Now that Docker image building is called from Python, we can start to
do advanced stuff with it.
With this commit, we switch from building Docker images directly from
the source directory ("the Docker way") to using our custom Docker image
build contexts.
The main advantage of this is that locally-built Docker images can now
use our custom Dockerfile syntax to include extra files in the build
context!
The code for building a Docker image from a context has been extracted
to its own standalone function. I have nefarious plans for this in the
future, such as the ability to override the FROM syntax to specify
URLs of images. This would allow us to host base images on our own
server, which removes a dependency on Docker Hub and improves
determinism, since images on Docker Hub change all the time.
MozReview-Commit-ID: 5lTdV8yEHkc
build.sh had been reduced to invoking `docker`. We move that invocation
to Python and remove build.sh. Long live build.sh!
MozReview-Commit-ID: FQBDJv4HSaU
We already had code for resolving the image registry and tag. We
refactored it slightly to be more useful then changed build.sh to
accept the tag as an argument.
At this point, build.sh is basically a wrapper around `docker`. But
there's a special case for executing custom "build.sh" files we
need to eliminate first...
MozReview-Commit-ID: A9HVvxgCdG2
Now that we have a mach command and Python code for doing Docker image
building, we can start moving code from build.sh to Python.
We start with searching for and validating the `docker` binary works.
MozReview-Commit-ID: 2DCc3b8UyZ3
Docker image building will soon need to use Python in order to produce
the image build context archive.
As the first step towards this, we introduce a Python function that
calls out to build.sh. We also implement a mach command that calls it
so we can test the functionality.
I'm not keen about introducing a new mach command. I'd prefer to have
a sub-command instead. I'm not sure what all uses
`mach taskcluster-load-image`. Perhaps we could make a `taskcluster`
top-level command. Or perhaps we could fold these image commands into
`mach taskgraph`? Either way, the mach side of this isn't terribly
important to the commit series: most of the code will live inside a
Python module outside of mach.
MozReview-Commit-ID: AI8p6H4psNh
This restores order to only having a single hash for a context
directory.
Using a tempfile here is a bit unfortunate. It can be optimized later,
if needed.
MozReview-Commit-ID: LMNsvt3fDYx
