Publish a Docker Image to Private Docker Hub Repo Using GitHub Actions

Overview #

In this article, I’ll cover how to publish a Docker image to a private Docker Hub repo when a new release is created using GitHub Actions.

GitHub Actions provide continuous integration capabilities in the form of workflows.

Workflows are defined in YAML files in the .github/workflows directory of a GitHub repository.

There are lots of built-in actions and third-party actions to choose from.

Create a Docker Hub Access Token #

Since we’ll be pushing our image to a private Docker Hub repository, we’ll need to generate an access token in Docker Hub so Github can authenticate successfully.

Click the New Access Token button which launches the modal shown below.

For Access Token Description, enter a descriptive name like “Github Actions Token".
For Access Permissions, select the Read & Write dropdown.
Click the Generate button
Copy the token to the clipboard

Create GitHub Secrets #

In the Github repository, go to Settings > Secrets and create the following secrets:

Name: DOCKER_HUB_USERNAME
Value: <username>

Name: DOCKER_HUB_ACCESS_TOKEN
Value: <access token>

GitHub Actions Workflow #

Now we are ready to create our workflow config file named .github/workflows/docker.yml.

The following workflow config builds an image based on a Dockerfile and publishes it to Docker Hub.

.github/workflows/docker.yml

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name: Publish Docker Image

on:
  push:
    tags:
      - '*'

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3
      - name: Login to DockerHub
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKER_HUB_USERNAME }}
          password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
      - name: Build and push
        id: docker_build
        uses: docker/build-push-action@v5
        with:
          push: true
          tags: user/app:${{ github.ref_name }}

Line 1: This is the name of the workflow and can be anything you want.
Lines 3-6: This section tells the workflow to fire whenever a tag is created.
Lines 12-13: This step is setting up our builder, this is the tool we are going to use to build our Docker image.
Lines 14-18: This step logs into Docker Hub with the secrets we created earlier.
Lines 19-24: This step builds the image with name user/app with the tag and pushes it to Docker Hub.

Create a release #

Following the steps here to create a release: Creating a Release

Check the action #

Let’s check the Actions tab to verify that the job steps completed successfully.

Check Docker Hub #

In the Docker Hub repository, you should see the new image that was pushed.