How do I run a node.js app as a background service

Question

Since this post has gotten a lot of attention over the years, I've listed the top solutions per platform at the bottom of this post.

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Original post:

I want my node.js server to run in the background, i.e.: when I close my terminal I want my server to keep running. I've googled this and came up with this tutorial, however it doesn't work as intended. So instead of using that daemon script, I thought I just used the output redirection (the 2>&1 >> file part), but this too does not exit - I get a blank line in my terminal, like it's waiting for output/errors.

I've also tried to put the process in the background, but as soon as I close my terminal the process is killed as well.

So how can I leave it running when I shut down my local computer?

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Top solutions:

• Systemd (Linux)
• Launchd (Mac)
• node-windows (Windows)
• PM2 (Node.js)

Answer 1

I use Supervisor for development. It just works. When ever you make changes to a .js file Supervisor automatically restarts your app with those changes loaded.

Here's a link to its Github page

Install :

sudo npm install supervisor -g

You can easily make it watch other extensions with -e. Another command I use often is -i to ignore certain folders.

You can use nohup and supervisor to make your node app run in the background even after you log out.

sudo nohup supervisor myapp.js &

Answer 2

If you are running nodejs in linux server, I think this is the best way.

Create a service script and copy to /etc/init/nodejs.conf

start service: sudo service nodejs start

stop service: sudo service nodejs stop

Sevice script

description "DManager node.js server - Last Update: 2012-08-06"
author      "Pedro Muniz - [e-mail]"

env USER="nodejs" #you have to create this user 
env APPNAME="nodejs" #you can change the service name
env WORKDIR="/home/<project-home-dir>" #set your project home folder here
env COMMAND="/usr/bin/node <server name>" #app.js ?

# used to be: start on startup
# until we found some mounts weren't ready yet while booting:
start on started mountall
stop on shutdown

# Automatically Respawn:
respawn
respawn limit 99 5

pre-start script
    sudo -u $USER echo "[`date -u +%Y-%m-%dT%T.%3NZ`] (sys) Starting" >> /var/log/$APPNAME.log
end script

script
    # Not sure why $HOME is needed, but we found that it is:
    export HOME="<project-home-dir>"  #set your project home folder here
    export NODE_PATH="<project node_path>"

    #log file, grant permission to nodejs user
    exec start-stop-daemon --start --make-pidfile --pidfile /var/run/$APPNAME.pid --chuid $USER --chdir $WORKDIR --exec $COMMAND >> /var/log/$APPNAME.log 2>&1
end script

post-start script
   # Optionally put a script here that will notifiy you node has (re)started
   # /root/bin/hoptoad.sh "node.js has started!"
end script

pre-stop script
    sudo -u $USER echo "[`date -u +%Y-%m-%dT%T.%3NZ`] (sys) Stopping" >> /var/log/$APPNAME.log
end script

Answer 3

2016 Update: The node-windows/mac/linux series uses a common API across all operating systems, so it is absolutely a relevant solution. However; node-linux generates systemv init files. As systemd continues to grow in popularity, it is realistically a better option on Linux. PR's welcome if anyone wants to add systemd support to node-linux :-)

Original Thread:

This is a pretty old thread now, but node-windows provides another way to create background services on Windows. It is loosely based on the nssm concept of using an exe wrapper around your node script. However; it uses winsw.exe instead and provides a configurable node wrapper for more granular control over how the process starts/stops on failures. These processes are available like any other service:

The module also bakes in some event logging:

Daemonizing your script is accomplished through code. For example:

var Service = require('node-windows').Service;

// Create a new service object
var svc = new Service({
  name:'Hello World',
  description: 'The nodejs.org example web server.',
  script: 'C:\\path\\to\\my\\node\\script.js'
});

// Listen for the "install" event, which indicates the
// process is available as a service.
svc.on('install',function(){
  svc.start();
});

// Listen for the "start" event and let us know when the
// process has actually started working.
svc.on('start',function(){
  console.log(svc.name+' started!\nVisit http://127.0.0.1:3000 to see it in action.');
});

// Install the script as a service.
svc.install();

The module supports things like capping restarts (so bad scripts don't hose your server) and growing time intervals between restarts.

Since node-windows services run like any other, it is possible to manage/monitor the service with whatever software you already use.

Finally, there are no make dependencies. In other words, a straightforward npm install -g node-windows will work. You don't need Visual Studio, .NET, or node-gyp magic to install this. Also, it's MIT and BSD licensed.

In full disclosure, I'm the author of this module. It was designed to relieve the exact pain the OP experienced, but with tighter integration into the functionality the Operating System already provides. I hope future viewers with this same question find it useful.

Answer 4

I am simply using the daemon npm module:

var daemon = require('daemon');

daemon.daemonize({
    stdout: './log.log'
  , stderr: './log.error.log'
  }
, './node.pid'
, function (err, pid) {
  if (err) {
    console.log('Error starting daemon: \n', err);
    return process.exit(-1);
  }
  console.log('Daemonized successfully with pid: ' + pid);

  // Your Application Code goes here
});

Lately I'm also using mon(1) from TJ Holowaychuk to start and manage simple node apps.

Answer 5

Copying my own answer from How do I run a Node.js application as its own process?

2015 answer: nearly every Linux distro comes with systemd, which means forever, monit, etc are no longer necessary - your OS already handles these tasks.

Make a myapp.service file (replacing 'myapp' with your app's name, obviously):

[Unit]
Description=My app

[Service]
ExecStart=/var/www/myapp/app.js
Restart=always
User=nobody
# Note Debian/Ubuntu uses 'nogroup', RHEL/Fedora uses 'nobody'
Group=nogroup
Environment=PATH=/usr/bin:/usr/local/bin
Environment=NODE_ENV=production
WorkingDirectory=/var/www/myapp

[Install]
WantedBy=multi-user.target

Note if you're new to Unix: /var/www/myapp/app.js should have #!/usr/bin/env node on the very first line.

Copy your service file into the /etc/systemd/system.

Start it with systemctl start myapp.

Enable it to run on boot with systemctl enable myapp.

See logs with journalctl -u myapp

This is taken from How we deploy node apps on Linux, 2018 edition, which also includes commands to generate an AWS/DigitalOcean/Azure CloudConfig to build Linux/node servers (including the .service file).

Answer 6

If you simply want to run the script uninterrupted until it completes you can use nohop as already mentioned in the answers here. However, none of the answers provide a full command that also logs stdin and stdout.

nohup node index.js >> app.log 2>&1 &

• The >> means append to app.log.
• 2>&1 makes sure that errors are also send to stdout and added to the app.log.
• The ending & makes sure your current terminal is disconnected from command so you can continue working.

If you want to run a node server (or something that should start back up when the server restarts) you should use systemd / systemctl.