config download to download the ansible
    playbooks from Heat
  3. Run tripleo-ansible-inventory to create the Ansible inventory file
  4. Since Ansible Tower uses git or other (SCM’s) to synchronize and manage
    Ansible project directories, we create a git repo from the config-download
    directory on the undercloud.

Switching over to Ansible Tower, we then:

  1. Create an organization
  2. Create SCM (git) credentials and machine credentials
  3. Create the Ansible project, pointing it at the git repository we created on
    the undercloud
  4. Create the inventory and inventory source, pointing it at the inventory file
    within the project directory we created with tripleo-ansible-inventory.
  5. Create a Job Template to run deploy_steps_playbook.yaml from the project
  6. Launch the Job Template

When the job finishes, we have a deployed and configured overcloud ready for
use by tenants.

Here’s a video of the demo showing the above steps:

Of course, we wouldn’t want to manually go through those steps every time. We
can instead automate them with an ansible playbook, and then execute the
playbook from the undercloud, or a different management node. An example
playbook that automates all the steps above can be seen here:

by James Slagle at June 01, 2018 09:51 PM

May 31, 2018

Juan Antonio Osorio

Setting up Keberos for Keystone auth with mod_auth_gssapi

Setting up Keberos for Keystone auth with mod_auth_gssapi

I’ve been following blog posts about setting up Keystone with kerberos authentication, and recently tried to implement that manually in TripleO. Here’s how it went:

mod_auth_gssapi instead of mod_auth_kerb

Asking around, it turns out that mod_auth_kerb is not going to be supported anymore, and using mod_auth_gssapi is the preferred alternative. Unfortunately all the blogs I found were using mod_auth_kerb, so I needed to research how to use mod_auth_gssapi.

Required packages

We’ll need to install the following packages in the host where keystone is running:

  • mod_auth_gssapi
  • python-requests-kerberos

Given that we run keystone in a container in TripleO, I needed to add those packages to the keystone container.


I deployed TripleO with TLS everywhere to have all the nodes enrolled to FreeIPA and set up keystone to use LDAP-backed domains as I referenced in a previous blog post.

This would leave me with a deployment where I can authenticate to keystone using users coming from FreeIPA’s LDAP.

Given that we deployed using TLS everywhere, we already have quite a bunch of service principals registered in FreeIPA, namely, we already have HTTP/overcloud-controller-<number>.<networks>.<domain>. Unfortunately, this is not a principal we can use, since the clients will authenticate to keystone by first going through HAProxy, which is listening on the external network and has the FQDN that references the ‘cloud name’. Lets say that our domain is In that case, we’ll need to have a principal that looks as follows: HTTP/ (assuming our kerberos realm matches the domain).

So, lets add this principal to FreeIPA:

ipa service-add HTTP/ --force

Subsequently, we’ll need to tell FreeIPA that the service is being managed by another host (given that there actually isn’t a host for Assuming we only have one controller named, we can make it manage the service with the following command:

ipa service-add-host HTTP/

Having done this in the FreeIPA server, we can now go to our controller(s) and get the necessary kerberos keytab for that service:

# We get the host's credentials
kinit -kt /etc/krb5.keytab

# Using those credentials we request the keytab
ipa-getkeytab -p HTTP/ -k /var/lib/config-data/puppet-generated/keystone/etc/keystone.keytab

# We change the permissions so httpd has access to the keytab
chown root:apache /var/lib/config-data/puppet-generated/keystone/etc/keystone.keytab
chmod 0660 /var/lib/config-data/puppet-generated/keystone/etc/keystone.keytab

We’ll notice that I used /var/lib/config-data/puppet-generated/keystone/ as a path. This is because we’re using a containerized deployment in TripleO, and this is the directory that’s bind-mounted to the keystone container.

I also changed the file permissions of the keytab, so the apache process can access it.


With all the previous steps done, we can start configuring keystone’s apache instance!

To avoid issues in the container, I manually copied 10-auth_gssapi.conf to the container’s conf.modules.d directory. We can do this from the host by getting that file as 10-auth_gssapi.load into /var/lib/config-data/puppet-generated/keystone/etc/httpd/conf.modules.d.

Subsequently, I added the following configuration to keystone’s apache configuration in the conf.d directory:

  WSGIScriptAlias /krb "/var/www/cgi-bin/keystone/keystone-public"
  WSGIScriptAlias / "/var/www/cgi-bin/keystone/keystone-public"
  WSGIPassAuthorization On

  <Location "/krb/v3/auth/tokens">
        LogLevel debug
        AuthType GSSAPI
        AuthName "GSSAPI Login"
        GssapiCredStore keytab:/etc/keystone.keytab
        GssapiCredStore ccache:FILE:/var/run/keystone-krb5ccache
        GssapiLocalName On
        Require valid-user
        SetEnv REMOTE_DOMAIN freeipadomain

We’ll be able to modify this file from the host by editing /var/lib/config-data/puppet-generated/keystone/etc/httpd/conf.d/10-keystone_wsgi_main.conf. Something similar will need to be done for the admin endpoint, which is in the same directory as 10-keystone_wsgi_admin.conf.

We’ll note that the WSGIScriptAlias / ... and WSGIPassAuthorization On already existed in the configuration.

It is also very relevant that the /krb route is added before the / route; else we’ll get 404 errors in our deployment.

Finally, I changed the methods configuration option that’s under the auth group in keystone.conf:

methods = external,password,token,kerberos,application_credential

With this, we can now restart the keystone container:

docker restart keystone


Note that we’ll need the package python-requests-kerberos in the client side as well.

To test this out, I created a user called ‘demo’ and a project called ‘freeipa-project’ in the LDAP-backed domain called ‘freeoipadomain’.

We need to authenticate to kerberos using the desired principal:

kinit demo

We’ll also need an rc file. For this example, it’ll look as follows:

# Clear any old environment that may conflict.
for key in $( set | awk '{FS="="}  /^OS_/ {print $1}' ); do unset $key ; done
export OS_NO_CACHE=True
export no_proxy=,,
export OS_CLOUDNAME=overcloud
export OS_AUTH_URL=
export NOVA_VERSION=1.1
export OS_PROJECT_DOMAIN_NAME=freeipadomain
export OS_PROJECT_NAME=freeipa-project
export OS_AUTH_TYPE=v3kerberos

Lets try it out!

openstack token issue --max-width 100
| Field      | Value                                                                               |
| expires    | 2018-05-31T16:02:37+0000                                                            |
| id         | gAAAAABbEA6NijwIrXbNndVrUjgAuz0MQoBLjpeKJ_K-                                        |
|            | OmU_ofYTxUlFISnX70fyWY5h99fsb50l6X5gsSCPXMLmDikzjfN4FDY-                            |
|            | bJ0LgO9PUc1ysYIbhKBRTIkkK2fbzPsrkBRbM8i-wy9vT2NP1ZFdVtYlWkYAwHE5hNY4Nf3HgaMoxj4t_IM |
|            | Fcjk_K6RHAcMXrkxuAS3yhd_NfJd5FnxmqwObNX42jx0eHaIbb5G3GQBDOkLSu2g                    |
| project_id | 39e72472bc964ebfb2faeaca1f865c0e                                                    |
| user_id    | ce2f93c933ca64e3e1d313942c0f5cd2e2c31ce8ffcaf92c83a7e4fac8c5afad                    |


Rob Crittenden sat down with me (virtually) to try to get this working. Thanks dude!

Blogs I used as references

May 31, 2018 01:13 PM

Carlos Camacho

TripleO deep dive session #13 (Containerized Undercloud)

This is the 13th release of the TripleO “Deep Dive” sessions

Thanks to Dan Prince & Emilien Macchi for this deep dive session about the next step of the TripleO’s Undercloud evolution.

In this session, they will explain in detail the movement re-architecting the Undercloud to move towards containers in order to reuse the containerized Overcloud ecosystem.

You can access the presentation or the Etherpad notes.

So please, check the full session content on the TripleO YouTube channel.

Please check the sessions index to have access to all available content.

by Carlos Camacho at May 31, 2018 12:00 AM

May 07, 2018

Juan Antonio Osorio

Kubecon Copenhagen 2018

Kubecon/CloudNativeCon Europe CPH from an OpenStack/TripleO point of view

I recently had the opportunity to attend Kubecon/CloudNativeCon Europe in Copenhagen. Although the event was very Kubernetes oriented, I chose to focus on the general security bits of the conference, as well as the service-mesh related topics. This was with the following reasoning:

  • Given that we’re aiming to containerize as much as we can from OpenStack, we really need to catch up and take more container security practices into use.

  • A lot of problems that we’re tackling on OpenStack are also being tackled in the kubernetes/cloud native community. We should try to converge whenever possible instead of trying to brew our own solutions.

  • The service mesh use-cases resonate very well with a lot of the security user-stories that we’ve been working on lately.

With this in mind, what I gathered from the different projects.

Service mesh

Lately I’ve been quite interested in the service-mesh topic since it’s brought up by folks tackling the same issues we’ve been facing lately in OpenStack & TripleO.


The concept of a “service mesh” is the concept of offloading all the network interaction from the service itself to a layer that sits somewhere in the host. This layer usually takes the form of a proxy. It can be in the form of a side-car container that runs with the application (so you’ll have a proxy per-service), or it can run as a singleton in the host and catch all traffic that goes towards the applications. The proxy will then be aware of all the applications that are part of the “mesh”, and handle load-balancing, service discovery, monitoring, policy, circuit breaking and it can even be your TLS proxy for the service(s).

One important concept to understand is the separation between the control plane and the data plane. The control plane is how you configure the mesh itself (probably in the form of a service that has an API or a set of APIs for this purpose), and a data plane, which is handled by the proxy, and it’s where all your application traffic flows. So, with this in mind, there are some mesh solutions that will already have a control plane implemented, whereas for other solutions, you have to brew your own.

For more info on the service mesh, I recommend these blog posts:

Tying it up with OpenStack/TripleO

One of the features we did recently was enabling TLS everywhere for TripleO, and if I may say so… It was a big pain. First off we had the issue of every service doing TLS in their own way and having to configure (or even enable the configuration) them for each technology with all their own knobs and handles. Some services were even hard-coding ‘http’ in their endpoints, or were limited to just using IPs (not FQDNs). These are details and nits, but still stuff that you have to do and takes up time.

The service mesh addresses this issue by allowing you to offload that to a proxy, which is where you configure TLS. So there is ONE way to set things up. Yes, it has its own knobs and handles, but at least there is only one set of knobs and handles to worry about.

There’s also the issue of getting an acceptable PKI with all the necessary features, as opposed to copying in a bunch of certificates and forgetting the rest. For this, in TripleO, we used FreeIPA (which I still think was a good choice).

The way this is addressed by service mesh solutions depends on the implementation. Some solutions, such as Istio and Conduit, provide their own PKI solution, so you’ll get TLS by default. In other implementations you have to provide your own. Given that we already have a chosen PKI, it shouldn’t be too hard to take it into use for this purpose; although, Istio’s PKI (the one that I checked out in the conference) is not pluggable yet.

The proxy will also take care of metrics for you, so we could replace the OpenStack-specific OSProfiler and take that into use instead. This would give us more visibility on the overall OpenStack service performance, and help us identify bottle necks.

Finally, a potential benefit would be to take the service-discovery and loadbalancing capabilities into use:

  • We could reduce the amount of hops through the network, since service-to-service communication would no longer need to go through HAProxy in all cases (Which is what happens when a service needs to talk to keystone, for instance).

  • We could potentially deploy several versions of the same service at the same time, and do a rolling-upgrade with relative ease thanks to the proxy (Although this would only be possible for services using Oslo.Versioned objects and with zero-downtime upgrades figured out).

While this is not something we have in the timeline at the moment, I would like to investigate this approach further, as it seems to provide quite a lot of benefits.


The first project that I had in mind tracking was Istio, which is a service mesh implementation that’s been getting a lot of momentum lately. Istio uses Envoy as the default underlying proxy that does the actual heavy lifting, and provides several services for configuring, monitoring and securing your service mesh. They have their own CA component (that’s is now called Citadel) which uses the SPIFFE specification to identify workloads and effectively give them certificates (more on SPIFFE later).

There seems to be a lot of work on-going to make Istio’s configuration easier, these enhancements include an API to self-configure Istio (instead of using Custom Resource Definitions). This API will hopefully also address the update issues they’ve been seeing, and also enable configuration rollbacks.

Istio also handles policy for the mesh traffic. For this, there are two built-in policy adaptors: One based on Kubernetes’ RBAC, and the other one based on Open Policy Agent (more on OPA later).

Unfortunately, it seems that all the efforts are right now being placed on Kubernetes. So, if we would like to take Istio into there are several things we would need to work on first in order to have it address our needs:

  • Make the CA component extendible

    • Currently the CA component is not extendible, so either we ditch our FreeIPA solution, or we code the pluggability into “Citadel”
  • Make the CA auth customizable

    • The built-in CA auth only take Kubernetes into account, so not only would we need to get customizable auth policies into Istio, we would also need to come up with relevant policies to assure that we’re giving out certs to the correct workloads/components.

    • Right now we have some assurance that only specific hosts can request certificates, and they can only do so for specific services. This all thanks to FreeIPA’s kerberos instance. We would need to add similar support to Istio.

  • Make Istio run in environments that are not Kubernetes

    • The current configuration and deployment scripts are only meant for kubernetes. Making it run in other environments would require a significant effort, as well as re-packaging of all the components.

    • There are options to make Istio add VMs to the service mesh, but they still require Kubernetes to be running somewhere, and is limited to Google Cloud VMs. So this doesn’t necessarily help us.

Even though we could run Istio without some components to have an easier setup, It seems to me that adopting it would take a significant amount of effort.

If we want to take the benefits of the service mesh into use in TripleO, it might be better to take a slower approach, and just take fewer components into use, instead of going with the full-blown solution. This lead me to take a deeper look into just using Envoy. This conclusion was also inspired by the recommendations in other talks in the conference that mentioned how other companies started adopting the service mesh: going for a cautious and thoughtful approach instead of a full-on migration.


Envoy is a magical proxy that folks have been using to enable service mesh architectures in their deployments. While it’s not the only proxy out there, it seems to be getting a lot of momentum in the community.

It supports proxying several protocols, which include: HTTP, HTTP/2, gRPC, MongoDB, Redis, among others. It’ll also provide L3/L4 filtering, health checking and TLS termination. It also provides statistics (with statsd integration) and distributed tracing via plugins.

For a long time it was configured with static files, but it now has support for dynamic configuration via gRPC. This is called xDS API, and is what control planes need to implement in order to take Envoy into use (this is what Istio does, for instance). So, in order for us to take it into use in OpenStack, we would need to either expand and run their reference xDS API or implement our own (which is what other folks seem to be doing for some reason).

A nice feature of Envoy is it’s support for hot-restarts which is envoy’s ability to reload and even do a binary update without dropping connections. I can see this feature to be very useful for our updates/upgrades in TripleO.

Currently, it seems to me that if we want to experiment with proxies to try to bring service mesh benefits into TripleO, starting with Envoy and some services would be a good start.


There were a lot of talks about SPIFFE/SPIRE in Kubecon. Given that it’s a security component and it seems to be taken into use by several other projects, I decided to take a look at it.

SPIFFE’s main goal is to establish trust between workloads and have the workload answer the question “who am I?”. So basically it aims to establish the workload’s identity. SPIFFE is an open specification which defines the overall mechanisms and how the API should look like. It introduces a couple of concepts:


    • It’s how we identify the given workload

    • Takes the form of a URL such as the following: spiffe://

    • would be the trust domain (could be a kerberos realm?)

    • billing/payments would identify the workload.

  • SVID (SPIFFE Verifiable Identity Document)

    • The current proposal is an x509 certificate that contains your SPIFFE ID as part of the certificate’s SAN.

    • It’s meant to be a specification of the minimum requirements for a verifiable document, x509 is one implementation, but there could be more.

    • The advantage of the SVID being an x509 certificate, is that it could effectively be used for TLS, which is what Istio is doing.

SPIFFE then dictates ways that the workload could get its SVID, which is via customizable and deployer-defined attestation policies. The policies are executed by an agent that runs on every node, and there should be a central server that ultimately verifies the claims and provides the agents with the actual SVIDs.

The team provided a reference implementation called SPIRE. This implements the SPIFFE specification and contains code for the agents and the server. There is already Vault support, and work on-going to hook up the server to HSMs.

It communicates with the workloads via a unix domain socket, so there’s no explicit authentication to communicate with the API. It is then the responsibility of the node-agent to check if the workload’s request is actually valid. Which is where the attestation policies kick in.

SPIRE already has customizable attestation policies which we could extend, and it seems that some folks from VMWare already implemented a Kerberos-based attestation plugin which ended up in very interesting conversations. I can definitely see that attestor being used with the kerberos instance provided by FreeIPA.

Currently SPIRE uses short-lived certificates, but support for actual revocation is coming in later this year. There is still no decision as to what mechanism will be used (could be CRLs or OCSP).

There is also another limitation, which is HA support. Currently SPIRE is implemented with SQLite and assumes one server node. How to get SPIRE to use a distributed database and make it scale is still an active problem the team is tackling.

There will also be a public security audit of the code in the near future.

Unfortuntely, even though Istio uses the SPIFFE specification for it’s CA (Citadel), it doesn’t use SPIRE, and instead contains its own implementation in the code-base. Asking around, it seems that the reason is to not lock in both project’s speeds together; so this allows Istio to move at it’s own pace.

Open Policy Agent

Open Policy Agent aims to unify policy configurations. It takes the form of an agent that your service communicates with in order to enforce the policy decision. It has it’s own format to configure policies which the agent interprets.

It seems to be getting some adoption, with integration with Istio and Kubernetes.

The main reason I took a look into it, was because I thought it would be a nice way to get the centralized policy policy story going for OpenStack. This would require us to implement an OPA driver in oslo in order to do policy and have an agent running with each OpenStack service. Unfortunately it seems we would need to implement a control plane for OPA (centralized configuration), since currently only the agent is open source. So we would have an OpenStack specific control plane that can read the already-existing policy.json files and transforms them into OPA documents; these would then be taken into use by the agents. The separate agent approach would give us the advantage that we wouldn’t need to reload OpenStack services in order to apply new policies (although this is not a very common operation). Another benefit would be to have the same policy format for Kubernetes and OpenStack.


The conference was great and gave me a lot of ideas that we could take into use in OpenStack. Although we might not use all of them (or even none of them, time will tell), I still learned a lot and got me very excited about the future in the cloud industry. I wish to see more interaction between the Cloud Native and the OpenStack communities, as I think there are a lot of convergence points where we could use the wisdom of both communities. I really hope I can attend again.

May 07, 2018 12:58 PM

May 04, 2018

Ben Nemec

OpenStack Virtual Baremetal on a Public Cloud


At long last, OVB has reached the goal we set for it way back when it was more idea than reality. The plan was to come up with a system where we could test baremetal deployment against OpenStack instances in an arbitrary cloud. That would allow something like TripleO CI to scale, for all practical purposes, infinitely. For years this wasn't possible because OVB required some configuration and/or hacks that were not appropriate for production clouds, which limited it to use in specific CI-oriented clouds. Theoretically it has been possible to use OVB on normal clouds for a couple of years now, but in practice public clouds were either running OpenStack versions that were too old or didn't expose the necessary features. Fortunately, this is no longer true.

Enter Vexxhost (I should note that I have no affiliation with Vexxhost). Generally speaking, the OVB requirements are:

  • OpenStack Mitaka or newer
  • Heat
  • Access to the Neutron port-security extension
  • The ability to upload images

That may not be an exhaustive list, but it covers the things that frequently blocked me from running OVB on a cloud. Vexxhost ticks all the boxes.


First, the OVB on Public Cloud demo video. As I mentioned in the video, there are some details that I glossed over in the interest of time (the video is nearly 20 minutes as it is). Here's a more complete explanation of those:

  • Quota. The default quota when you create an account on Vexxhost is somewhat restrictive for OVB use. You can fit an OVB environment into it, but you have to use the absolute minimum sizes for each instance. In some cases this may not work well. As I recall, the main restriction was CPU cores. To address this, just open a support ticket and explain what you're doing. I got my cpu core limit raised to 50, which enabled any nonha configuration I wanted. If you're doing an ha deployment you may need to have some other quota items raised, but you'll have to do the math on that.
  • Performance. Performance was a mixed bag, which is one of the downsides of running in a general purpose cloud. Some of my test runs were as fast as my dedicated local cloud, others were much slower.
  • Flavor disk sizes. As noted in the video, some of the Vexxhost flavors have a disk size of 0. Initially I thought this meant they could only be used with boot from volume, but fortunately it turns out you can still boot instances from ephemeral storage. This is important because on a public cloud you need to be able to nova rebuild the baremetal instances between deployments so they can PXE boot again. Nova can't currently rebuild instances booted from volume, so make sure to avoid doing that with OVB.

    Because of the 0 disk size, the virtual size of the images you boot will determine how much storage your instances get. By default, the CentOS 7 image only has 8 GB. That is not enough for a TripleO undercloud, although it's fine for the BMC. This can be worked around by either using qemu-img to resize a stock CentOS image and upload it to Glance, or by snapshotting an instance booted from a flavor that has a larger disk size. I did the latter because it allowed me to make some customizations (injecting ssh keys, setting a root password, etc.) to my base undercloud image. Either should work though.

    The original OVB ipxe-boot image has a similar problem. There is now an ipxe-boot-41 image with a virtual size of 41 GB that should provide enough storage for most deployment scenarios. If it doesn't, this image can also be resized with qemu-img.

    Another impact of this configuration is that the nodes.json created by build-nodes-json may have an incorrect disk size. It currently can't determine the size of a disk in an instance booted from a flavor with a 0 disk size. There are two options to deal with this. First, nodes.json can be hand-edited before importing to Ironic. Second, introspection can be run on node import, which is what I did in the video. It's a bit cleaner and demonstrates that introspection functionality works as expected. Introspection will look at the instance details from the inside so it can determine the correct disk size.

  • Cost. Obviously public cloud resources are not free. If you created the environment I used in my demo and left it running for a full month, at the current Vexxhost prices it would cost around $270 US. That's just for the instances, there will also be some small cost for image storage and bandwidth, although in my experience those would be negligible compared to the per-instance costs. That's not pocket change, but compared to the cost for purchasing and administering your own cloud it may be worth it.
  • [Edit 2018-5-7] Baremetal rebuilds. This is mentioned in the video, but it's important so I wanted to reiterate it here too. You must rebuild the baremetal instances between deployments in a public cloud environment. There is a rebuild-baremetal script provided that can automate this for you. In the case of the demo environment, it would have been called like this: rebuild-baremetal 2 baremetal demo. Note that this is run using the host cloud credentials, not the undercloud.

by bnemec at May 04, 2018 06:04 PM

March 19, 2018

Giulio Fidente

Ceph integration topics at OpenStack PTG

I wanted to share a short summary of the discussions happened around the Ceph integration (in TripleO) at the OpenStack PTG.

ceph-{container,ansible} branching

Together with John Fulton and Guillaume Abrioux (and after PTG, Sebastien Han) we put some thought into how to make the Ceph container images and ceph-ansible releases fit better the OpenStack model; the container images and ceph-ansible are in fact loosely coupled (not all versions of the container images work with all versions of ceph-ansible) and we wanted to move from a "rolling release" into a "point release" approach, mainly to permit regular maintenance of the previous versions known to work with the previous OpenStack versions. The plan goes more or less as follows:

  • ceph-{container,ansible} should be released together with the regular ceph updates
  • ceph-container will start using tags and stable branches like ceph-ansible does

The changes for the ceph/daemon docker images are visible already:

Multiple Ceph clusters

In the attempt to support better the "edge computing" use case, we discussed adding support for the deployment of multiple Ceph clusters in the overcloud.

Together with John Fulton and Steven Hardy (and after PTG, Gregory Charot) we realized this could be done using multiple stacks and by doing so, hopefully simplify managament of the "cells" and avoid potential issues due to orchestration of large clusters.

Much of this will build on Shardy's blueprint to split the control plane, see spec at:

The multiple Ceph clusters specifics will be tracked via another blueprint:

ceph-ansible testing with TripleO

We had a very good chat with John Fulton, Guillaume Abrioux, Wesley Hayutin and Javier Pena on how to get tested new pull requests for ceph-ansible with TripleO; basically trigger an existing TripleO scenario on changes proposed to ceph-ansible.

Given ceph-ansible is hosted on github, Wesley's and Javier suggested this should be possible with Zuul v3 and volunteered to help; some of the complications are about building an RPM from uncommitted changes for testing.

Move ceph-ansible triggering from workflow_tasks to external_deploy_tasks

This is a requirement for the Rocky release; we want to migrate away from using workflow_tasks and use external_deploy_tasks instead, to integrate into the "config-download" mechanism.

This work is tracked via a blueprint and we have a WIP submission on review:

We're also working with Sofer Athlan-Guyot on the enablement of Ceph in the upgrade CI jobs and with Tom Barron on scenario004 to deploy Manila with Ganesha (and CephFS) instead of the CephFS native backend.

Hopefully I didn't forget much; to stay updated on the progress join #tripleo on freenode or check our integration squad status at:

by Giulio Fidente at March 19, 2018 02:32 AM

March 06, 2018

Marios Andreou

My summary of the OpenStack Rocky PTG in Dublin

My summary of the OpenStack Rocky PTG in Dublin

I was fortunate to be part of the OpenStack PTG in Dublin this February. Here is a summary of the sessions I was able to be at. In the end the second day of the TripleO meetup thursday was disrupted as we had to leave the PTG venue. However we still managed to cover a wide range of topics some of which are summarized here.

In short and in the order attended: * FFU * Release cycles * TripleO


  • session etherpad
  • There are at least 5 different ways of doing FFU! Deployment projects update (tripleo, openstack-ansible, kolla, charms)
  • Some folks trying to do it manually (via operator feedback)
  • We will form a SIG (freenode #openstack-upgrades? ) –> first order of business is documenting something! Agreeing on best practices when FFU. –> meetings every 2 weeks?

Release Cycles

  • session etherpad
  • Release cadence to stay at 6 months for now. Wide discussion about the potential impacts of a longer release cycle including maintenance of stable branches, deployment project/integration testing and d/stream product release cycles, marketing, documentation and others. In the end the merits of a frequent upstream release cycle won, or at least, there was no consensus about getting a longer cycle.
  • On the other hand operators still think upgrades suck and don’t want to do it every six months. FFU is being relied on as the least painfull way to do upgrades at a longer cadence than the upstream 6 month development cycle which for now will stay as is.
  • There will be an extended maintenance tag or policy introduced for projects that will support the LTS long term support for stable branches


  • main tracking etherpad

  • retro session (emilienm) session etherpad some main points here are ‘do more and better ci’, communicate more and review at least a bit outside your squad, improve bugs triage, bring back deepdives.

  • ci session (weshay) session etherpad some main points here are ‘we need more attention on promotion’, upcoming features like new jobs (containerized undercloud, upgrades jobs), more communication with squads (upgrades ongoing for ex and continue to integrate the tripleo-upgrade role), python3 testing.

  • config download (slagle) session etherpad some main points are Rocky will bring config download and ansible-playbook worfklow for deployment of the environment, not just upgrade.

  • all in one (dprince) session etherpad some main points: using containerized undercloud have an ‘all-in-one’ role with only those services you need for your development at the given time. Some discussion around the potential CLI and pointers to more info

  • tripleo for generic provisioning (shadower) session etherpad some main points are re-using the config download with external_deploy_tasks (idea is kubernetes or openshift deployed in a tripleo overcloud), some work still needed on the interfaces and discussion around ironic nodes and ansible.

  • upgrades (marios o/, chem, jistr, lbezdick) at session etherpad , some main points are improvements in the ci - tech debt (moving to using the tripleo-upgrade role now), containerized undercloud upgrade is coming in Rocky (emilien investigating), Rocky will be a stabilization cycle with focus on improvements to the operator experience including validations, backup/restore, documentation and cli/ui. Integration with UI might be considered during Rocky to be revisitied with UI squad.

  • containerized undercloud (dprince, emilienm) session etherpad dprince gave a demonstration of a running containerized undercloud environment and reviewed the current work from the trello board. It is running well today and we can consider switching to default containerized undercloud in Rocky.

  • multiple ceph clusters (gfidente, johfulto), linked bug , discussion around possible approaches including having multiple heat stacks. gfidente or jfulton are better sources of info you are interested in this feature.

  • workflows api (thrash) session etherpad , some main points are fixing inconsistencies in workflows (should all have an output value, and not trying to get that from a zaqar message) and fixing usability, make a v2 tripleo mistral workflows api (tripleo-common) and re-organise the directories moving existing things under v1, look into optimizing the calls to swift to avoid a large number of individual object GET as currently happens.

  • UI (jtomasek) session etherpad some main points here are adding UI support for the new composable networks configuration, integration with coming config-download deployment, continue to increase UI/CLI feature parity, allow deployment of multiple plans, prototype workflows to derive parameters for the operator based on input for specific scenarios (like HCI), investigate root device hints support and setting physical_network on particular nodes. Florian led a side session in the Hotel on Thursday morning after we were kicked out of Croke Park stadium because nodublin where we discussed allowing operators to upload customvalidations and prototyping the use of swift for storing validations.

  • You might note that there are errors in the html validator for this post, but its late here and I’m in no mood to fight that right now. Yes, I know. cool story bro

March 06, 2018 03:00 PM

February 09, 2018

Steven Hardy

Debugging TripleO revisited - Heat, Ansible & Puppet

Some time ago I wrote a post about debugging TripleO heat templates, which contained some details of possible debug workflows when TripleO deployments fail.

In recent releases (since the Pike release) we've made some major changes to the TripleO architecture - we makes more use of Ansible "under the hood", and we now support deploying containerized environments.  I described some of these architectural changes in a talk at the recent OpenStack Summit in Sydney.

In this post I'd like to provide a refreshed tutorial on typical debug workflow, primarily focussing on the configuration phase of a typical TripleO deployment, and with particular focus on interfaces which have changed or are new since my original debugging post.

We'll start by looking at the deploy workflow as a whole, some heat interfaces for diagnosing the nature of the failure, then we'll at how to debug directly via Ansible and Puppet.  In a future post I'll also cover the basics of debugging containerized deployments.

The TripleO deploy workflow, overview

A typical TripleO deployment consists of several discrete phases, which are run in order:

Provisioning of the nodes

  1. A "plan" is created (heat templates and other files are uploaded to Swift running on the undercloud
  2. Some validation checks are performed by Mistral/Heat then a Heat stack create is started (by Mistral on the undercloud)
  3. Heat creates some groups of nodes (one group per TripleO role e.g "Controller"), which results in API calls to Nova
  4. Nova makes scheduling/placement decisions based on your flavors (which can be different per role), and calls Ironic to provision the baremetal nodes
  5. The nodes are provisioned by Ironic

This first phase is the provisioning workflow, after that is complete and the nodes are reported ACTIVE by nova (e.g the nodes are provisioned with an OS and running).

Host preparation

The next step is to configure the nodes in preparation for starting the services, which again has a specific workflow (some optional steps are omitted for clarity):

  1. The node networking is configured, via the os-net-config tool
  2. We write hieradata for puppet to the node filesystem (under /etc/puppet/hieradata/*)
  3. We write some data files to the node filesystem (a puppet manifest for baremetal configuration, and some json files that are used for container configuration)

Service deployment, step-by-step configuration

The final step is to deploy the services, either on the baremetal host or in containers, this consists of several tasks run in a specific order:

  1. We run puppet on the baremetal host (even in the containerized architecture this is still needed, e.g to configure the docker daemon and a few other things)
  2. We run "" to generate the configuration files for each enabled service (this only happens once, on step 1, for all services)
  3. We start any containers enabled for this step via the "paunch" tool, which translates some json files into running docker containers, and optionally does some bootstrapping tasks.
  4. We run again (with a different configuration, only on one node the "bootstrap host"), this does some bootstrap tasks that are performed via puppet, such as creating keystone users and endpoints after starting the service.

Note that these steps are performed repeatedly with an incrementing step value (e.g step 1, 2, 3, 4, and 5), with the exception of the "" config generation which we only need to do once (we just generate the configs for all services regardless of which step they get started in).

Below is a diagram which illustrates this step-by-step deployment workflow:
TripleO Service configuration workflow

The most common deployment failures occur during this service configuration phase of deployment, so the remainder of this post will primarily focus on debugging failures of the deployment steps.


Debugging first steps - what failed?

Heat Stack create failed.

Ok something failed during your TripleO deployment, it happens to all of us sometimes!  The next step is to understand the root-cause.

My starting point after this is always to run:

openstack stack failures list --long <stackname>

(undercloud) [stack@undercloud ~]$ openstack stack failures list --long overcloud
resource_type: OS::Heat::StructuredDeployment
physical_resource_id: 421c7860-dd7d-47bd-9e12-de0008a4c106
status_reason: |
Error: resources[0]: Deployment to server failed: deploy_status_code : Deployment exited with non-zero status code: 2
deploy_stdout: |

PLAY [localhost] ***************************************************************


TASK [Run puppet host configuration for step 1] ********************************
ok: [localhost]

TASK [debug] *******************************************************************
fatal: [localhost]: FAILED! => {
"changed": false,
"failed_when_result": true,
"outputs.stdout_lines|default([])|union(outputs.stderr_lines|default([]))": [
"Debug: Runtime environment: puppet_version=4.8.2, ruby_version=2.0.0, run_mode=user, default_encoding=UTF-8",
"Error: Evaluation Error: Error while evaluating a Resource Statement, Unknown resource type: 'ugeas' at /etc/puppet/modules/tripleo/manifests/profile/base/docker.pp:181:5 on node overcloud-controller-0.localdomain"
to retry, use: --limit @/var/lib/heat-config/heat-config-ansible/8dd0b23a-acb8-4e11-aef7-12ea1d4cf038_playbook.retry

PLAY RECAP *********************************************************************
localhost : ok=18 changed=12 unreachable=0 failed=1

We can tell several things from the output (which has been edited above for brevity), firstly the name of the failing resource

  • The error was on one of the Controllers (ControllerDeployment)
  • The deployment failed during the per-step service configuration phase (the AllNodesDeploySteps part tells us this)
  • The failure was during the first step (Step1.0)
Then we see more clues in the deploy_stdout, ansible failed running the task which runs puppet on the host, it looks like a problem with the puppet code.

With a little more digging we can see which node exactly this failure relates to, e.g we copy the SoftwareDeployment ID from the output above, then run:

(undercloud) [stack@undercloud ~]$ openstack software deployment show 421c7860-dd7d-47bd-9e12-de0008a4c106 --format value --column server_id
(undercloud) [stack@undercloud ~]$ openstack server list | grep 29b3c254-5270-42ae-8150-9fc3f67d3d89
| 29b3c254-5270-42ae-8150-9fc3f67d3d89 | overcloud-controller-0 | ACTIVE | ctlplane= | overcloud-full | oooq_control |

Ok so puppet failed while running via ansible on overcloud-controller-0.


Debugging via Ansible directly

Having identified that the problem was during the ansible-driven configuration phase, one option is to re-run the same configuration directly via ansible-ansible playbook, so you can either increase verbosity or potentially modify the tasks to debug the problem.

Since the Queens release, this is actually very easy, using a combination of the new "openstack overcloud config download" command and the tripleo dynamic ansible inventory.

(undercloud) [stack@undercloud ~]$ openstack overcloud config download
The TripleO configuration has been successfully generated into: /home/stack/tripleo-VOVet0-config
(undercloud) [stack@undercloud ~]$ cd /home/stack/tripleo-VOVet0-config
(undercloud) [stack@undercloud tripleo-VOVet0-config]$ ls
common_deploy_steps_tasks.yaml external_post_deploy_steps_tasks.yaml templates
Compute global_vars.yaml update_steps_playbook.yaml
Controller group_vars update_steps_tasks.yaml
deploy_steps_playbook.yaml post_upgrade_steps_playbook.yaml upgrade_steps_playbook.yaml
external_deploy_steps_tasks.yaml post_upgrade_steps_tasks.yaml upgrade_steps_tasks.yaml

Here we can see there is a "deploy_steps_playbook.yaml", which is the entry point to run the ansible service configuration steps.  This runs all the common deployment tasks (as outlined above) as well as any service specific tasks (these end up in task include files in the per-role directories, e.g Controller and Compute in this example).

We can run the playbook again on all nodes with the tripleo-ansible-inventory from tripleo-validations, which is installed by default on the undercloud:

(undercloud) [stack@undercloud tripleo-VOVet0-config]$ ansible-playbook -i /usr/bin/tripleo-ansible-inventory deploy_steps_playbook.yaml --limit overcloud-controller-0
TASK [Run puppet host configuration for step 1] ********************************************************************
ok: []

TASK [debug] *******************************************************************************************************
fatal: []: FAILED! => {
"changed": false,
"failed_when_result": true,
"outputs.stdout_lines|default([])|union(outputs.stderr_lines|default([]))": [
"Notice: hiera(): Cannot load backend module_data: cannot load such file -- hiera/backend/module_data_backend",
"exception: connect failed",
"Warning: Undefined variable '::deploy_config_name'; ",
" (file & line not available)",
"Warning: Undefined variable 'deploy_config_name'; ",
"Error: Evaluation Error: Error while evaluating a Resource Statement, Unknown resource type: 'ugeas' at /etc/puppet/modules/tripleo/manifests/profile
/base/docker.pp:181:5 on node overcloud-controller-0.localdomain"


NO MORE HOSTS LEFT *************************************************************************************************
to retry, use: --limit @/home/stack/tripleo-VOVet0-config/deploy_steps_playbook.retry

PLAY RECAP ********************************************************************************************************* : ok=56 changed=2 unreachable=0 failed=1

Here we can see the same error is reproduced directly via ansible, and we made use of the --limit option to only run tasks on the overcloud-controller-0 node.  We could also have added --tags to limit the tasks further (see tripleo-heat-templates for which tags are supported).

If the error were ansible related, this would be a good way to debug and test any potential fixes to the ansible tasks, and in the upcoming Rocky release there are plans to switch to this model of deployment by default.


Debugging via Puppet directly

Since this error seems to be puppet related, the next step is to reproduce it on the host (obviously the steps above often yield enough information to identify the puppet error, but this assumes you need to do more detailed debugging directly via puppet):

Firstly we log on to the node, and look at the files in the /var/lib/tripleo-config directory.

(undercloud) [stack@undercloud tripleo-VOVet0-config]$ ssh heat-admin@
Warning: Permanently added '' (ECDSA) to the list of known hosts.
Last login: Fri Feb 9 14:30:02 2018 from gateway
[heat-admin@overcloud-controller-0 ~]$ cd /var/lib/tripleo-config/
[heat-admin@overcloud-controller-0 tripleo-config]$ ls
docker-container-startup-config-step_1.json docker-container-startup-config-step_4.json puppet_step_config.pp
docker-container-startup-config-step_2.json docker-container-startup-config-step_5.json
docker-container-startup-config-step_3.json docker-container-startup-config-step_6.json

The puppet_step_config.pp file is the manifest applied by ansible on the baremetal host

We can debug any puppet host configuration by running puppet apply manually. Note that hiera is used to control the step value, this will be at the same value as the failing step, but it can also be useful sometimes to manually modify this for development testing of different steps for a particular service.

[root@overcloud-controller-0 tripleo-config]# hiera -c /etc/puppet/hiera.yaml step
[root@overcloud-controller-0 tripleo-config]# cat /etc/puppet/hieradata/config_step.json
{"step": 1}[root@overcloud-controller-0 tripleo-config]# puppet apply --debug puppet_step_config.pp
Error: Evaluation Error: Error while evaluating a Resource Statement, Unknown resource type: 'ugeas' at /etc/puppet/modules/tripleo/manifests/profile/base/docker.pp:181:5 on node overcloud-controller-0.localdomain

Here we can see the problem is a typo in the /etc/puppet/modules/tripleo/manifests/profile/base/docker.pp file at line 181, I look at the file, fix the problem (ugeas should be augeas) then re-run puppet apply to confirm the fix.

Note that with puppet module fixes you will need to get the fix either into an updated overcloud image, or update the module via deploy artifacts for testing local forks of the modules.

That's all for today, but in a future post, I will cover the new container architecture, and share some debugging approaches I have found helpful when deployment failures are container related.

by Steve Hardy ( at February 09, 2018 05:04 PM

December 11, 2017

James Slagle

TripleO and Ansible deployment (Part 1)

In the Queens release of TripleO, you’ll be able to use Ansible to apply the
software deployment and configuration of an Overcloud.

Before jumping into some of the technical details, I wanted to cover some
background about how the Ansible integration works along side some of the
existing tools in TripleO.

The Ansible integration goes as far as offering an alternative to the
communication between the existing Heat agent (os-collect-config) and the Heat
API. This alternative is opt-in for Queens, but we are exploring making it the
default behavior for future releases.

The default behavior for Queens (and all prior releases) will still use the
model where each Overcloud node has a daemon agent called os-collect-config
that periodically polls the Heat API for deployment and configuration data.
When Heat provides updated data, the agent applies the deployments, making
changes to the local node such as configuration, service management,
pulling/starting containers, etc.

The Ansible alternative instead uses a “control” node (the Undercloud) running
ansible-playbook with a local inventory file and pushes out all the changes to
each Overcloud node via ssh in the typical Ansible fashion.

Heat is still the primary API, while the parameter and environment files that
get passed to Heat to create an Overcloud stack remain the same regardless of
which method is used.

Heat is also still fully responsible for creating and orchestrating all
OpenStack resources in the services running on the Undercloud (Nova servers,
Neutron networks, etc).

This sequence diagram will hopefully provide a clear picture:

Replacing the application and transport layer of the deployment with Ansible
allows us to take advantage of features in Ansible that will hopefully make
deploying and troubleshooting TripleO easier:

  • Running only specific deployments
  • Including/excluding specific nodes or roles from an update
  • More real time sequential output of the deployment
  • More robust error reporting
  • Faster iteration and reproduction of deployments

Using Ansible instead of the Heat agent is easy. Just include 2 extra cli args
in the deployment command:

-e /path/to/templates/environments/config-download-environment.yaml \

Once Heat is done creating the stack (will be much faster than usual), a
separate Mistral workflow will be triggered that runs ansible-playbook to
finish the deployment. The output from ansible-playbook will be streamed to
stdout so you can follow along with the progress.

Here’s a demo showing what a stack update looks like:

(I suggest making the demo fully screen or watch it here:

Note that we don’t get color output from ansible-playbook since we are
consuming the stdout from a Zaqar queue. However, in my next post I will go
into how to execute ansible-playbook manually, and detail all of the related
files (inventory, playbooks, etc) that are available to interact with manually.

If you want to read ahead, have a look at the official documentation:


by James Slagle at December 11, 2017 03:19 PM

July 19, 2017

Giulio Fidente

Understanding ceph-ansible in TripleO

One of the goals for the TripleO Pike release was to introduce ceph-ansible as an alternative to puppet-ceph for the deployment of Ceph.

More specifically, to put operators in control of the playbook execution as if they were launching ceph-ansible from the commandline, except it would be Heat starting ceph-ansible at the right time during the overcloud deployment.

This demanded for some changes in different tools used by TripleO and went through a pretty long review process, eventually putting in place some useful bits for the future integration of Kubernetes and migration to an ansible driven deployment of the overcloud configuration steps in TripleO.

The idea was to add a generic functionality allowing triggering of a given Mistral workflow during the deployment of a service. Mistral could have then executed any action, including for example an ansible playbook, provided it was given all the necessay input data for the playbook to run and the roles list to build the hosts inventory.

This is how we did it.

Run ansible-playbook from Mistral (1)
An initial submission added support for the execution of ansible playbooks as workflow tasks in Mistral

A generic action for Mistral which workflows can use to run an ansible playbook. +2 to Dougal and Ryan.

Deploy external resources from Heat (2)
We also needed a new resource in Heat to be able to drive Mistral workflow executions so that we could orchestrate the executions like any other Heat resource. This is described much in detail in a Heat spec.

With these two, we could run an ansible playbook from a Heat resource, via Mistral. +2 to Zane and Thomas for the help! Enough to start messing in TripleO and glue things together.

Describe what/when to run in TripleO (3)
We added a mechanim in the TripleO templates to make it possible to describe, from within a service, a list of tasks or workflows to be executed at any given deployment step

There aren't restrictions on what the tasks or workflows in the new section should do. These might deploy the service or prepare the environment for it or execute code (eg. build Swift rings). The commit message explains how to use it:

    - name: my_action_name
      action: std.echo
        output: 'hello world'

The above snippet would make TripleO to run the Mistral std.echo action during the overcloud deployment, precisely at step 2, assuming you create a new service with the code above and enable it on a role.

For Ceph we wanted to run the new Mistral action (1) and needed to provide it with the config settings for the service, normally described within the config_settings structure of the service template.

Provide config_settings to the workflows (4)
The decision was to make available all config settings into the Mistral execution environment so that ansible actions could, for example, use them as extra_vars

Now all config settings normally consumed by puppet were available to the Mistral action and playbook settings could be added too, +2 Steven.

Build the data for the hosts inventory (5)
Together with the above, another small change provided into the execution environment a dictionary mapping every enabled service to the list of IP address of the nodes where the service is deployed

This was necessary to be able to build the ansible hosts inventory.

Create a workflow for ceph-ansible (6)
Having all pieces available to trigger the workflow and pass to it the service config settings, we needed the workflow which would run ceph-ansible plus some new, generic Mistral actions, to run smoothly multiple times (eg. stack updates)

This is the glue which runs a ceph-ansible playbook with the given set of parameters. +2 John.

Deploy Ceph via ceph-ansible (7)
Finally, the new services definition for Tripleo to deploy Ceph in containers via ceph-ansible, including a couple of params operators can use to push into the Mistral environment arbitrary extra_vars for ceph-ansible.

The deployment with ceph-ansible is activated with the ceph-ansible.yaml environment file.

Interestingly the templates to deploy Ceph using puppet-ceph are unchanged and continue to work as they used to so that for new deployments it is possible to use alternatively the new implementation with ceph-ansible or the pre-existing implementation using puppet-ceph. Only ceph-ansible allows for the deployment of Ceph in containers.

Big +2 also to Jiri (who doesn't even need a blog or twitter) and all the people who helped during the development process with feedback, commits and reviews.

Soon another article with some usage examples and debugging instructions!

by Giulio Fidente at July 19, 2017 09:00 AM

July 07, 2017

Julie Pichon

TripleO Deep Dive: Internationalisation in the UI

Yesterday, as part of the TripleO Deep Dives series I gave a short introduction to internationalisation in TripleO UI: the technical aspects of it, as well as a quick overview of how we work with the I18n team.

You can catch the recording on BlueJeans or YouTube, and below's a transcript.


Life and Journey of a String

Internationalisation was added to the UI during Ocata - just a release ago. Florian implemented most of it and did the lion's share of the work, as can be seen on the blueprint if you're curious about the nitty-gritty details.

Addition to the codebase

Here's an example patch from during the transition. On the left you can see how things were hard-coded, and on the right you can see the new defineMessages() interface we now use. Obviously new patches should directly look like on the right hand-side nowadays.

The defineMessages() dictionary requires a unique id and default English string for every message. Optionally, you can also provide a description if you think there could be confusion or to clarify the meaning. The description will be shown in Zanata to the translators - remember they see no other context, only the string itself.

For example, a string might sound active like if it were related to an action/button but actually be a descriptive help string. Or some expressions are known to be confusing in English - "provide a node" has been the source of multiple discussions on list and live so might as well pre-empt questions and offer additional context to help the translators decide on an appropriate translation.

Extraction & conversion

Now we know how to add an internationalised string to the codebase - how do these get extracted into a file that will be uploaded to Zanata?

All of the following steps are described in the translation documentation in the tripleo-ui repository. Assuming you've already run the installation steps (basically, npm install):

$ npm run build

This does a lot more than just extracting strings - it prepares the code for being deployed in production. Once this ends you'll be able to find your newly extracted messages under the i18n directory:

$ ls i18n/extracted-messages/src/js/components

You can see the directory structure is kept the same as the source code. And if you peek into one of the files, you'll note the content is basically the same as what we had in our defineMessages() dictionary:

$ cat i18n/extracted-messages/src/js/components/Login.json
    "id": "UserAuthenticator.authenticating",
    "defaultMessage": "Authenticating..."
    "id": "Login.username",
    "defaultMessage": "Username"
    "id": "Login.usernameRequired",
    "defaultMessage": "Username is required."

However, JSON is not a format that Zanata understands by default. I think the latest version we upgraded to, or the next one might have some support for it, but since there's no i18n JSON standard it's somewhat limited. In open-source software projects, po/pot files are generally the standard to go with.

$ npm run json2pot

> tripleo-ui@7.1.0 json2pot /home/jpichon/devel/tripleo-ui
> rip json2pot ./i18n/extracted-messages/**/*.json -o ./i18n/messages.pot

> [react-intl-po] write file -> ./i18n/messages.pot ✔️

$ cat i18n/messages.pot
msgid ""
msgstr ""
"POT-Creation-Date: 2017-07-07T09:14:10.098Z\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"MIME-Version: 1.0\n"
"X-Generator: react-intl-po\n"

#: ./i18n/extracted-messages/src/js/components/nodes/RegisterNodesDialog.json
#. [RegisterNodesDialog.noNodesToRegister] - undefined
msgid ""No Nodes To Register""
msgstr ""

#: ./i18n/extracted-messages/src/js/components/nodes/NodesToolbar/NodesToolbar.json
#. [Toolbar.activeFilters] - undefined
#: ./i18n/extracted-messages/src/js/components/validations/ValidationsToolbar.json
#. [Toolbar.activeFilters] - undefined
msgid "Active Filters:"
msgstr ""

#: ./i18n/extracted-messages/src/js/components/nodes/RegisterNodesDialog.json
#. [RegisterNodesDialog.addNew] - Small button, to add a new Node
msgid "Add New"
msgstr ""

#: ./i18n/extracted-messages/src/js/components/plan/PlanFormTabs.json
#. [PlanFormTabs.addPlanName] - Tooltip for "Plan Name" form field
msgid "Add a Plan Name"
msgstr ""

This messages.pot file is what will be automatically uploaded to Zanata.

Infra: from the git repo, to Zanata

The following steps are done by the infrastructure scripts. There's infra documentation on how to enable translations for your project, in our case as the first internationalised JavaScript project we had to update the scripts a little as well. This is useful to know if an issue happens with the infra jobs; debugging will probably bring you here.

The scripts live in the project-config infra repo and there are three files of interest for us:

In this case, is the file of interest to us: it simply sets up the project on line 76, then sends the pot file up to Zanata on line 115.

What does "setting up the project" entails? It's a function in, that pretty much runs the steps we talked about in the previous section, and also creates a config file to talk to Zanata.

Monitoring the post jobs

Post jobs run after a patch has already merged - usually to upload tarballs where they should be, update the documentation pages, etc, and also upload messages catalogues onto Zanata. Being a 'post' job however means that if something goes wrong, there is no notification on the original review so it's easy to miss.

Here's the OpenStack Health page to monitor 'post' jobs related to tripleo-ui. Scroll to the bottom - hopefully tripleo-ui-upstream-translation-update is still green! It's good to keep an eye on it although it's easy to forget. Thankfully, AJaeger from #openstack-infra has been great at filing bugs and letting us know when something does go wrong.

Debugging when things go wrong: an example

We had a couple of issues whereby a linebreak gets introduced into one of the strings, which works fine in JSON but breaks our pot file. If you look at the content from the bug (the full logs are no longer accessible):

2017-03-16 12:55:13.468428 | + zanata-cli -B -e push --copy-trans False
2017-03-16 12:55:15.391220 | [INFO] Found source documents:
2017-03-16 12:55:15.391405 | [INFO]            i18n/messages
2017-03-16 12:55:15.531164 | [ERROR] Operation failed: missing end-quote

You'll notice the first line is the last function we call in the script; for debugging that gives you an idea of the steps to follow to reproduce. The upstream Zanata instance also lets you create toy projects, if you want to test uploads yourself (this can't be done directly on the OpenStack Zanata instance.)

This particular newline issue has popped up a couple of times already. We're treating it with band-aids at the moment, ideally we'd get a proper test on the gate to prevent it from happening again: this is why this bug is still open. I'm not very familiar with JavaScript testing and haven't had a chance to look into it yet; if you'd like to give it a shot that'd be a useful contribution :)

Zanata, and contributing translations

The OpenStack Zanata instance lives at This is where the translators do their work. Here's the page for tripleo-ui, you can see there is one project per branch (stable/ocata and master, for now). Sort by "Percent Translated" to see the languages currently translated. Here's an example of the translator's view, for Spanish: you can see the English string on the left, and the translator fills in the right side. No context! Just strings.

At this stage of the release cycle, the focus would be on 'master,' although it is still early to do translations; there is a lot of churn still.

If you'd like to contribute translations, the I18n team has good documentation about how to go about how to do it. The short version: sign up on Zanata, request to join your language team, once you're approved - you're good to go!

Return of the string

Now that we have our strings available in multiple languages, it's time for another infra job to kick in and bring them into our repository. This is where comes in. We pull the po files from Zanata, convert them to JSON, then do a git commit that will be proposed to Gerrit.

The cleanup step does more than it might seem. It checks if files are translated over a certain ratio (~75% for code), which avoids adding new languages when there might only be one or two words translated (e.g. someone just testing Zanata to see how it works). Switching to your language and yet having the vast majority of the UI still appear in English is not a great user experience.

In theory, files that were added but are now below 40% should get automatically removed, however this doesn't quite work for JavaScript at the moment - another opportunity to help! Manual cleanups can be done in the meantime, but it's a rare event so not a major issue.

Monitoring the periodic jobs

Zanata is checked once a day every morning, there is an OpenStack Health page for this as well. You can see there are two jobs at the moment (hopefully green!), one per branch: tripleo-ui-propose-translation-update and tripleo-ui-propose-translation-update-ocata. The job should run every day even if there are no updates - it simply means there might not be a git review proposed at the end.

We haven't had issues with the periodic job so far, though the debugging process would be the same: figure out based on the failure if it is happening at the infra script stage or in one of our commands (e.g. npm run po2json), try to reproduce and fix. I'm sure super-helpful AJaeger would also let us know if he were to notice an issue here.

Automated patches

You may have seen the automated translations updates pop up on Gerrit. The commit message has some tips on how to review these: basically don't agonise over the translation contents as problems there should be handled in Zanata anyway, just make sure the format looks good and is unlikely to break the code. A JSON validation tool runs during the infra prep step in order to "prettify" the JSON blob and limit the size of the diffs, therefore once the patch  makes it out to Gerrit we know the JSON is well-formed at least.

Try to review these patches quickly to respect the translators' work. Not very nice to spend a lot of time on translating a project and yet not have your work included because no one was bothered to merge it :)

A note about new languages...

If the automated patch adds a new language, there'll be an additional step required after merging the translations in order to enable it: adding a string with the language name to a constants file. Until recently, this took 3 or 4 steps - thanks to Honza for making it much simpler!

This concludes the technical journey of a string. If you'd like to help with i18n tasks, we have a few related bugs open. They go from very simple low-hanging-fruits you could use to make your first contribution to the UI, to weird buttons that have translations available yet show in English but only in certain modals, to the kind of CI resiliency tasks I linked to earlier. Something for everyone! ;)

Working with the I18n team

It's really all about communication. Starting with...

Release schedule and string freezes

String freezes are noted on the main schedule but tend to fit the regular cycle-with-milestones work. This is a problem for a cycle-trailing project like tripleo-ui as we could be implementing features up to 2 weeks after the other projects, so we can't freeze strings that early.

There were discussions at the Atlanta PTG around whether the I18n should care at all about projects that don't respect the freeze deadlines. That would have made it impossible for projects like ours to ever make it onto the I18n official radar. The compromise was that cycle-trailing project should have a I18n cross-project liaison that communicates with the I18n PTL and team to inform them of deadlines, and also to ignore Soft Freeze and only do a Hard Freeze.

This will all be documented under an i18n governance tag; while waiting for it the notes from the sessions are available for the curious!

What's a String Freeze again?

The two are defined on the schedule: soft freeze means not allowing changes to strings, as it invalidates the translator's work and forces them to retranslate; hard freeze means no additions, changes or anything else in order to give translators a chance to catch up.

When we looked at Zanata earlier, there were translation percentages beside each language: the goal is always the satisfaction of reaching 100%. If we keep adding new strings then the goalpost keeps moving, which is discouraging and unfair.

Of course there's also an "exception process" when needed, to ask for permission to merge a string change with an explanation or at least a heads-up, by sending an email to the openstack-i18n mailing list. Not to be abused :)

Role of the I18n liaison

...Liaise?! Haha. The role is defined briefly on the Cross-Projects Liaison wiki page. It's much more important toward the end of the cycle, when the codebase starts to stabilise, there are fewer changes and translators look at starting their work to be included in the release.

In general it's good to hang out on the #openstack-i18n IRC channel (very low traffic), attend the weekly meeting (it alternates times), be available to answer questions, and keep the PTL informed of the I18n status of the project. In the case of cycle-trailing projects (quite a new release model still), it's also important to be around to explain the deadlines.

A couple of examples having an active liaison helps with:

  • Toward the end or after the release, once translations into the stable branch have settled, the stable translations get copied into the master branch on Zanata. The strings should still be fairly similar at that point and it avoids translators having to re-do the work. It's a manual process, so you need to let the I18n PTL know when there are no longer changes to stable/*.
  • Last cycle, because the cycle-trailing status of tripleo-ui was not correctly documented, a Zanata upgrade was planned right after the main release - which for us ended up being right when the codebase had stabilised enough and several translators had planned to be most active. Would have been solved with better, earlier communication :)


After the Ocata release, I sent a few screenshots of tripleo-ui to the i18n list so translators could see the result of their work. I don't know if anybody cared :-) But unlike Horizon, which has an informal test system available for translators to check their strings during the RC period, most of the people who volunteered translations had no idea what the UI looked like. It'd be cool if we could offer a test system with regular string updates next release - maybe just an undercloud on the new RDO cloud? Deployment success/failures strings wouldn't be verifiable but the rest would, while the system would be easier to maintain than a full dev TripleO environment - better than nothing. Perhaps an idea for the Queens cycle!

The I18n team has a priority board on the Zanata main page (only visible when logged in I think). I'm grateful to see TripleO UI in there! :) Realistically we'll never move past Low or perhaps Medium priority which is fair, as TripleO doesn't have the same kind of reach or visibility that Horizon or the installation guides do. I'm happy that we're included! The OpenStack I18n team is probably the most volunteer-driven team in OpenStack. Let's be kind, respect string freezes and translators' time! \o/


by jpichon at July 07, 2017 11:45 AM

April 14, 2017

Emilien Macchi

My Journey As An OpenStack PTL

This story explains why I started to stop working as a anarchistic-multi-tasking-schedule-driven and learnt how to become a good team leader.

How it started

March 2015, Puppet OpenStack project just moved under the Big Tent. What a success for our group!

One of the first step was to elect a Project Team Lead. Our group was pretty small (~10 active contributors) so we thought that the PTL would be just a facilitator for the group, and the liaison with other projects that interact with us.
I mean, easy, right?

At that time, I was clearly an unconsciously incompetent PTL. I thought I knew what I was doing to drive the project to success.

But situation evolved. I started to deal with things that I didn’t expect to deal with like making sure our team works together in a way that is efficient and consistent. I also realized nobody knew what
a PTL was really supposed to do (at least in our group), so I took care of more tasks, like release management, organizing Summit design sessions, promoting core reviewers, and welcoming newcomers.
That was the time where I realized I become a consciously incompetent PTL. I was doing things that nobody taught me before.

In fact, there is no book telling you how to lead an OpenStack project so I decided to jump in this black hole and hopefully I would make mistakes so I can learn something.


Set your own expectations

I made the mistake of engaging myself into a role where expectations were not cleared with the team. The PTL guide is not enough to clear expectations of what your team will wait from you. This is something you have to figure out with the folks you’re working with. You would be surprised by the diversity of expectations that project contributors have for their PTL.
Talk with your team and ask them what they want you to be and how they see you as a team lead.
I don’t think there is a single rule that works for all projects, because of the different cultures in OpenStack community.


Embrace changes

… and accept failures.
There is no project in OpenStack that didn’t had outstanding issues (technical and human).
The first step as a PTL is to acknowledge the problem and share it with your team. Most of the conflicts are self-resolved when everyone agrees that yes, there is a problem. It can be a code design issue or any other technical disagreement but also human complains, like the difficulty to start contributing or the lack of reward for very active contributors who aren’t core yet.
Once a problem is resolved: discuss with your team about how we can avoid the same situation in the future.
Make a retrospective if needed but talk and document the output.

I continuously encourage at welcoming all kind of changes in TripleO so we can adopt new technologies that will make our project better.

Keep in mind it has a cost. Some people will disagree but that’s fine: you might have to pick a rate of acceptance to consider that your team is ready to make this change.



We are humans and have limits. We can’t be everywhere and do everything.
We have to accept that PTLs are not supposed to be online 24/7. They don’t always have the best ideas and don’t always take the right decisions.
This is fine. Your project will survive.

I learnt that when I started to be PTL of TripleO in 2016.
The TripleO team has become so big that I didn’t realize how many interruptions I would have every day.
So I decided to learn how to delegate.
We worked together and created TripleO Squads where each squad focus on a specific area of TripleO.
Each squad would be autonomous enough to propose their own core reviewers or do their own meetings when needed.
I wanted small teams working together, failing fast and making quick iterations so we could scale the project, accept and share the work load and increase the trust inside the TripleO team.

This is where I started to be a Consciously Competent PTL.


Where am I now

I have reached a point where I think that projects wouldn’t need a PTL to run fine if they really wanted.
Instead, I start to believe about some essential things that would actually help to get rid of this role:

  • As a team, define the vision of the project and document it. It will really help to know where we want to
    go and clear all expectations about the project.
  • Establish trust to each individual by default and welcome newcomers.
  • Encourage collective and distributed leadership.
  • Try, Do, Fail, Learn, Teach. and start again. Don’t stale.

This long journey helped me to learn many things in both technical and human areas. It has been awesome to work with such groups so far.
I would like to spend more time on technical work (aka coding) but also in teaching and mentoring new contributors in OpenStack.
Therefore, I won’t be PTL during the next cycle and my hope is to see new leaders in TripleO, who would come up with fresh ideas and help us to keep TripleO rocking.


Thanks for reading so far, and also thanks for your trust.

by Emilien at April 14, 2017 08:56 PM

March 02, 2017

Julie Pichon

OpenStack Pike PTG: TripleO, TripleO UI | Some highlights

For the second part of the PTG (vertical projects), I mainly stayed in the TripleO room, moving around a couple of times to attend cross-project sessions related to i18n.

Although I always wish I understood more/everything, in the end my areas of interest (and current understanding!) in TripleO are around the UI, installing and configuring it, the TripleO CLI, and the tripleo-common Mistral workflows. Therefore the couple of thoughts in this post are mainly relevant to these - if you're looking for a more exhaustive summary of the TripleO discussions and decisions made during the PTG, I recommend reading the PTL's excellent thread about this on the dev list, and the associated etherpads.

Random points of interest

  • Containers is the big topic and had multiple sessions dedicated to it, both single and cross-projects. Many other sessions ended up revisiting the subject as well, sometimes with "oh that'll be solved with containers" and sometimes with "hm good but that won't work with containers."
  • A couple of API-breaking changes may need to happen in Tripleo Heat Templates (e.g. for NFV, passing a role mapping vs a role name around). The recommendation is to get this in as early as possible (by the first milestone) and communicate it well for out of tree services.
  • When needing to test something new on the CI, look at the existing scenarios and prioritise adding/changing something there to test for what you need, as opposed to trying to create a brand new job.
  • Running Mistral workflows as part of or after the deployment came up several times and was even a topic during a cross-project Heat / Mistral / TripleO sessions. Things can get messy, switching between Heat, Mistral and Puppet. Where should these workflows live (THT, tripleo-common)? Service-specific workflows (pre/post-deploy) are definitely something people want and there's a need to standardise how to do that. Ceph's likely to be the first to try their hand at this.
  • One lively cross-project session with OpenStack Ansible and Kolla was about parameters in configuration files. Currently whenever a new feature is added to Nova or whatever service, Puppet and so on need to be updated manually. The proposal is to make a small change to oslo.config to enable it to give an output in machine-readable YAML which can then be consumed (currently the config generated is only human readable). This will help with validations, and it may help to only have to maintain a structure as opposed to a template.
  • Heat folks had a feedback session with us about the TripleO needs. They've been super helpful with e.g. helping to improve our memory usage over the last couple of cycles. My takeaway from this session was "beware/avoid using YAQL, especially in nested stacks." YAQL is badly documented and everyone ends up reading the source code and tests to figure out how to things. Bringing Jinja2 into Heat or some kind of way to have repeated patterns from resources (e.g. based on a file) also came up and was cautiously acknowledged.
  • Predictable IP assignment on the control plane is a big enough issue that some people are suggesting dropping Neutron in the undercloud over it. We'd lose so many other benefits though, that it seems unlikely to happen.
  • Cool work incoming allowing built-in network examples to Just Work, based on a sample configuration. Getting the networking stuff right is a huge pain point and I'm excited to hear this should be achievable within Pike.

Python 3

Python 3 is an OpenStack community goal for Pike.

Tripleo-common and python-tripleoclient both have voting unit tests jobs for Python 3.5, though I trust them only moderately for a number of reasons. For example many of the tests tend to focus on the happy path and I've seen and fixed Python 3 incompatible code in exceptions several times (no 'message' attribute seems easy to get caught into), despite the unit testing jobs being all green. Apparently there are coverage jobs we could enable for the client, to ensure the coverage ratio doesn't drop.

Python 3 for functional tests was also brought up. We don't have functional tests in any of our projects and it's not clear the value we would get out of it (mocking servers) compared to the unit testing and all the integration testing we already do. Increasing unit test coverage was deemed a more valuable goal to pursue for now.

There are other issues around functional/integration testing with Python 3 which will need to be resolved (though likely not during Pike). For example our integration jobs run on CentOS and use packages, which won't be Python 3 compatible yet (cue SCL and the need to respin dependencies). If we do add functional tests, perhaps it would be easier to have them run on a Fedora gate (although if I recall correctly gating on Fedora was investigated once upon a time at the OpenStack level, but caused too many issues due to churn and the lack of long-term releases).

Another issue with Python 3 support and functional testing is that the TripleO client depends on Mistral server (due to the Series Of Unfortunate Dependencies I also mentioned in the last post). That means Mistral itself would need to fully support Python 3 as well.

Python 2 isn't going anywhere just yet so we still have time to figure things out. The conclusions, as described in Emilien's email seem to be:

  • Improve the unit test coverage
  • Enable the coverage job in CI
  • Investigate functional testing for python-tripleoclient to start with, see if it makes sense and is feasible

Sample environment generator

Currently environment files in THT are written by hand and quite inconsistent. This is also important for the UI, which needs to display this information. For example currently the environment general description is in a comment at the top of the file (if it exists at all), which can't be accessed programmatically. Dependencies between environment files are not described either.

To make up for this, currently all that information lives in the capabilities map but it's external to the template themselves, needs to be updated manually and gets out of sync easily.

The sample environment generator to fix this has been out there for a year, and currently has two blockers. First, it needs a way to determine which parameters are private (that is, parameters that are expected to be passed in by another template and shouldn't be set by the user).

One way could be to use a naming convention, perhaps an underscore prefix similar to Python. Parameter groups cannot be used because of a historical limitation, there can only be one group (so you couldn't be both Private and Deprecated). Changing Heat with a new feature like Nested Groups or generic Parameter Tags could be an option. The advantage of the naming convention is that it doesn't require any change to Heat.

From the UI perspective, validating if an environment or template is redefining parameters already defined elsewhere also matters. Because if it has the same name, then it needs to be set up with the same value everywhere or it's uncertain what the final value will end up as.

I think the second issue was that the general environment description can only be a comment at the moment, there is no Heat parameter to do this. The Heat experts in the room seemed confident this is non-controversial as a feature and should be easy to get in.

Once the existing templates are updated to match the new format, the validation should be added to CI to make sure that any new patch with environments does include these parameters. Having "description" show up as an empty string when generating a new environment will make it more obvious that something can/should be there, while it's easy to forget about it with the current situation.

The agreement was:

  • Use underscores as a naming convention to start with
  • Start with a comment for the general description

Once we get the new Heat description attribute we can move things around. If parameter tags get accepted, likewise we can automate moving things around. Tags would also be useful to the UI, to determine what subset of relevant parameters to display to the user in smaller forms (easier to understand that one form with several dozens of fields showing up all at once). Tags, rather than parameter groups are required because of the aforementioned issue: it's already used for deprecation and a parameter can only have one group.

Trusts and federation

This was a cross-project session together with Heat, Keystone and Mistral. A "Trust" lets you delegate or impersonate a user with a subset of their rights. From my experience in TripleO, this is particularly useful with long running Heat stacks as a authentication token expires after a few hours which means you lose the ability to do anything in the middle of an operation.

Trusts have been working very well for Heat since 2013. Before that they had to encrypt the user password in order to ask for a new token when needed, which all agreed was pretty horrible and not anything people want to go back to. Unfortunately with the federation model and using external Identity Providers, this is no longer possible. Trusts break, but some kind of delegation is still needed for Heat.

There were a lot of tangents about security issues (obviously!), revocation, expiration, role syncing. From what I understand Keystone currently validates Trusts to make sure the user still has the requested permissions (that the relevant role hasn't been removed in the meantime). There's a desire to have access to the entire role list, because the APIs currently don't let us check which role is necessary to perform a specific action. Additionally, when Mistral workflows launched from Heat get in, Mistral will create its own Trusts and Heat can't know what that will do. In the end you always kinda end up needing to do everything. Karbor is running into this as well.

No solution was discovered during the session, but I think all sides were happy enough that the problem and use cases have been clearly laid out and are now understood.

TripleO UI

Some of the issues relevant to the UI were brought up in other sessions, like standardising the environment files. Other issues brought up were around plan management, for example why do we use the Mistral environment in addition to Swift? Historically it looks like it's because it was a nice drop-in replacement for the defunct TripleO API and offered a similar API. Although it won't have an API by default, the suggestion is to move to using a file to store the environment during Pike and have a consistent set of templates: this way all the information related to a deployment plan will live in the same place. This will help with exporting/importing plans, which itself will help with CLI/UI interoperability (for instance there are still some differences in how and when the Mistral environment is generated, depending on whether you deployed with the CLI or the UI).

A number of other issues were brought up around networking, custom roles, tracking deployment progress, and a great many other topics but I think the larger problems around plan management was the only expected to turn into a spec, now proposed for review.

I18n and release models

After the UI session I left the TripleO room to attend a cross-project session about i18n, horizon and release models. The release model point is particularly relevant because the TripleO UI is a newly internationalised project as of Ocata and the first to be cycle-trailing (TripleO releases a couple of weeks after the main OpenStack release).

I'm glad I was able to attend this session. For one it was really nice to collaborate directly with the i18n and release management team, and catch up with a couple of Horizon people. For second it turns out tripleo-ui was not properly documented as cycle-trailing (fixed now!) and that led to other issues.

Having different release models is a source of headaches for the i18n community, already stretched thin. It means string freezes happen at different times, stable branches are cut at different points, which creates a lot of tracking work for the i18n PTL to figure which project is ready and do the required manual work to update Zanata upon branching. One part of the solution is likely to figure out if we can script the manual parts of this workflow so that when the release patch (which creates the stable branch) is merged, the change is automatically reflected in Zanata.

For the non-technical aspects of the work (mainly keeping track of deadlines and string freezes) the decision was that if you want to be translated, then you need to respect the same deadlines than the cycle-with-milestones projects do on the main schedule, and if a project doesn't want to - if it doesn't respect the freezes or cut branches when expected, then they will be dropped from the i18n priority dashboard in Zanata. This was particularly relevant for Horizon plugins, as there's about a dozen of them now with various degrees of diligence when it comes to doing releases.

These expectations will be documented in a new governance tag, something like i18n:translated.

Obviously this would mean that cycle-trailing projects would likely never be able to get the tag. The work we depend on lands late and so we continue making changes up to two weeks after each of the documented deadlines. ianychoi, the i18n PTL seemed happy to take these projects under the i18n wing and do the manual work required, as long as there is an active i18n liaison for the project communicating with the i18n team to keep them informed about freezes and new branches. This seemed to work ok for us during Ocata so I'm hopeful we can keep that model. It's not entirely clear to me if this will also be documented/included in the governance tag so I look forward to reading the spec once it is proposed! :)

In the case of tripleo-ui we're not a priority project for translations nor looking to be, but we still rely on the i18n PTL to create Zanata branches and merge translations for us, and would like to continue with being able to translate stable branches as needed.


The CI Q&A session on Friday morning was amazingly useful and unanimously agreed it should be moved to the documentation (not done yet). If you've ever scratched your head about something related to TripleO CI, have a look at the etherpad!

by jpichon at March 02, 2017 09:55 AM

January 31, 2017

Dougal Matthews

Interactive Mistral Workflows over Zaqar

It is possible to do some really nice automation with the Mistral Workflow engine. However, sometimes user input is required or desirable. I set about to write an interactive Mistral Workflow, one that could communicate with a user over Zaqar.

If you are not familiar with Mistral Workflows you may want to start here, here or here.

The Workflow

Okay, this is what I came up with.

version: '2.0'


    - input_queue: "workflow-input"
    - output_queue: "workflow-output"


      action: zaqar.queue_post
      retry: count=5 delay=1
        queue_name: <% $.output_queue %>
          body: "Send some input to '<% $.input_queue %>'"
      on-success: read_user_input

      pause-before: true
      action: zaqar.queue_pop
        queue_name: <% $.input_queue %>
        user_input: <% task(read_user_input).result[0].body %>
      on-success: done

      action: std.echo output=<% $.user_input %>
      action: zaqar.queue_post
      retry: count=5 delay=1
        queue_name: <% $.output_queue %>
          body: "You sent: '<% $.user_input %>'"

Breaking it down...

  1. The Workflow uses two queues one for input and one for output - it would be possible to use the same for both but this seemed simpler.

  2. On the first task, request_user_input, the Workflow sends a Zaqar message to the user requesting a message be sent to the input_queue.

  3. The read_user_input task pauses before it starts, see the pause-before: true. This means we can unpause the Workflow after we send a message. It would be possible to create a loop here that polls for messages, see below for more on this.

  4. After the input is provided, the Workflow must be un-paused manually. It then reads from the queue and sends the message back to the user via the output Zaqar queue.

See it in Action

We can demonstrate the Workflow with just the Mistral client. First you need to save it to a file and use the mistral workflow-create command to upload it.

First we trigger the Workflow execution.

$ mistral execution-create interactive-workflow
| Field             | Value                                |
| ID                | e8e2bfd5-3ae4-46db-9230-ada00a2c0c8c |
| Workflow ID       | bdd1253e-68f8-4cf3-9af0-0957e4a31631 |
| Workflow name     | interactive-workflow                 |
| Description       |                                      |
| Task Execution ID | <none>                               |
| State             | RUNNING                              |
| State info        | None                                 |
| Created at        | 2017-01-31 08:22:17                  |
| Updated at        | 2017-01-31 08:22:17                  |

The Workflow will complete the first task and then move to the PAUSED state before read_user_input. This can be seen with the mistral execution-list command.

In this Workflow we know there will now be a message in Zaqar now. The Mistral action zaqar.queue_pop can be used to receive it...

$ mistral run-action zaqar.queue_pop '{"queue_name": "workflow-output"}'
{"result": [{"body": "Send some input to 'workflow-input'", "age": 4, "queue": {"_metadata": null, "client": null, "_name": "workflow-output"}, "href": null, "ttl": 3600, "_id": "589049397dcad341ecfb72cf"}]}

The JSON is a bit hard to read, but you can see the message body Send some input to 'workflow-input'.

Great. We can do that with another Mistral action...

$ mistral run-action zaqar.queue_post '{"queue_name": "workflow-input", "messages":{"body": {"testing": 123}}}'
{"result": {"resources": ["/v2/queues/workflow-input/messages/589049447dcad341ecfb72d0"]}}

After sending the message back to the requested Workflow we can unpause it. This can be done like this...

$ mistral execution-update -s RUNNING e8e2bfd5-3ae4-46db-9230-ada00a2c0c8c
| Field             | Value                                |
| ID                | e8e2bfd5-3ae4-46db-9230-ada00a2c0c8c |
| Workflow ID       | bdd1253e-68f8-4cf3-9af0-0957e4a31631 |
| Workflow name     | interactive-workflow                 |
| Description       |                                      |
| Task Execution ID | <none>                               |
| State             | RUNNING                              |
| State info        | None                                 |
| Created at        | 2017-01-31 08:22:17                  |
| Updated at        | 2017-01-31 08:22:38                  |

Finally we can confirm it worked by getting a message back from the Workflow...

$ mistral run-action zaqar.queue_pop '{"queue_name": "workflow-output"}'
{"result": [{"body": "You sent: '{u'testing': 123}'", "age": 6, "queue": {"_metadata": null, "client": null, "_name": "workflow-output"}, "href": null, "ttl": 3600, "_id": "5890494f7dcad341ecfb72d1"}]}

You can see a new message is returned which shows the input we sent.


As mentioned above, the main limitation here is that you need to manually unpause the Workflow. It would be nice if there was a way for the Zaqar message to automatically do this.

Polling for messages in the Workflow would be quite easy, with a retry loop and Mistral's continue-on. However, that would be quite resource intensive. If you wanted to do this, a Workflow task like this would probably do the trick.

    action: zaqar.queue_pop
      queue_name: <% $.input_queue %>
    timeout: 14400
      delay: 15
      count: <% $.timeout / 15 %>
      continue-on: <% len(task(wait_for_message).result) > 0 %>

The other limitation is that this Workflow now requires a specific interaction pattern that isn't obvious and documenting it might be a little tricky. However, I think the flexible execution it provides might be worthwhile in some cases.

by Dougal Matthews at January 31, 2017 07:40 AM

January 25, 2017

Dan Prince

Docker Puppet

Today TripleO leverages Puppet to help configure and manage the deployment of OpenStack services. As we move towards using Docker one of the big questions people have is how will we generate config files for those containers. We'd like to continue to make use of our mature configuration interfaces (Heat parameters, Hieradata overrides, Puppet modules) to allow our operators to seamlessly take the step towards a fully containerized deployment.

With the recently added composable service we've got everything we need. This is how we do it...

Install puppet into our base container image

Turns out the first thing you need of you want to generate config files with Puppet is well... puppet. TripleO uses containers from the Kolla project and by default they do not install Puppet. In the past TripleO uses an 'agent container' to manage the puppet installation requirements. This worked okay for the compute role (a very minimal set of services) but doesn't work as nicely for the broader set of OpenStack services because packages need to be pre-installed into the 'agent' container in order for config file generation to work correctly (puppet overlays the default config files in many cases). Installing packages for all of OpenStack and its requirements into the agent container isn't ideal.

Enter TripleO composable services (thanks Newton!). TripleO now supports composability and Kolla typically has individual containers for each service so it turns out the best way to generate config files for a specific service is to use the container for the service itself. We do this in two separate runs of a container: one to create config files, and the second one to launch the service (bind mounting/copying in the configs). It works really well.

But we still have the issue of how do we get puppet into all of our Kolla containers. We were happy to discover that Kolla supports a template-overrides mechanism (A jinja template) that allows you to customize how containers are built. This is how you can use that mechanism to add puppet into the Centos base image used for all the OpenStack docker containers generated by Kolla build scripts.

$ cat template-overrides.j2
{% extends parent_template %}
{% set base_centos_binary_packages_append = ['puppet'] %}

kolla-build --base centos --template-override template-overrides.j2

Control the Puppet catalog

A puppet manifest in TripleO can do a lot of things like installing packages, configuring files, starting a service, etc. For containers we only want to generate the config files. Furthermore we'd like to do this without having to change our puppet modules.

One mechanism we use is the --tags option for 'puppet apply'. This option allows you to specify which resources within a given puppet manifest (or catalog) should be executed. It works really nicely to allow you to select what you want out of a puppet catalog.

An example of this is listed below where we have a manifest to create a '/tmp/foo' file. When we run the manifest with the 'package' tag (telling it to only install packages) it does nothing at all.

$ cat test.pp 
file { '/tmp/foo':
  content => 'bar',
$ puppet apply --tags package test.pp
Notice: Compiled catalog for undercloud.localhost in environment production in 0.10 seconds
Notice: Applied catalog in 0.02 seconds
$ cat /tmp/foo
cat: /tmp/foo: No such file or directory

When --tags doesn't work

The --tags option of 'puppet apply' doesn't always give us the behavior we are after which is to generate only config files. Some puppet modules have custom resources with providers that can execute commands anyway. This might be a mysql query or an openstackclient command to create a keystone endpoint. Remember here that we are trying to re-use puppet modules from our baremetal configuration and these resources are expected to be in our manifests... we just don't want them to run at the time we are generating config files. So we need an alternative mechanism to suppress (noop out) these offending resources.

To do this we've started using a custom built noop_resource function that exists in puppet-tripleo. This function dynamically configures a default provider for the named resource. For mysql this ends up looking like this:

['Mysql_datadir', 'Mysql_user', 'Mysql_database', 'Mysql_grant', 'Mysql_plugin'].each |String $val| { noop_resource($val) }

Running a puppet manifest with this at the top will noop out any of the named resource types and they won't execute. Thus allowing puppet apply to complete and finish generating the config files within the specified manifest.

The good news is most of our services don't require the noop_resource in order to generate config files cleanly. But for those that do the interface allows us to effectively disable the resources we don't want to execute.

Putting it all together:

Bringing everything together in tripleo-heat-templates to create one container configuration interface that will allow us to configurably generate per-service config files. It looks like this:

  • manifest: the puppet manifest to use to generate config files (Thanks to composable services this is now per service!)
  • puppet_tags: the puppet tags to execute within this manifest
  • config_image: the docker image to use to generate config files. Generally we use the same image as the service itself.
  • config_volume: where to output the resulting config tree (includes /etc/ and some other directories).

And then we've created a custom tool to drive this per-service configuration called The tool supports using the information above in a Json file format drive generation of the config files in a single action.

It ends up working like this:

Video demo: Docker Puppet

And thats it. Our config interfaces are intact. We generate the config files we need. And we get to carry on with our efforts to deploy with containers.


by Dan Prince at January 25, 2017 02:00 PM

Last updated: August 19, 2018 05:10 AM

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