Feature Request - Ability to reference secrets and environments variables

This is more of a feature request so I don’t know if this forum is the best place for it, but still.

Recently, support for private registers was announced for service containers (https://github.blog/changelog/2020-09-24-github-actions-private-registry-support-for-job-and-service-containers/).

Even before that functionality was available, we were already using ecr credential helper Docker workaround which works for self hosted runners.

Currently the problem / limitation with the service containers is that you can’t reference environment variables or secrets for the image attribute value.

For example:

        image: ${{ secrets.PRIVATE_REGISTRY }}/${{ needs.step1.outputs.DOCKER_IMAGE }}

        image: ${{ env.PRIVATE_REGISTRY }} /${{ needs.step1.outputs.DOCKER_IMAGE }}

Neither of those approaches works and returns an error.

The workflow is not valid. .github/workflows/main.yaml (Line: 309, Col: 16): Unrecognized named-value: 'env'. Located at position 1 within expression: env.DOCKER_IMAGE

(I also can’t put registry name into published DOCKER_IMAGE output variable since it contains a secret so it won’t be published - I could perhaps get it to work via some hacks / intermediate action which would unmask that value but that seems overly complicated for such a simple thing…).

I assume this limitation is related to context variable life cycle and scoping.

I don’t see any reason why we shouldn’t at least be able to access secrets in that context.


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