Front-Commerce and PM2

Front-Commerce is a node.js application. You may want to run it in production with the PM2 Process Manager. This page explains how you could achieve this, and benefit from PM2 features such as; zero-downtime deployment, cluster mode, auto-reload, logs aggregation…

note

PM2 is not the only way to deploy Front-Commerce in production, however, we often get asked about how PM2 should be configured for Front-Commerce. This page is here to get you started but we recommend that you discuss it with your system administrator.

ecosystem.config.js

We recommend to use an ecosystem.config.js file so you could track changes to your deployment configuration, however these settings can also be passed to PM2 CLI.

Below is an annotated example of configuration:

module.exports = {
  apps: [
    {
      name: `frontcommerce-app`,
      cwd: `/path/to/your/frontcommerce/app`,

      // This is how you could start Front-Commerce in a cluster-mode compatible way
      script: `./node_modules/front-commerce/src/server/index.js`,

      // Running the script as shown above will prevent Front-Commerce
      // to find the `.env` file usually located at your project's root.
      // Using this node argument is the recommended way to load those variables
      node_args: "-r dotenv/config",

      // collocate PM2 logs with default Front-Commerce logs
      error_file: "./logs/pm2-err.log",
      out_file: "./logs/pm2-out.log",
      log_file: "./logs/pm2-combined.log",

      // It is safe to let PM2 restart your processes in case of
      // an unexpected failure, or if they consume too much memory.
      // Memory leaks on long-running processes such as node servers
      // are common, and it is safe to have a watchdog for them
      autorestart: true,
      max_memory_restart: "2G", // adapt this value to your environment
      restart_delay: 1000, // prevents flooding the server with restarts
      kill_timeout: 15000, // allows Front-Commerce to end existing connections properly
      wait_ready: true, // allows to wait for server start to prevent 502 errors

      // PM2's cluster mode allows your application to leverage all
      // the CPUs available on your server. It is a good way to make
      // your app faster.
      instances: "max",
      exec_mode: "cluster",

      env: {
        // You may also prefer to use this configuration file
        // to define environment variables
      },
    },
  ],
};

note

This page only focuses on Front-Commerce related configurations. You should look into additional PM2 configuration keys and ensure they are adapted to your deployment environment for an optimal configuration.

Start your application

If an ecosystem.config.js file is versioned at the root of your project, you could then start or replace your Front-Commerce app in production with a new version using the command below:

pm2 reload ecosystem.config.js

It will allow you to deploy the new version of your application with zero downtime!

For other questions about using PM2, we recommend that you read their official documentation.