Introduction

NodeJS is a great tool for web development, but it has it’s hang-ups. When setting up an Express Server with NodeJS, many restarts are required and expected during the development stage. Not only that, but it would be great to keep a NodeJS project running indefinitely once you close your terminal session. This tutorial aims to address both of those issues. This tutorial will start by addressing the desire to keep a nodeJS process running and will then address reloading the process when changes are made. I will do this by addressing different tools used to accomplish these tasks and will end with my preferred option. Let’s begin.

NOTE: THIS IS COPIED FROM A WORDPRESS BLOG AND THEREFORE SOME STYLES AND TEXT DID NOT TRANSFER OVER PROPERLY

Video (for all of you non-readers out there)

The Options:

Tmux/Screen (Okay Option)

Tmux and Screen are terminal multiplexers that allow you to create “sessions” that can persist after you close your terminal. They create their own sockets that a terminal instance runs in. A user can then access this through their tool’s commands. Once inside one of these sessions, running a command with node and then leaving the session will not end the node process because the terminal session is still open. I won’t go into detail here, but if you watch the video, I will show how to do this with tmux.

Nodemon (Better Option)

One of the issues with the above method is that you still need to stop and restart the node process every time you make a change to the server. One work-around for this is to install nodemon, a nodejs wrapper that watches the files in the directory it is run it and restarts. Nodemon is a node module and can be installed with npm. Combining nodemon with tmux or screen will allow you to run a node server that restarts whenever a change occurs. There is an easier way.

PM2 (Best Option)

PM2 is a Process Manager for NodeJS. Like nodemon, it is also installed globally through npm. Unlike nodemon, pm2 actually creates a system process independent of any terminal instance to run your node process in. The video shows how to set it up after installing so I won’t discuss it here. They have some great documentation at their site.

Conclusion

There are different ways to accomplish the task of running node forever, but my favorite, since I first started using it, is PM2. It allows users to monitor multiple node processes, watch the files for changes, and even run in a clustered mode for load-balancing purposes.