I am implementing my GitHub Action workflow file which is supposed to update my docker images hosted on GCR, and then log into my GCE instance to pull the newly updated images with docker compose.
The problem is I am getting an error at docker compose pull :

err: frontend Error Head "https://europe-west9-docker.pkg.dev/v2/***/registry/frontend/manifests/latest": unauthorized: authentication failed

If I ssh into my GCE instance, and run : sudo gcloud auth login, follow instructions to login and then run the workflow file, it succeeds to pull the images.

What changes can I make to my git actions file so that I don’t need to auth login in my VM for it to pull my images ?

Here is what my git action workflow file looks like:

name: Deploy App on Dev Env

on:
  push:
    branches:
      - 'develop'

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:

    - name: Checkout code
      uses: actions/checkout@v2

    - name: Set up Google Cloud SDK (service with admin rights for GCR)
      uses: google-github-actions/setup-gcloud@v0
      with:
        project_id: ${{ secrets.GOOGLE_PROJECT }}
        service_account_key: ${{ secrets.GOOGLE_APPLICATION_CREDENTIALS }}
        export_default_credentials: true

    - name: Authenticate Docker with GCR
      run: |
        gcloud auth configure-docker europe-west9-docker.pkg.dev

    - name: Build and push backend Docker image
      env:
        GOOGLE_PROJECT: ${{ secrets.GOOGLE_PROJECT }}
      run: |
        docker build -f Dockerfile.backend -t europe-west9-docker.pkg.dev/$GOOGLE_PROJECT/registry/backend:latest .
        docker push europe-west9-docker.pkg.dev/$GOOGLE_PROJECT/registry/backend:latest

    - name: Build and push frontend Docker image
      env:
        GOOGLE_PROJECT: ${{ secrets.GOOGLE_PROJECT }}
      run: |
        docker build -f frontend/Dockerfile -t europe-west9-docker.pkg.dev/$GOOGLE_PROJECT/registry/frontend:latest frontend/
        docker push europe-west9-docker.pkg.dev/$GOOGLE_PROJECT/registry/frontend:latest

    - name: Deploy to GCP VM
      uses: appleboy/[email protected]
      with:
        host: ${{ secrets.GCP_VM_IP }}
        username: ${{ secrets.GCP_VM_USER }}
        key: ${{ secrets.GCP_VM_SSH_KEY }}
        script: |
          sudo docker compose pull
          sudo docker compose up -d --remove-orphans
          sudo docker image prune -a -f

I’ve been looking for ways to authenticate to my instance through git actions, but couldn’t find one that works.