Support Build & Setup Environment Variables

[metaskills]

In my case I have a postCreateCommand that clones another organization repo. This works great under Codespaces but is hanging when using this project. I think what I see is that 🏃 start container will stop here.

Cloning into '/workspaces/mysharedrepo'...
Username for 'https://github.com/':

And never move from that spot. The lifecycle script is doing something like this.

git clone "https://${GITHUB_TOKEN}@github.com/myorg/mysharedrepo.git" /workspaces/mysharedrepo
cd /workspaces/mysharedrepo

Any recommendations to get that working?

[metaskills]

Would it make sense to have the env: variables be accessible to both the build and start stages? That might help here.

[metaskills]

FWIW, I would be happy if there was ANY environment variable during the build / start process so I could make some runtime decisions?

[Oblynx]

Hi! I wanted to request exactly the same feature.

I would like to run a postCreateCommand that pulls a private repo. I specify the secrets as environment variables, but they aren't picked up at the build stage. When I move the step that pulls the private repo to the runCmd, it works. Therefore, the only issue is that the environment variables specified in env aren't passed to the build phase.

[joshspicer]

Hey! This proposal makes sense to me. @stuartleeks I suspect you'll agree this is OK, but curious if there's any thoughts you have counter?

[stuartleeks]

I was wondering whether there would be any scenarios where we would want to set the build environment variables independently of the runtime ones.

E.g. would we want to have buildEnv and env, or just have env that is passed to both?

[Oblynx]

You can start with passing env to both. Then if an issue is reported with this behavior, we can split it up.

[metaskills]

You can start with passing env to both. Then if an issue is reported with this behavior, we can split it up.

Agreed here too. Thank you.

[Oblynx]

Hello! Just bumping this issue, is it being tracked/planned?

[stuartleeks]

I've was looking at adding support for this to the action, and was a little confused by the results of my testing for a while so thought I'd drop a comment here.

There's a PR to improve support for this (#211) but depending on how your devcontainer.json is set up, you may be able to make this work already.

To do this, you need to have the remoteEnv in your devcontainer.json referencing a value from localEnv:

	 "remoteEnv": {
		"YOUR_ENV" : "${localEnv:YOUR_ENV}"
	}

This instructs the devcontainer CLI to set the remote env in the container based on the localEnv context.

The localEnv context can be set using the env property at the step level (i.e. not nested under the with block):

      - name: Build and run Dev Container task
        uses: devcontainers/ci@v0.2
        env:
          YOUR_ENV_VAR: some_value
        with:
          runCmd: |
            make the-thing

#211 will add update the action so that env vars set in the env under the with block are passed to the container. This will provide a way to set container env vars without needing to have it set in devcontainer.json.

I'll raise an issue to add examples of this to the docs.

[metaskills]

I'm trying this out now and still can not figure out how to use an environment variable when the devcontainer is being built. I've read the docs in the PR work @stuartleeks did but still can't figure it out. Is the env only available to runCmd?