build-docker.yml

# -----------------------------------------------------------------------------
# GitHub Actions Workflow: Build & Push KubernetesLabs Docker Image to GHCR
#
# Builds a standalone Docker image containing all tools (Kind, kubectl, Helm,
# k9s, kubewall) and lab content, then pushes to GHCR as multi-arch.
#
# Published to ghcr.io/<owner>/kubernetes-labs with `latest` and `sha-<short>` tags.
# -----------------------------------------------------------------------------

name: Build Docker Image

# Event triggers for the workflow
on:
  push:
    branches:
      - main
      - master
    paths:
      - "docker/**"
      - "Labs/**"
  workflow_dispatch:

# Workflow permissions
permissions:
  contents: read
  packages: write

# Concurrency settings
concurrency:
  cancel-in-progress: true
  group: "docker-build"

# The build job
jobs:
  build-and-push:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

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

      - name: Login to GitHub Container Registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata (tags, labels)
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ghcr.io/${{ github.repository_owner }}/kubernetes-labs
          tags: |
            type=raw,value=latest
            type=sha,prefix=sha-,format=short

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          context: .
          file: docker/Dockerfile
          platforms: linux/amd64,linux/arm64
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max