There is a chance that you might need to involve using both of upstart and systemd to initialize your process. Mostly the first major benefit to get from starting process via upstart or systemd is to get automatic restart when either of your system or process dies. Yes, you have customers to serve, minimizing down-time as much as possible is better.

So let's see how we could configure these things up with both upstart, and systemd.

Scenario

Let's assume that you're root, and you want to execute your NodeJS-based program in the background which its main file locates at ~/my-process/index.js .

The program itself also accepts 2 environment variables namely ENV_VAR1 and ENV_VAR2.

You also want to log its output (included its error output) to /var/log/my-process.log. As well, you want to log date-time of process starting and ending.

The important thing is that you want to have such program automatically restarts when it dies, or system reboots.

upstart

---

Configuration below is based on Linux Ubuntu 14.04. But it should be similar to other modern systems.

1. Create my-process.conf file at /etc/init/ with the following content

description "My Process"
author "haxpor"

start on runlevel [2345]

respawn

script
  exec ENV_VAR1='My 1st parameter' ENV_VAR2='My 2nd parameter' node ~/my-process/index.js >> /var/log/my-process.log
end script

pre-start script
  echo "[`date`] my-process is starting" >> /var/log/my-process.log
end script

pre-stop script
  echo "[`date`] my-process stopping" >> /var/log/my-process.log
end script

Notice that in exec ... inside script and end script. This is one line. But you can substitute the following for multiple lines.

...
script
  chdir ~/my-process
  export ENV_VAR1='My 1st parameter'
  export ENV_VAR2='My 2nd parameter'
  exec node ~/my-process/index.js >> /var/log/my-process.log 2>&1
end script
...

2. Check configuration file syntax by executing

 init-checkconf /etc/init/my-process.conf

Then you should see that syntax is OK as follows.

File /etc/init/my-process.conf: syntax ok

3. Reload configurations to let upstart knows our new configuration file.
   Execute the following command.

initctl reload-configuration

If you didn't see any error, then it's alright.

4. Start my-process by executing

 start my-process

You will see the following output

 my-process start/running, process 20341

5. Other commands
   As well, you can execute start/stop/status/restart command for such process in the same way you did in 4 i.e. stop my-process.

6. At this point when you try to reboot the system, you can see that such process will be automatically started. Or you can try to kill such process then it will be automatically restarted as well.

7. (Bonus) See status for all services by executing initctl list.

systemd

---

Configuration below is based on CentOS 7. But it should be similar to other modern systems.

1. Create my-process.service file at /etc/systemd/system with the following content.

[Unit]
Description=my-process
After=syslog.target network.target remote-fs.target nss-lookup.target

[Service]
Type=simple
Environment=ENV_VAR1='My 1st parameter' ENV_VAR2='My 2nd parameter'
ExecStart=/usr/bin/node ~/my-process/index.js
Restart=always

[Install]
WantedBy=multi-user.target

Notice that we didn't specify ... >> /var/log/my-process.log 2>&1 as I found it has a problem with systemd. I think it's better to avoid it. But we're going to use journalctl to see log output instead, keep reading.

2. Check configuration by executing

systemd-analyze verify /etc/systemd/system/my-process.service

If there is no error, you should not see any error message. Anyway, the following output can be ignored, in case you see.

Configuration file /usr/lib/systemd/system/YDService.service is marked executable. Please remove executable permission bits. Proceeding anyway.
Binding to IPv6 address not available since kernel does not support IPv6.
[/usr/lib/systemd/system/rpcbind.socket:6] Failed to parse address value, ignoring: [::]:111

Above is OK.
Below is not OK.

Configuration file /usr/lib/systemd/system/YDService.service is marked executable. Please remove executable permission bits. Proceeding anyway.
Binding to IPv6 address not available since kernel does not support IPv6.
[/usr/lib/systemd/system/rpcbind.socket:6] Failed to parse address value, ignoring: [::]:111
[/etc/systemd/system/heatap-server-debug.service:15] Missing '='.
Error: org.freedesktop.DBus.Error.InconsistentMessage: Unit is not loaded properly: Bad message.
Failed to create heatap-server-debug.service/start: Bad message

3. Restart daemon to let systemd knows your new configuration file. Execute the following

systemctl daemon-reload

You won't see any output if it's ok.

4. Enable my-process service by executing

systemctl enable my-process

Notice that you can omit .service

5. Start my-process service by executing

systemctl start my-process

6. Other commands
   As well, you can execute start/stop/status/restart command for such process in the same way you did in 4 i.e. systemctl stop my-process.

7. At this point when you try to reboot the system, you can see that such process will be automatically started. Or you can try to kill such process then it will be automatically restarted as well.

8. You can see log by executing

journalctl -u my-process