How to pass arguments to app using pm2?

Question

I am using pm2 to start my app but i am not able to pass argument to it. the command I am using is pm2 start app.js -- dev. Though this works with forever.

Answer 1

I have tested and it works in my windows machine. Below is the complete solution to pass arguments to nodejs app using pm2.

** There are also 2 types of argument

1. node-args - to use before npm start
2. args - to use in your node program

There are 2 ways to pass arguments with pm2.

Option 1: pass by argument with pm2 commands.

Option 2: by using config file e.g ecosystem.config.js

Option 1 (Pass arg by commands):

pm2 start app/myapp1.js --node-args="--max-http-header-size=80000" -- arg1 arg2

//Access the arg as below in your node program.
console.log(process.argv[2]); // arg1
console.log(process.argv[3]); // arg2

Option 2 (Using config file): If you are using ecosystem.config.js. you can define with the following configuration:

    {
      name: 'my-app',
      script: 'app\\myapp1.js',
      env: {
        NODE_ENV: 'DEV',
        PORT : 5051
      },
      node_args: '--max-http-header-size=80000',
      args : 'arg1 arg2',
      instances: 1,
      exec_mode: 'fork'
    }

To start as dev mode:

pm2 start --name myapp  app/myapp1.js -- .\ecosystem.config.js

To start as production mode, just add --env=production

pm2 start --name myapp  app/myapp1.js -- .\ecosystem.config.js --env=production 

//Access the arg as below in your node program.
console.log(process.argv[2]); // arg1
console.log(process.argv[3]); // arg2