Support devcontainer.json option 'buildArgs'

[jeffreyjam]

Currently in devcontainer.json it's possible to pass a list of arguments to docker run with the runArgs option, but there's no corresponding buildArgs option to pass a list of arguments to docker build.

For my particular case I'm looking to pass the --pull argument to docker build so I can keep my devcontainers up to date by rebuilding them and don't have to bump versions by hand.

It looks like some people over in #2200 are looking for the ability to pass the --no-cache option, and I bet there are other options people would like to pass too.

The docker build options --target and --build-arg were added as a part of #46 last year but it stopped short of adding the ability to pass arbitrary options, which would be really convenient.

There exists the similar-sounding build.args option in devcontainer.json right now, so it might be better to use a different name than buildArgs, for example build.options or build.cliArgs.

[felipecrs]

buildArgs would be very helpful, despite I think --pull should be along with the default docker build command for the devcontainer.

[eitsupi]

+1

If we want to use --add-host in a container, we can write it in runArgs, but if we want to use it during build, there is no way to set it.

"runArgs": ["--add-host=host.docker.internal:host-gateway"]

[felipecrs]

This seems to be a duplicate of #3545.

[pgs31]

+1 I'd love to be able to use this so I can use docker build --ssh. I haven't been able to find a good way to get my private key into the docker build stage other than pasting it into devcontainer.json as a docker build arg.

[Chuxel]

Doing some dupe cleanup. Closing as dupe of #3545