push-to-registry/README.md

push-to-registry

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.

To log in to a container image registry, podman-login action can be used.

Action Inputs

Refer to the podman push documentation for more information.

Input Name	Description	Default
image	Name of the image you want to push.	Required
tags	The tag or tags of the image to push. For multiple tags, seperate by a space. For example, latest ${{ github.sha }}	latest
registry	URL of the registry to push the image to. Eg. quay.io/<username>	Required
username	Username with which to authenticate to the registry. Required unless already logged in to the registry	None
password	Password, encrypted password, or access token with which to authenticate to the registry. Required unless already logged in to the registry	None
tls-verify	Verify TLS certificates when contacting the registry. Set to false to skip certificate verification.	true
digestfile	After copying the image, write the digest of the resulting image to the file. The contents of this file are the digest output.	Auto determined from image and tag
extra-args	Extra args to be passed to podman push. Separate arguments by newline. Do not use quotes.	None

Action Outputs

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.

Examples

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
    env:
      IMAGE_NAME: my-app
      IMAGE_TAGS: latest v1
      REGISTRY_USER: quayuser
      REGISTRY_PASSWORD: ${{ secrets.REGISTRY_PASSWORD }}

    steps:
    - uses: actions/checkout@v2

    - name: Build Image
      id: build-image
      uses: redhat-actions/buildah-build@v2
      with:
        image: ${{ env.IMAGE_NAME }}
        tags: ${{ env.IMAGE_TAGS }}
        base-image: some_image
        dockerfiles: |
          ./Dockerfile

    # Podman Login action (https://github.com/redhat-actions/podman-login) can be used
    # in the previous step to log in to a container registry. In that case input "username"
    # "password" can be omitted in this push action.
    - 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: ${{ secrets.QUAY_REPO }}
        username: ${{ env.REGISTRY_USER }}
        password: ${{ env.REGISTRY_PASSWORD }}

    - name: Use the image
      run: echo "New image has been pushed to ${{ steps.push-to-quay.outputs.registry-paths }}"

Note about images built with Docker

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.

Note about GitHub runners and Podman

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

If you are on ubuntu-18.04 (which is currently aliased to ubuntu-latest) your workflow will use an older version of Podman and may encounter issues such as #26.

Troubleshooting

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.