Building Custom Tower Images for OpenShift
Let's build and deploy a modified Ansible Tower container with extra Python libraries.
You'll need to do this, for instance, if you ever try to use the
gcp_* modules for talking to GCE: Ansible will complain about
missing the google-auth Python library. You shouldn't just pip install it on your running container, so let's build a new Tower
image based on the old one, but with a new Python virtual environment
containing our missing Python libraries.
First, create a Dockerfile that looks like this:
FROM registry.access.redhat.com/ansible-tower-34/ansible-tower:latest
USER root
RUN mkdir -p /var/lib/awx/venv/gce
RUN virtualenv --system-site-packages /var/lib/awx/venv/gce
RUN umask 0022 \
&& cp -a /var/lib/awx/venv/ansible/lib64/python2.7/site-packages/* \
/var/lib/awx/venv/gce/lib64/python2.7/site-packages/ \
&& sh -c ". /var/lib/awx/venv/gce/bin/activate ; pip install google_auth;"
This creates a new Python virtual environment called gce that has
the google_auth module installed.
And since we're using OpenShift, let's create ImageStream and BuildConfig objects based on these files:
ImageStream:
apiVersion: v1
kind: ImageStream
metadata:
labels:
app: labdroid-tower
name: labdroid-tower
spec: {}
BuildConfig:
apiVersion: v1
items:
- apiVersion: v1
kind: BuildConfig
metadata:
annotations:
labels:
app: "labdroid-tower"
name: "labdroid-tower"
spec:
output:
to:
kind: "ImageStreamTag"
name: "labdroid-tower:latest"
resources: {}
source:
git:
ref: master
uri: https://gogs-labdroid.apps.home.labdroid.net/green/labdroid-tower.git
contextDir:
type: Git
strategy:
dockerStrategy:
dockerfilePath: Dockerfile
from:
kind: DockerImage
name: ansible-tower-34/ansible-tower
forcePull: true
type: Docker
kind: List
metadata: {}
Be sure to change the uri up there to point at your git repo
containing the Dockerfile. You'll probably want to change
labdroid-tower to something else as well. This will be the name of
your new container image.
Log into your Tower project on OpenShift, then create the objects and start the build like so:
$ oc create -f ImageStream.yml
$ oc create -f BuildConfig.yml
$ oc start-build labdroid-tower --follow
Now you'll have a new Tower image called labdroid-tower:latest. To
deploy it, you need to change these variables in group_vars/all for
the Tower OpenShift installer playbook:
kubernetes_web_image: docker-registry.default.svc:5000/tower/labdroid-tower
kubernetes_task_image: docker-registry.default.svc:5000/tower/labdroid-tower
kubernetes_task_version: 'latest'
kubernetes_web_version: 'latest'
Now run the Tower installer and the old Tower containers will be replaced with your new one.
In this case I needed the google-auth library on the target machine
for my playbook (which happens to be the Tower container), so I force
it to run in the virtual environment containing this library like so:
- name: Use the GCE API to do some things
hosts: localhost
gather_facts: no
vars:
ansible_python_interpreter: "/var/lib/awx/venv/gce/bin/python"
That's it!
Happy hacking,
AG
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