GitHub Actions: Build, Push Docker Image and Deploy

name: Build & Deploy

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

env:
  REGISTRY:   ghcr.io
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    outputs:
      image-tag: ${{ steps.meta.outputs.tags }}

    steps:
      - uses: actions/checkout@v4

      - name: Log in to GHCR
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract image metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=sha,prefix=sha-
            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/main' }}

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

      - name: Build and push
        uses: docker/build-push-action@v5
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags:   ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to:   type=gha,mode=max

  deploy:
    needs: build
    runs-on: ubuntu-latest
    if: github.ref == 'refs/heads/main'
    environment: production

    steps:
      - name: Deploy via SSH
        uses: appleboy/ssh-action@v1
        with:
          host:     ${{ secrets.DEPLOY_HOST }}
          username: ${{ secrets.DEPLOY_USER }}
          key:      ${{ secrets.DEPLOY_KEY }}
          script: |
            cd /srv/app
            echo ${{ secrets.GITHUB_TOKEN }} | docker login ghcr.io -u ${{ github.actor }} --password-stdin
            docker compose pull
            docker compose up -d --remove-orphans
            docker image prune -f