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Publishing to Docker Hub

At Space 48, we publish Docker images to our organisation account on Docker Hub.

Docker Hub Organisation​

Our Docker images are published to the Space 48 organisation on Docker Hub:

Authentication​

For CI/CD pipelines, we use workspace variables for authentication:

  • DOCKERHUB_USERNAME - Bot account username for Docker Hub
  • DOCKERHUB_PASSWORD - Bot account password/token for Docker Hub
  • DOCKERHUB_NAMESPACE - The organisation namespace (space48)

These variables are available in both Bitbucket and GitHub CI environments as workspace variables.

Publishing Process​

CI/CD Publishing​

The preferred method for publishing Docker images is to use a CI/CD pipeline.

Bitbucket Pipelines​

Example Bitbucket pipeline file bitbucket-pipelines.yml:

image:
  name: atlassian/default-image:2

pipelines:
  branches:
    main:
      - step:
          name: Build and Push
          script:
            # Build and push image
            - VERSION="1.$BITBUCKET_BUILD_NUMBER"
            - echo ${DOCKERHUB_PASSWORD} | docker login --username "$DOCKERHUB_USERNAME" --password-stdin
            - IMAGE="$DOCKERHUB_NAMESPACE/$BITBUCKET_REPO_SLUG"
            - docker build -t ${IMAGE}:${VERSION} .
            - docker tag ${IMAGE}:${VERSION} ${IMAGE}:latest
            - docker push ${IMAGE}
            # Push tags
            - git tag -a "${VERSION}" -m "Tagging for release ${VERSION}"
            - git push origin ${VERSION}
          services:
            - docker

GitHub Actions​

Example GitHub workflow file .github/workflows/docker-publish.yml:

name: Docker

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3

      - name: Login to Docker Hub
        uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_PASSWORD }}

      - name: Build and push
        uses: docker/build-push-action@v4
        with:
          push: true
          tags: ${{ secrets.DOCKERHUB_NAMESPACE }}/your-image-name:latest

Best Practices​

  1. Use Semantic Versioning: Tag your images with semantic versions (e.g., 1.0.0, 1.1.0) in addition to latest.

  2. Multi-stage Builds: Use multi-stage builds to keep your images small and secure.

  3. Documentation: Include a README in your Docker image repository with usage instructions.

  4. Security Scanning: Enable vulnerability scanning for your Docker images.

  5. Base Images: Use official, minimal base images when possible (e.g., alpine variants).

  6. Image Cleanup: Implement a policy for cleaning up old or unused images.