pm2 cluster_mode configuration file http://blog.fgribreau.com/2015/04/pm2-tips-uncommon-ssh-port-and.html

ecosystem.json

{
  "apps": [{
    "name": "My app",
    "script": "server.js",
    "instances": 2,
    "port": 8080,
    "exec_mode": "cluster_mode"
  }],
  "deploy": {
    "production": {
      "user": "node",
      "host": [{
        "host": "my-host-name -p 22115",
      }],
      "ref": "origin/master",
      "repo": "git@github.com:user/repo.git",
      "path": "/app",
      "post-deploy": "pm2 startOrRestart ecosystem.json --env production"
    }
  }
}