Build a Docker image (single-arch)

This workflows builds a Docker image for a single architecture, and deploys it to a server.

.github/workflows/build.yml

name: 'Build and publish'

on:
  workflow_dispatch:
    # Allows to manually run the workflow from GitHub's UI
  schedule:
    # Rebuilds the image automatically every Saturday,
    # to ensure it stays up-to-date and secure
    - cron: '0 4 * * 6'
  push:
    branches:
      - 'main'

jobs:
  build:
    name: 'Build Docker image and push to GHCR'
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - name: Calculate short form of current git commit
        id: vars
        run: echo "sha_short=$(git rev-parse --short HEAD)" >> "$GITHUB_OUTPUT"

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2

      - name: Login to GitHub Container Registry
        uses: docker/login-action@v2
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build and push Docker image
        uses: docker/build-push-action@v4
        with:
          push: true
          context: .
          tags: ghcr.io/${{ github.repository }}:latest,ghcr.io/${{ github.repository }}:git-${{ steps.vars.outputs.sha_short }}
          cache-from: type=registry,ref=ghcr.io/${{ github.repository }}-buildcache
          cache-to: type=registry,ref=ghcr.io/${{ github.repository }}-buildcache,mode=max

      - name: Replace variables in stack file
        env:
          IMAGE_TAG: git-${{ steps.vars.outputs.sha_short }}
        run: >
          sed -e "s/\${IMAGE_TAG}/$IMAGE_TAG/" \
              -i .github/workflows/deploy/stack.yml
              
          cat .github/workflows/deploy/stack.yml

      - name: Trigger deployment
        env:
          API_KEY: ${{ secrets.StackSparkApiKey }}
          STACKSPARK_HOST: ${{ secrets.StackSparkHost }}
          STACK_NAME: notes
        run: >
          curl --fail -H "X-API-Key: $API_KEY" --data-binary "@.github/workflows/deploy/stack.yml" https://$STACKSPARK_HOST/deploy?stackName=$STACK_NAME