Question

You are authoring a Docker container action. Inside the entrypoint script (a bash script that runs as the container's ENTRYPOINT), you need to expose a value called build-id so that subsequent steps in the consuming workflow can reference it via steps.<id>.outputs.build-id. Which mechanism inside the container script correctly sets this step output?

Accepted Answer

Echo the value to the file referenced by the GITHUB_OUTPUT environment variable, e.g. echo "build-id=$VALUE" >> "$GITHUB_OUTPUT"

Answer

Print echo "::set-env name=build-id::$VALUE" to stdout so the runner captures it as an output

Answer

Write the value to the file referenced by GITHUB_ENV, e.g. echo "build-id=$VALUE" >> "$GITHUB_ENV"

Answer

Declare build-id under the outputs: key in the Dockerfile so the runner maps it automatically