Fetch private GitHub dependency in GitHub Action with Access Token

Questions & Help Questions
2

Got it.

For anyone wondering how to pull private repositories during mix.compile using the docker-build-push GitHub action:

Create Access Token

Create a Personal Access Token (Sign in to GitHub · GitHub ; Navigation: Profile > Settings > Developer Settings > Personal Access Tokens > Fine Grained Tokens). It should be able to read repositories you have access to.

Consider using a “machine user”, as in a normal user account that was created just for the purpose of holding your tokens, if you are an organisation.

Add token as Secret

Create a secret in your organisation or repository, e.g. CI_ACCESS_TOKEN. (Repo: Settings > Secrets and Variables > Actions). Put in your previously created token. I made the mistake of adding it to an “environment” by accident at first and wondered why it was not working as intended.

Set up workflow file

In your github workflow file:

   - name: Build and push
     uses: docker/build-push-action@v5
     with:
       context: .
       file: ./Dockerfile
       push: true
       tags: ...
       secrets: |
         GIT_AUTH_TOKEN=${{ secrets.CI_ACCESS_TOKEN }}

Dockerfile

in your Dockefile, grab the secret, configure git, get the deps:

RUN --mount=type=secret,id=GIT_AUTH_TOKEN \
 GIT_AUTH_TOKEN=$(cat /run/secrets/GIT_AUTH_TOKEN) \
 && git config --global "url.https://${GIT_AUTH_TOKEN}@github.com.insteadof" "https://github.com" \
 && mix deps.get --only $MIX_ENV