Building containers on OBS

20 Apr 2020

Building containers on OBS

My friend showed me how to build containers in OBS, the opensuse build service. It makes it really quite nice, as the service can parse your dockerfile, and automatically trigger rebuilds when any package dependency in the chain requires a rebuild.

The simplest way is to have a seperate project for your containers to make the repository setup a little easier.

When you edit the project metadata, if the project doesn't already exist, a new one is created. So we can start by filling out the template from the command:

osc meta prj -e home:firstyear:containers

This will give you a template: We need to add some repository lines:

<project name="home:firstyear:apps">
  <title>Containers Demo</title>
  <description>Containers Demo</description>
  <person userid="firstyear" role="bugowner"/>
  <person userid="firstyear" role="maintainer"/>
  <build>
    <enable/>
  </build>
  <publish>
    <enable/>
  </publish>
  <debuginfo>
    <enable/>
  </debuginfo>
  <!-- this repository -->
  <repository name="containers">
    <path project="openSUSE:Templates:Images:Tumbleweed" repository="containers"/>
    <arch>x86_64</arch>
  </repository>
</project>

Remember, to set the publist to "enable" if you want the docker images you build to be pushed to the registry!

Now that that's done, we can check out the project, and create a new container package within.

osc co home:firstyear:containers
cd home:firstyear:containers
osc mkpac mycontainer

Now in the mycontainer folder you can start to build a container. Add your dockerfile:

#!BuildTag: mycontainer
#
# docker pull registry.opensuse.org/home/firstyear/apps/containers/mycontainer:latest
#                                   ^projectname        ^repos     ^ build tag
FROM opensuse/tumbleweed:latest

#
# only one zypper ar command per line. only repositories inside the OBS are allowed
#
RUN zypper ar http://download.opensuse.org/repositories/home:firstyear:apps/openSUSE_Tumbleweed/ "home:firstyear:apps"
RUN zypper mr -p 97 "home:firstyear:apps"
RUN zypper --gpg-auto-import-keys ref
RUN zypper install -y vim-data vim python3-ipython shadow python3-praw
# Then the rest of your container as per usual ...

Then to finish up, you can commit this:

osc add Dockerfile
osc ci
osc results