Corbos SCM - OBS service

An Open Build Service (OBS) service to fetch Debian packages sources. The service can be used for Debian/Ubuntu based packages and utilizes the ubuntu-dev-tools from a container. Calling from a container allows to use the Ubuntu devtools toolchain independently from the host system as long as the host supports the podman container engine

As an example, the following steps are needed to build the curl package from Debian for Ubuntu(20.10) in OBS.

1. Install corbos_scm service

   Install the service provided at:

   • https://build.opensuse.org/package/show/home:marcus.schaefer/python-corbos_scm

   locally and on the remote backend server of your build service

   Warning:

   The example below can only work if the corbos_scm service was installed on the backend server of your build service.

2. Create a package in OBS

   osc mkpac curl

3. Create the _service file and add it

   cd curl
   touch _service
   osc add _service

4. Add the following contents to the _service file

   <services>
     <service name="corbos_scm">
       <param name="registry">registry.example.com</param>
       <param name="container">ubdevtools:latest</param>
       <param name="package">curl</param>
     </service>
   </services>

5. Commit the service setup

   osc ci

6. Add Ubuntu repository to allow dependency resolving and the package build

   osc meta -e prj

   Add a repo definition which allows to resolve the required build dependencies. The following is just an example matching repos as they exist in the public build service provided by SUSE.

   Note:

   Be aware that the following repo definiton just serves as an example and will most likely not be available in the exact same way on a custom OBS server.

   <repository name="xUbuntu_21.04">
     <path project="Ubuntu:21.04" repository="universe"/>
     <arch>x86_64</arch>
   </repository>

Container Setup

If there is no container with ubuntu-dev-tools available, the following KIWI description can be used to build one

<image schemaversion="7.4" name="ubuntu-dev-tools">
  <description type="system">
    <author>Marcus Schäfer</author>
    <contact>marcus.schaefer@gmail.com</contact>
    <specification>Runtime container ubuntu dev tools</specification>
  </description>
  <preferences>
    <version>1.0.1</version>
    <packagemanager>apt</packagemanager>
    <type image="docker">
      <containerconfig name="ubdevtools"/>
    </type>
  </preferences>
  <repository type="apt-deb" alias="kiwi-next-generation" priority="1" repository_gpgcheck="false">
    <source path="obs://Virtualization:Appliances:Builder/xUbuntu_21.04"/>
  </repository>
  <repository type="apt-deb" alias="Ubuntu-Hirsute-Universe" distribution="hirsute" components="main multiverse restricted universe" repository_gpgcheck="false">
    <source path="obs://Ubuntu:21.04/universe"/>
  </repository>
  <repository type="apt-deb" alias="Ubuntu-Hirsute" distribution="hirsute" components="main multiverse restricted universe" repository_gpgcheck="false">
    <source path="obs://Ubuntu:21.04/standard"/>
  </repository>
  <packages type="image">
    <package name="ubuntu-dev-tools"/>
    <package name="mawk"/>
  </packages>
  <packages type="bootstrap"/>
</image>

Behind the Scenes

The corbos_scm service is very simple. It uses the tooling provided by the ubuntu-dev-tools to create the source files such that OBS can build the package.

On the local system the service can be tested with:

osc service localrun

This call creates the mentioned data locally. For the service to be effective on the remote backend of OBS, it's required to install it there. This is because obs creates a command call from the information provided in the _service file and issues that command on its remote backend.