Define slave_base_tag_ref variable in Makefile.work containing
specific base image tag to use, rather than always defaulting
to :latest.
Add an ARG command before FROM statement in Dockerfile.user
for sonic-slave and sonic-slave-stretch. ARG variable defaults
to latest if slave_base_tag_ref not specified in Makefile.work.
The presumption to always refer to the :latest tagged Docker base
image when creating the user image causes problems in a shared
build server environment, where the most recently created base
image (i.e. the current :latest tag) may not be compatible with
the current build. For example, different users working in
different branches may all be sharing the same build server.
Signed-off-by: Greg Paussa greg.paussa@broadcom.com
- What I did
Added a DOCKER_AVOID_BASE_TAG_LATEST build option to rules/config that forces the Docker user image creation to refer to its base image by a specific tag rather than rely on the :latest tag. This is needed in a shared build server environment where builds from different developers and/or different SONiC branches all converge on the same Docker daemon instance running on the build server. The :latest tag is always assigned to the most recent base image built, which might not correspond to the base image needed for a particular build, thus causing various build errors that mostly manifest as missing Debian packages or package version mismatches.
NOTE TO REVIEWERS: This PR relies on Docker support of "ARG before FROM," which was first introduced in Docker version 17.05.1-ce. Although there is no mention of a minimum required Docker version for the build server in the SONiC Building Guide pages, please consider whether it is reasonable to assume that Docker 17.05.1-ce or later must be used for SONiC build hosts before approving this PR.
- How I did it
Added an ARG before the FROM statement at the top of the sonic-slave/Dockerfile.user and sonic-slave-stretch/Dockerfile.user files. The ARG variable defaults to latest, but can be overridden in Makefile.work to reference the SLAVE_BASE_TAG so that it refers to the specific, matching base image for the build. This override is activated by un-commenting the DOCKER_AVOID_BASE_TAG_LATEST = y line in rules/config.
