# Manage Node.js Processes with PM2

# Prerequisites

A Node.js app (Next.js or otherwise) is servable
The Node.js app is not currently running
If using a virtual machine, port 3000 is forwarded

# Setup

Install PM2 globally using npm.

sudo npm install -g pm2

Create the file ~/apps/ecosystem.config.js.

module.exports = {
  apps: [{
    name: "[app name]",
    cwd: "/home/[username]/apps/[app name]",
    script: "node_modules/next/dist/bin/next",
    args: "start",
    instances: "max",
    exec_mode: "cluster",
    max_restarts: 5,
    log_date_format: "YYYY-MM-DDTHH:mmZ",
  }],
};

Make sure you replace [app name] and [username] with the appropriate values.

If you have more than one app, you can place more than one object in the apps array.

Start the process(es) using PM2.

pm2 start ~/apps/ecosystem.config.js

Open a web browser and navigate to http://[your server's IP address/hostname]:3000. You should see your Next.js app.

You can navigate to http://localhost:3000 as long as...

you're using a virtual machine,
are working from the host machine, and
you have port 3000 forwarded

Save the currently running configuration.

pm2 save

View the startup script command.

pm2 startup

That command will output a command that looks something like this:

sudo env PATH=$PATH:/usr/bin /usr/lib/node_modules/pm2/bin/pm2 startup systemd -u myuser --hp /home/myuser

Copy the command.

Paste it into your terminal and press Enter to run it.

PM2 will now automatically start the saved Node.js processes at system startup. Try restarting the machine to test it.

Right now, the process for updating the app is...

Push changes to the repository
Log into the server
Pull changes to the cloned (running) app
Install missing dependencies
Rebuild the app
Reload the pm2 processes

You can automate steps 2-6 with continuous integration.