Handle GITHUB_OUTPUT

[stuartleeks]

GitHub actions are deprecating the previous set-output approach for setting outputs in favour of echoing to GITHUB_OUTPUT (link) as flagged by @stephenandary in #180.

When run inside a dev container, the GITHUB_OUTPUT location is not accessible (even if the environment variable is set).

Proposed approach to handling this:

• mount the host's GITHUB_OUTPUT location to /mnt/github/output inside the dev container
• set the GITHUB_OUTPUT environment variable in the container to /mnt/github/output

This could be done automatically so that this just works as expected for users of the CI action.

Additionally, this approach could be adopted for GITHUB_OUTPUT, GITHUB_STATE, GITHUB_ENV, GITHUB_STEP_SUMMARY, and GITHUB_PATH

[stuartleeks]

This would require an update to devcontainers/cli (link)

[andar1an]

Can the CLI handle multiple mount points already? Asking based on language in the description here: devContainersSpecCLI.ts#L112

[stuartleeks]

Yes, you're right!

[andar1an]

Thank goodness haha. I like when things require less work! 😆

[joseviccruz]

+1!
I really need this feature ASAP

[joseviccruz]

Hi everyone, any updates here?

[stuartleeks]

I believe that @stephenandary is planning to handle this in #219

[stuartleeks]

Closed by #219