pm2的cluster模式下使用log4js

{
  /**
   * pm2 (boolean) (optional)
   * - set this to true if you’re running your app using pm2,
   * otherwise logs will not work (you’ll also need to install pm2-intercom as pm2 module: pm2 install pm2-intercom)
   */
  pm2: true,
  /**
   * pm2InstanceVar (string) (optional, defaults to ‘NODE_APP_INSTANCE’)
   * - set this if you’re using pm2 and have changed the default name of the NODE_APP_INSTANCE variable.
   */
  pm2InstanceVar: "isMaster"
  /**
   * disableClustering (boolean) (optional)
   * - set this to true if you liked the way log4js used to just ignore clustered environments,
   * or you’re having trouble with PM2 logging. Each worker process will do its own logging. Be careful with this if you’re logging to files, weirdness can occur.
   */
  // disableClustering: true,
    ...
}

{
  "apps": [
    {
      "name": "name",
      "script": "bin/run",
      "exec_mode": "cluster",
      "ignoreWatch": ["node_modules"],
      "instances": "4", #配置`max`,则自动匹配当前机器的cpu数
      "watch": false,
      "error_file": "log/pm2/error.log", #如果不输出则配置`/dev/null`
      "out_file": "log/pm2/out.log",  #如果不输出则配置`/dev/null`
      "pid_file": "log/pm2/pid.log",  #如果不输出则配置`/dev/null`
      "merge_logs": true, #让所有进程日志都写进同一个日志,启动时添加参数--merge-logs <具体日志文件>
      "instance_var": "isMaster" #对应pm2InstanceVar
    }
  ]
}