Zero Downtime Deployment with Docker Compose in an OCI VPS using GitHub Actions

# Create directory for Docker cli plugins
mkdir -p ~/.docker/cli-plugins

# Download docker-rollout script to Docker cli plugins directory
curl https://raw.githubusercontent.com/wowu/docker-rollout/master/docker-rollout -o ~/.docker/cli-plugins/docker-rollout

# Make the script executable
chmod +x ~/.docker/cli-plugins/docker-rollout

$ docker rollout -f docker-compose.yml <service-name>

name: CI

# 1
# Controls when the workflow will run
on:
  # Triggers the workflow on push events but only for the master branch
  push:
    branches: [main]

  # Allows you to run this workflow manually from the Actions tab
  workflow_dispatch:
    inputs:
      version:
        description: 'Image version'
        required: true
#2
env:
  REGISTRY: 'registry.digitalocean.com/YOUR_REGISTRY_NAME'
  IMAGE_NAME: 'YOUR_IMAGE_NAME'

#3
jobs:
  build_and_push:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout the repo
        uses: actions/checkout@v4

      - name: Build container image
        run: docker build -t $(echo $REGISTRY)/$(echo $IMAGE_NAME):$(echo $GITHUB_SHA | head -c7) .

      - name: Install doctl
        uses: digitalocean/action-doctl@v2
        with:
          token: ${{ secrets.DIGITALOCEAN_ACCESS_TOKEN }}

      - name: Log in to DigitalOcean Container Registry with short-lived credentials
        run: doctl registry login --expiry-seconds 600

      - name: Remove all old images
        run: if [ ! -z "$(doctl registry repository list | grep "$(echo $IMAGE_NAME)")" ]; then doctl registry repository delete-manifest $(echo $IMAGE_NAME) $(doctl registry repository list-tags $(echo $IMAGE_NAME) | grep -o "sha.*") --force; else echo "No repository"; fi

      - name: Push image to DigitalOcean Container Registry
        run: docker push $(echo $REGISTRY)/$(echo $IMAGE_NAME):$(echo $GITHUB_SHA | head -c7)

  deploy:
    runs-on: ubuntu-latest
    needs: build_and_push

    steps:
      - name: Deploy to Digital Ocean droplet via SSH action
        uses: appleboy/ssh-action@v1.0.3
        with:
          host: ${{ secrets.OCI_HOST }}
          username: ${{ secrets.OCI_USERNAME }}
          key: ${{ secrets.OCI_SSH_KEY }}
          envs: IMAGE_NAME,REGISTRY,{{ secrets.DIGITALOCEAN_ACCESS_TOKEN }},GITHUB_SHA
          script: |
            whoami
            cd ~/app
            pwd
            ls -la
            # Login to registry
            docker login -u ${{ secrets.DIGITALOCEAN_ACCESS_TOKEN }} -p ${{ secrets.DIGITALOCEAN_ACCESS_TOKEN }} registry.digitalocean.com
            # Update the APP image in docker-compose.yml
            sed -i '0,/image:/s|image: .*|image: '$(echo $REGISTRY)'/'$(echo $IMAGE_NAME)':'$(echo $GITHUB_SHA | head -c7)'|' docker-compose.yml
            # Pull the latest image
            docker compose pull
            # Here is the magic docker plugin
            docker rollout -f docker-compose.yml app
            echo "Deployed with success to production"