Blue Green Deployment with Traefik and automatic git sync

10m.sh

#!/usr/bin/env bash

output=$(git pull)

if [[ $output == *"Already up to date."* ]]; then
  echo "No changes detected."
else
  echo "Changes detected."
  color=$(grep file dynamic/http.routers.docker-localhost.yml | cut -d' ' -f8 | cut -d'@' -f 1);
  new_color=$([ "$color" = "green" ] && echo "blue" || echo "green")
  echo "Current deploy is $color"
  sudo docker-compose -f docker-compose.yml build $new_color
  sudo docker-compose -f docker-compose.yml up -d $new_color
  sed -e s/$color/$new_color/ dynamic/http.routers.docker-localhost.yml > /tmp/temp.yml
  mv /tmp/temp.yml dynamic/http.routers.docker-localhost.yml
  sleep 20
  sudo docker-compose -f docker-compose.yml build $color
  sudo docker-compose -f docker-compose.yml up -d $color
fi

README.md

Instructions

Install docker-compose and gpg.

sudo apt install docker-compose gpg

Run ./install.sh.

It will install a service into /etc/systemd/system/app.service which will be run every 10m.

The service will git clone and zero downtime deploy changes

app.service

[Unit]
Description=app service

[Service]
Type=oneshot
WorkingDirectory=/root/app/deploy/
ExecStart=/bin/bash /root/appa/deploy/10m.sh

app.timer

[Unit]
Description=app timer

[Timer]
OnUnitActiveSec=10m
OnBootSec=10s

[Install]
WantedBy=timers.target

docker-compose.yml

version: '3.8'

services:
  traefik:
    image: traefik:v2.4
    ports:
      - 80:80
      - 443:443
      - 8080:8080
    volumes:
      - ./traefik.yml:/etc/traefik/traefik.yml
      - ./dynamic:/etc/traefik/dynamic:ro
  blue:
    build:
      context: ../..
      dockerfile: Dockerfile
    deploy:
      replicas: 2
    env_file:
      - ./app.env
    volumes:
      - ./db.sqlite:/app/prisma/db.sqlite
      - ./uploads:/app/uploads

  green:
    build:
      context: ../..
      dockerfile: Dockerfile
    deploy:
      replicas: 2
    env_file:
      - ./app.env
    volumes:
      - ./db.sqlite:/app/prisma/db.sqlite
      - ./uploads:/app/uploads

http.routers.blue-docker-localhost.yml:

http:
  routers:
    blue-docker-localhost:
      rule: Host(`blue.docker.localhost`)
      service: blue@file

http.routers.green-docker-localhost.yml:

http:
  routers:
    green-docker-localhost:
      rule: Host(`green.docker.localhost`)
      service: green@file

http.routers.host.yml.example

http:
  routers:
    docker-localhost:
      rule: Host(`docker.localhost`)
      service: green@file

http.services.blue.yml

http:
  services:
    blue:
      loadBalancer:
        servers:
          - url: 'http://blue:3000/'

http.services.green.yml

http:
  services:
    green:
      loadBalancer:
        servers:
          - url: 'http://green:3000/'

install.sh

#!/usr/bin/env bash
gpg -d app.env.gpg > app.env
cp http.routers.host.yml.example dynamic/http.routers.host.yml
sudo docker-compose -f docker-compose.yml up -d
echo "Installing service into /etc/systemd/system/app.service"
sudo cp app.service /etc/systemd/system/app.service
echo "Running every 10m as per /etc/systemd/system/app.service"
sudo cp app.timer /etc/systemd/system/app.timer
sudo systemctl daemon-reload
sudo systemctl enable --now papp.timer

traefik.yml

entryPoints:
  http:
    address: ":80"
  https:
    address: ":443"

providers:
  file:
    directory: /etc/traefik/dynamic
    watch: true

api:
  dashboard: true
  insecure: true