NodeJS服务通过PM2启动失败（停止或报错）求助

Hey there, let's work through why your PM2 commands are failing and get your service up and running smoothly. Here's a breakdown of the problems and solutions:

Why Your Current Commands Aren't Working #

1. pm2 start npm -- start stops unexpectedly
   Your start script uses nodemon, which is a development tool built for hot-reloading when files change. When PM2 runs this, nodemon's process management conflicts with PM2's own supervision—nodemon might exit or PM2 might not properly track it, leading to the service stopping. Nodemon isn't meant to be used alongside PM2 in production (or even managed PM2 environments).

2. pm2 start index.ts throws errors
   PM2 doesn't natively understand TypeScript files. By default, it tries to run .ts files as plain JavaScript, which causes syntax errors since it can't parse TypeScript syntax.

Step-by-Step Solutions #

Option 1: Directly Run TypeScript with PM2 (Recommended)

Skip the npm script and tell PM2 to use ts-node as the interpreter for your TypeScript entry file:

pm2 start ts-node -- index.ts

This tells PM2: "Use the ts-node executable to run index.ts"—which correctly handles TypeScript compilation on the fly.

Option 2: Use a Production-Focused NPM Script

If you prefer using npm scripts, split your development and production start commands to avoid nodemon in PM2:

1. Update your package.json scripts to add a production start command:

   "scripts": {
     "start": "nodemon --watch '**/*.ts' --exec ts-node index.ts", // Dev only
     "start:prod": "ts-node index.ts", // Production/PM2 use
     "bundle-colyseus-client": "browserify ./node_modules/colyseus.js/lib/index.js -s Colyseus -o static/colyseus.js",
     "build": "npm run bundle-colyseus-client",
     "heroku-postbuild": "npm run build"
   }
   

2. Start with PM2 using this new script:

   pm2 start npm -- run start:prod
   

Option 3: Use a PM2 Ecosystem Config File (For Advanced Management)

For better control over your app's configuration (like environment variables, file watching, or multiple instances), create an ecosystem.config.js file in your project root:

module.exports = {
  apps: [
    {
      name: "your-colyseus-app", // Name your service for easy PM2 management
      script: "index.ts",
      interpreter: "ts-node", // Tell PM2 to use ts-node
      watch: true, // Optional: Let PM2 handle file changes instead of nodemon
      env: {
        NODE_ENV: "development"
      },
      env_production: {
        NODE_ENV: "production"
      }
    }
  ]
};

Then start your app with:

pm2 start ecosystem.config.js
# For production mode:
pm2 start ecosystem.config.js --env production

Troubleshooting Tips #

• Always check PM2 logs for specific error details:

  pm2 logs
  

  This will show you exactly why the service stopped or threw an error (e.g., missing dependencies, TypeScript compilation issues).
• Check the status of your PM2 processes:

  pm2 status
  

  This tells you if the process is in an error, stopped, or online state.

内容的提问来源于stack exchange，提问作者david