一、安装

1、安装

npm install pm2 -g

2、更新

npm install pm2 -g && pm2 update

pm2 update 是为了刷新 PM2 的守护进程

二、使用 js 配置文件启动

1、生成配置文件

pm2 ecosystem

会自动生成 ecosystem.config.js 文件 (下文的 “五、配置文件实例” 会详细说到如何配置)

2、启动配置文件

pm2 start /path/ecosystem.config.js 

pm2 start /path/ecosystem.config.js -i max
// PM2 将自动检测可用 CPU 的数量并运行尽可能多的进程

三、管理 PM2 进程

1、常规

pm2 start

pm2 restart

pm2 reload

pm2 ls

pm2 stop

pm2 delete

restart vs reload

restart：pm2 同时杀死并重启所有进程。短时间内服务不可用

reload：pm2 逐个重启所有进程，但始终保持至少一个进程在运行

所以推荐使用 reload

2、操作多个进程

写法一：

pm2 restart / reload / stop / delete app1 app2 app3

写法二：

pm2 restart / reload / stop / delete all

3、保存 / 恢复进程 list

# save your list in hard disk memory
pm2 save

# resurrect your list previously saved
pm2 resurrect

4、监视进程

pm2 monit

5、使主机重启后可以恢复之前的进程

pm2 startup
//在 CLI 中复制并粘贴此命令的输出以设置启动挂钩

pm2 unstartup

四、日志

# all apps logs
pm2 logs

# only app logs
pm2 logs app

五、配置文件实例

module.exports = {
  /**
   * Application configuration section
   * http://pm2.keymetrics.io/docs/usage/application-declaration/
   */
  apps: [

    // First application
    {
      name: 'UB',
      script: './bin/www',
      instances: "max",
      env: {
        NODE_ENV: 'development'
      },
      env_testing: {
        NODE_ENV: 'testing'
      },
      env_production: {
        NODE_ENV: 'production'
      },
    //   log combines output and error, disabled by default
    //   "log": "./logs/combined.log", 
      "error_file": "./logs/pm2_UB_err.log",
      "out_file": "./logs/pm2_UB_out.log",
    //   In cluster mode, each cluster has his own log files. You can use the merge options to gather all logs into a single file
      "merge_logs": true, 
    //   "log_type"："json"
      "log_date_format": "YYYY-MM-DD HH:mm:ss Z"
    },

    // Second application
    {
      name: 'UB_schedule',
      script: './campaign_schedule.js',
      "error_file": "./logs/pm2_UB_schedule_err.log",
      "out_file": "./logs/pm2_UB_schedule_out.log",
      "merge_logs": true,
      "log_date_format": "YYYY-MM-DD HH:mm:ss Z"
    }
  ],

  /**
   * Deployment section
   * http://pm2.keymetrics.io/docs/usage/deployment/
   */
  deploy: { 

    testing: {
      user: 'universebackend',
      host: 'xxx.xx.93.179',
      ssh_options: "StrictHostKeyChecking=no",
      ref: 'origin/backend-api',
      repo: 'git@gitlab.example.com:production-team/universal_backend.git',
      path: '/home/universebackend/universalapi',
      
      'post-deploy': 'npm install --registry=https://registry.npm.taobao.org && pm2 startOrRestart ecosystem.config.js --env test',
    }

    production: {
    //   SSH key path, default to $HOME/.ssh
    //   key: "/path/to/some.pem",
      // SSH user
      user: 'universebackend',
      // SSH host
      host: ['xxx.xx.103.209', 'xxx.xx.98.216', 'xxx.xx.61.173'],
    //   SSH options with no command-line flag, see 'man ssh'
    //   can be either a single string or an array of strings
      ssh_options: "StrictHostKeyChecking=no",
    //   GIT remote/branch
      ref: 'origin/backend-api',
    //   GIT remote
      repo: 'git@gitlab.example.com:production-team/universal_backend.git',
    //   path in the server
      path: '/home/universebackend/givenchy',

    //   Pre-setup command or path to a script on your local machine
      pre-setup: "yum install git ; ls -la",
    //   Post-setup commands or path to a script on the host machine
    //   eg: placing configurations in the shared dir etc
      post-setup: "ls -la",

    //    pre-deploy action
      'pre-deploy-local': "echo 'This is a local executed command'",
    //   post-deploy action
      'post-deploy': 'npm install --registry=https://registry.npm.taobao.org && pm2 startOrRestart ecosystem.config.js --env production',
    }

  }

};

这里定义了 development | testing | production 三个环境变量

如何指定环境变量：

//启动
pm2 start ecosystem.config.js --env production

//更新
pm2 restart ecosystem.config.js --env production --update-env

nodejs中如何使用环境变量：

process.env.[环境变量]

if (process.env.NODE_ENV == "production") {

} else if (process.env.NODE_ENV == "testing") {
   
} else if (process.env.NODE_ENV == "development") {
   
} else {
    
}

3、deploy 部署

（1）跟要部署的远程服务器建立好 ssh 连接（使用 密钥认证 方式）

详见我的另一篇《 SSH 学习笔记 》

（2）先 setup

pm2 deploy ecosystem.config.js production setup

实质：执行了 git clone 的操作

（3）再 deploy

pm2 deploy ecosystem.config.js production

实质：执行了 git fetch 的操作

（4）其他操作

# Update remote version
pm2 deploy production update

# Revert to -1 deployment
pm2 deploy production revert 1

# execute a command on remote servers
pm2 deploy production exec "pm2 reload all"

（5）强制部署

如果你在本地修改了 ecosystem.config.js，却没有 push 到 github 上，这个时候 deploy 会报错：

--> Deploying to dev environment
--> on host 192.168.1.XX

  push your changes before deploying

Deploy failed

这时就可以使用到强制部署

pm2 deploy ecosystem.config.js production --force 

注：–force 只对 ecosystem.config.js 配置中的 “deploy” 部分有效，“apps” 部分依然是以 github 为准

参考资料：

1.【 pm官方文档 】https://pm2.io/doc/en/runtime/guide/installation/#install-pm2