openstack/tripleo-docs
Code Issues Proposed changes

Add a short explanation on how to update a container for code fixes

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We need a short howto to explain to folks how to test code fixes that
affect the container itself.

Co-Authored-By: Ian Pilcher <ipilcher@redhat.com>

Change-Id: I0ac7901914bb6340e1552b19d16684981ce6cd05
This commit is contained in:
Michele Baldessari 2017-09-11 22:20:48 +02:00
parent 4592ed06f9
commit d1e2a22b01
1 changed files with 46 additions and 0 deletions
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46
doc/source/install/containers_deployment/tips_tricks.rst
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@ -228,6 +228,52 @@ run for docker-puppet might look like::
SHOW_DIFF=True PROCESS_COUNT=1 CONFIG=glance_api.json ./docker-puppet.py
Testing a code fix in a container
---------------------------------
Let's assume that we need to test a code patch or an updated package in a
container. We will look at a few steps that can be taken to test a fix
in a container on an existing deployment.
For example let's update packages for the mariadb container::
(undercloud) [stack@undercloud ~]$ docker images | grep mariadb
192.168.24.1:8787/tripleoupstream/centos-binary-mariadb latest 035a8237c376 2 weeks ago 723.5 MB
So docker image `035a8237c376` is the one we need to base our work on. Since
docker images are supposed to be immutable we will base our work off of
`035a8237c376` and create a new one::
mkdir -p galera-workaround
cat > galera-workaround/Dockerfile <<EOF
FROM 192.168.24.1:8787/tripleoupstream/centos-binary-mariadb:latest
USER root
RUN yum-config-manager --add-repo http://people.redhat.com/mbaldess/rpms/container-repo/pacemaker-bundle.repo && yum clean all && rm -rf /var/cache/yum
RUN yum update -y pacemaker pacemaker-remote pcs libqb resource-agents && yum clean all && rm -rf /var/cache/yum
USER mysql
EOF
To determine which user is the default one being used in a container you can run `docker run -it 035a8237c376 whoami`.
Then we build the new image and tag it with `:workaround1`::
docker build --rm -t 192.168.24.1:8787/tripleoupstream/centos-binary-mariadb:workaround1 ~/galera-workaround
Then we push it in our docker registry on the undercloud::
docker push 192.168.24.1:8787/tripleoupstream/centos-binary-mariadb:workaround1
At this stage we can either point THT to use
`192.168.24.1:8787/tripleoupstream/centos-binary-mariadb:workaround1` as the
container image by tweaking the necessary environment files and we redeploy the overcloud.
If we only want to test a tweaked image, the following steps can be used:
First, determine if the containers are managed by pacemaker (those will typically have a `:pcmklatest` tag) or by paunch.
For the paunch-managed containers see `Debugging with Paunch`_.
For the pacemaker-managed containers you can (best done on your staging env, as it might be an invasive operation) do the following::
1. `pcs cluster cib cib.xml`
2. Edit the cib.xml with the changes around the bundle you are tweaking
3. `pcs cluster cib-push --config cib.xml`
Testing in CI
-------------