Push-to-registry is a GitHub Action for pushing a container image to an image registry, such as Dockerhub, quay.io, the GitHub Container Registry, or an OpenShift integrated registry.

This action only runs on Linux, as it uses podman to perform the push. GitHub's Ubuntu action runners come with Podman preinstalled. If you are not using those runners, you must first install Podman.

You can log in to your container registry for the entire job using the podman-login action. Otherwise, use the username and password inputs to log in for this step.

Refer to the podman push documentation for more information.

The push-to-registry image and tag input work very similarly to buildah-build.

However, when using push-to-registry when the tags input are not fully qualified, the registry input must also be set.

So, for push-to-registry the options are as follows:

Option 1: Provide registry, image, and tags inputs. The image(s) will be pushed to ${registry}/${image}:${tag}.

For example:

registry: quay.io/my-namespace
image: my-image
tags: v1 v1.0.0

will push the image tags: quay.io/my-namespace/my-image:v1 and quay.io/my-namespace/my-image:v1.0.0.

Option 2: Provide only the tags input, including the fully qualified image name in each tag. In this case, the registry and image inputs are ignored.

For example:

# 'registry' and 'image' inputs are not set
tags: quay.io/my-namespace/my-image:v1 quay.io/my-namespace/my-image:v1.0.0

will push the image tags: quay.io/my-namespace/my-image:v1 and quay.io/my-namespace/my-image:v1.0.0.

If the tags input does not have image names in the ${registry}/${name}:${tag} form, then the registry and image inputs must be set.

digest: The pushed image digest, as written to the digestfile.
For example:

sha256:66ce924069ec4181725d15aa27f34afbaf082f434f448dc07a42daa3305cdab3

For multiple tags, the digest is the same.

registry-paths: A JSON array of registry paths to which the tag(s) were pushed.

For example:

[ "quay.io/username/spring-image:v1", "quay.io/username/spring-image:latest" ]

registry-path: The first element of registry-paths, as a string.

The example below shows how the push-to-registry action can be used to push an image created by the buildah-build action.

name: Build and Push Image
on: [ push ]

jobs:
  build:
    name: Build and push image
    runs-on: ubuntu-20.04

    steps:
    - uses: actions/checkout@v2

    - name: Build Image
      id: build-image
      uses: redhat-actions/buildah-build@v2
      with:
        image: my-app
        tags: latest ${{ github.sha }}
        dockerfiles: |
          ./Dockerfile

    # Podman Login action (https://github.com/redhat-actions/podman-login) also be used to log in,
    # in which case 'username' and 'password' can be omitted.
    - name: Push To quay.io
      id: push-to-quay
      uses: redhat-actions/push-to-registry@v2
      with:
        image: ${{ steps.build-image.outputs.image }}
        tags: ${{ steps.build-image.outputs.tags }}
        registry: quay.io/quay-user
        username: quay-user
        password: ${{ secrets.REGISTRY_PASSWORD }}

    - name: Print image url
      run: echo "Image pushed to ${{ steps.push-to-quay.outputs.registry-paths }}"

Refer to GHCR push example for complete example of push to GitHub Container Registry (GHCR).

This action uses Podman to push, but can also push images built with Docker. However, Docker and Podman store their images in different locations, and Podman can only push images in its own storage.

If the image to push is present in the Docker image storage but not in the Podman image storage, it will be pulled into Podman's storage.

If the image to push is present in both the Docker and Podman image storage, the action will push the image which was more recently built, and log a warning.

If the action pulled an image from the Docker image storage into the Podman storage, it will be cleaned up from the Podman storage before the action exits.

We recommend using runs-on: ubuntu-20.04 since it has a newer version of Podman.

If you are on ubuntu-18.04 or any other older versions of ubuntu your workflow will use an older version of Podman and may encounter issues such as #26.

Note that quay.io repositories are private by default.

This means that if you push an image for the first time, you will have to authenticate before pulling it, or go to the repository's settings and change its visibility.

Simiarly, if you receive a 403 Forbidden from GHCR, you may have to update the Package Settings. Refer to this issue.