Push to GCR GitHub Action

An action that builds docker image and pushes to Google Cloud Registry and Google Artifact Registry.

This action can be used to perform on every git push or every tag creation.

Inputs

gcloud_service_key

The service account key of google cloud. The JSON file can be encoded in base64 or in plain text.

Prior to version 4.1 - This field is required.

From version 5 - This field is optional when you are using workload identity with step-security/google-github-auth

registry

The registry where the image should be pushed. Default gcr.io.

project_id

The project id. This field is required.

image_name

The image name. This field is required.

image_tag

The tag for the image. To create multiple tags of the same image, provide a comma (,) separated tag name (e.g. v2.1,v2,latest).

Default: latest.

To use the pushed Tag Name as image tag, see the example.

dockerfile

The image building Dockerfile. If the context is not the root of the repository, Dockerfile from the context folder will be used.

Default: ./Dockerfile.

context

The docker build context. Default: .

target

If you use a multi-stage build and want to stop building at a certain image, you can use this field. The default value is empty.

build_args

Pass a list of env vars as build-args for docker-build, separated by commas. ie: HOST=db.default.svc.cluster.local:5432,USERNAME=db_user

push_only

If you want to skip the build step and just push the image built by any previous step, use this option. The default for this is false.

Permissions

The service key you provided must have the Storage Admin permission to push the image to GCR. It is possible to use a lower access level Storage Object Admin, but it will work only if the registry is already created. You must also add the Storage Legacy Bucket Reader permission to the artifacts.<project id>.appspot.com bucket for the given service account.

Reference 1

Reference 2

To create service key/account visit here

Workload Identity Federation

If you want to use Workload Identity Federation, follow the steps from here to set up Workload Identity Federation

Example usage

name: Push to GCR GitHub Action
on: [push]
jobs:
  build-and-push-to-gcr:
    runs-on: ubuntu-latest
    permissions:
      contents: 'read'
      id-token: 'write'
    steps:      
      - uses: actions/checkout@v6
      - name: Authenticate to Google Cloud
        id: auth
        uses: step-security/google-github-auth@v3
        with:
          workload_identity_provider: projects/123123123/locations/global/workloadIdentityPools/the-workload-pool/providers/the-provider
          service_account: artifact-registry-writer@<PROJECT_ID>.iam.gserviceaccount.com
      - uses: step-security/push-to-gcr-github-action@v5
        with:
          # gcloud_service_key: ${{ secrets.GCLOUD_SERVICE_KEY }} # can be base64 encoded or plain text || not needed if you use step-security/google-github-auth
          registry: gcr.io
          project_id: my-awesome-project
          image_name: backend
          image_tag: latest,v1
          dockerfile: ./docker/Dockerfile.prod
          context: ./docker

Example