如何通过 /etc/rc.local 运行我的 node.js 应用程序？

Question

I want to run a node application from my raspberry pi. The application is supposed to start on boot.

I have included the following lines in /etc/rc.local (before exit 0) :

    cd /home/pi/PPBot
    node bot.js > dev/null &

I first navigate to the correct folder and then run the bot from there. However the node application is not running when I reboot my raspberry pi. So it seems that rc.local is not executed or unable to execute the lines I provided.

I am looking for a solution so that the application will run at boot.

Answer 1

save this

[Unit]
Description=Node JS Script Service
After=network.target

[Service]
Type=simple
ExecStart=/usr/bin/node /path/to/hello_env.js
Restart=on-failure

[Install]
WantedBy=multi-user.target

to /etc/systemd/system/ as nodescript.service sudo systemctl daemon-reload sudo systemctl start nodescript if it worked, make it startup on boot sudo systemctl enable nodescript

Answer 2

The examples I 've seen (like this one ) used

cd /home/pi/PPBot
node bot.js < dev/null &

instead of

cd /home/pi/PPBot
node bot.js > dev/null &

Note the < instead of the > . As you can see here , the < redirects the Standard In (stdin), while the > redirects the Standard Output (stdout). And as described here ,

< /dev/null is used to instantly send EOF to the program, so that it doesn't wait for input ( /dev/null , the null device, is a special file that discards all data written to it, but reports that the write operation succeeded, and provides no data to any process that reads from it, yielding EOF immediately). & is a special type of command separator used to background the preceding process.

Since you havent used < dev/null , maybe your program is stuck and waits for some input. The & at the end makes your program run in the background. Try to not include it and see if your Rasberry Pi is still booting. If not, you know that your programs runs continously and blocks further booting; when you used the & sign, your program just failed in a separate process. In this case changing the > to < should help because your programs doesn't wait for input.

If the above doesn't work, update your question with the specific error message. You can view the boot log by using the command dmesg (display message).

Answer 3

In this case when you cd /home/pi/PPBot you are no longer in the root directory so when you run node bot.js > dev/null & it is looking for the dev folder at /home/pi/PPBot/dev

You will need to add a leading / to ensure it is accessing /dev

change

node bot.js > dev/null &

to

node bot.js > /dev/null &