Integrating GitHub Actions with Docker Builds

Introduction

Use GitHub Actions to automate Docker image builds, caching, and multi-architecture support directly in your repository CI.

Prerequisites

GitHub repository
Docker Hub or other registry credentials stored as GitHub Secrets

Step 1: Setup Secrets

Add to repository Settings > Secrets:

DOCKER_USERNAME
DOCKER_PASSWORD

Step 2: Create Workflow

In .github/workflows/docker.yml:

name: Docker CI

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

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repo
        uses: actions/checkout@v4

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v2

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Login to Docker registry
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      - name: Build and push Docker image
        uses: docker/build-push-action@v5
        with:
          context: .
          push: true
          tags: |
            yourusername/yourapp:latest
            yourusername/yourapp:${{ github.sha }}
          platforms: linux/amd64,linux/arm64
          cache-from: type=registry,ref=yourusername/yourapp:cache
          cache-to: type=registry,ref=yourusername/yourapp:cache,mode=max

      - name: Docker image digest
        run: echo "Image digest: ${{ steps.build.outputs.digest }}"

Step 3: Security Scanning

Extend with Trivy scan:

      - name: Scan Docker image for vulnerabilities
        uses: aquasec/trivy-action@v1
        with:
          image-ref: yourusername/yourapp:latest

Step 4: Build Artifacts

Optionally save image digests or metadata:

      - name: Upload build metadata
        uses: actions/upload-artifact@v3
        with:
          name: image-metadata
          path: build-metadata.json

Summary

GitHub Actions with docker/build-push-action and Buildx enables automated, multi-platform Docker builds with caching and security scanning in your CI pipeline.