process.json

{
    "apps": [
        {
            "name": "the-city",
            "script": "./server.js",
            "watch": true,
            "merge_logs": true,
            "max_restarts": 5,
            "instances": 1,
            "max_memory_restart": "200M",
            "env": {
                "NODE_ENV": "development"
            },
            "env_production" : {
                "NODE_ENV": "production"
            }
        }
    ]
}