How to have the .github workflows sharable or reusable

Question

We have a repo that contains a bunch of workflows that we want to share amongst all of our dev repositories.

github-common-workflows repository:
  workflows/build.yml
  workflows/test.yml

Is there a way to import the repo above as a submodule or subtree within our dev repos, e.g.:

dev-repo repository:
  .github/<point to the github-common-workflows repo>

BECAUSE - when using submodules, github actions will not recognize any workflows at all Hence no github workflow will be triggered (e.g. upon push)

Any ideas how to achieve a single place that contains all the workflows and shared amongst all repos?

Answer 1

A possible solution for private repos is to upload the shareable repo as an artifact, e.g. a compressed archive and host it somewhere accessible. When the caller workflow kicks in, simply download the archive and extract it into the current context.

E.g.:

Assuming $archive-url =https://example.org/shareable-workflow.tar: workflow.yml

    jobs:
      - name: Checkout context repo
         run: actions/checkout@v2

      - name: Download the shareable workflow
         run: curl $archive-url | tar xzf -  

      - uses: ./workflow.yml

Answer 2

Having .github/workflows as a submodule won't work since github can't see the workflows defined in the target repo.

Solution:

Workflows can be defined in a common separate workflows repo and can be reused by multiple repositories, using the caller/called reusable workflow syntax (workflow_call) official docs can be found here:

https://docs.github.com/en/actions/using-workflows/reusing-workflows

Bear in mind, as for Feb.2022 Reusable workflows are not available for github enterprise (unfortunately)