intel-media-ffmpeg/docs/developing.md

Developing

The Dockerfile itself is constructed from re-usable snippets, located in the templates/ directory, and can be regenerated by running:

scripts/build-dockerfile

The above script uses environment substitution to stamp version information within the created Dockerfile. The files which declare the environment variables are in SOLUTION and MANIFEST.

After joining the template/* pieces together, the file Dockerfile.solution is then added to the Dockerfile with environment substitution.

SOLUTION

Solution specific definitions:

CONTAINER_IMAGE is used as the container tag name
OS_DISTRO       is used as the base OS distribution. Possible values: ubuntu
OS_RELEASE      is used as the OS version. Possible values: eoan, eoan

MANIFEST

The version of MANIFEST is created by the set of Agama packages from the Agama repository and name-mangling them to be a VERSION declaration:

For example:

libgl1-mesa-glx_19.0.1-agama-109_amd64.deb

is changed to:

LIBGL1_MESA_GLX_VERSION=19.0.1-agama-109

This allows the Dockerfile templates version pin Agama packages:

  RUN apt-get install -y libgl1-mesa-glx=$LIBGL1_MESA_GLX_VERSION

The scripts/build-dockerfile loads MANIFEST, which defines LIBGL1_MESA_GLX_VERSION. That is then subsituted for the version in the above Dockerfile snippet when being placed into the main Dockerfile.

Tagging

If the build succeeds, we want to be able to tag the git project as well as corresponding Docker images with the appropriate Agama tag:

. MANIFEST ; git tag -f agama-${AGAMA_VERSION}