bootstrap_swarm.sh

#!/bin/bash

# https://codefresh.io/blog/deploy-docker-compose-v3-swarm-mode-cluster/

# vars
[ -z "$NUM_WORKERS" ] && NUM_WORKERS=3

# init swarm (need for service command); if not created
docker node ls 2> /dev/null | grep "Leader"
if [ $? -ne 0 ]; then
  if [ "$(hostname -i)" = "127.0.0.1" ]; then
    # vagrant environment
    docker swarm init --advertise-addr=192.168.56.10
  else
    docker swarm init
  fi
fi

# get join token
SWARM_TOKEN=$(docker swarm join-token -q worker)

# get Swarm master IP (Docker for Mac xhyve VM IP)
SWARM_MASTER=$(docker info --format "{{.Swarm.NodeAddr}}")
echo "Swarm master IP: ${SWARM_MASTER}"
sleep 10

# start Docker registry mirror
docker run -d --restart=always -p 4000:5000 --name v2_mirror \
  -v $PWD/rdata:/var/lib/registry \
  -e REGISTRY_PROXY_REMOTEURL=https://registry-1.docker.io \
  registry:2.5

# run NUM_WORKERS workers with SWARM_TOKEN
for i in $(seq "${NUM_WORKERS}"); do
  # remove node from cluster if exists
  docker node rm --force $(docker node ls --filter "name=worker-${i}" -q) > /dev/null 2>&1
  # remove worker contianer with same name if exists
  docker rm --force $(docker ps -q --filter "name=worker-${i}") > /dev/null 2>&1
  # run new worker container
  docker run -d --privileged --name worker-${i} --hostname=worker-${i} \
    -p ${i}2375:2375 \
    -p ${i}5000:5000 \
    -p ${i}5001:5001 \
    -p ${i}5601:5601 \
    -p ${i}3306:3306 \
    -p ${i}3307:3307 \
    -p ${i}3308:3308 \
    -p ${i}7946:7946 \
    -p ${i}7946:7946/udp \
    -p ${i}4789:4789/udp \
    docker:stable-dind --registry-mirror http://${SWARM_MASTER}:4000
  sleep 1
  # add worker container to the cluster
  docker --host=localhost:${i}2375 swarm join --token ${SWARM_TOKEN} ${SWARM_MASTER}:2377
done

# show swarm cluster
printf "\nLocal Swarm Cluster\n===================\n"

docker node ls

# echo swarm visualizer
printf "\nLocal Swarm Visualizer\n===================\n"
docker run --rm -it -d --name swarm_visualizer \
  -p 8081:8080 -e HOST=localhost \
  -v /var/run/docker.sock:/var/run/docker.sock \
  dockersamples/visualizer

docker-compose.swarm.yml

version: '3'
services:

  master:
    image: jamiejackson/mariadb-replication:10.2
    ports:
      - "3307:3306"
    restart: unless-stopped
    environment:
      - MYSQL_ALLOW_EMPTY_PASSWORD=1
      # - MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PASSWORD}

  slave:
    image: jamiejackson/mariadb-replication:10.2
    depends_on:
      - "master"
    ports: 
     - "3308:3306"
    restart: unless-stopped
    environment:
      - MYSQL_ALLOW_EMPTY_PASSWORD=1
      - MASTER_HOST=master
      - MASTER_PORT=3306
      # - MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PASSWORD}

start

docker stack deploy --compose-file=docker-compose.swarm.yml db