3

I am trying to run an Express API server with sudo permissions and have it automatically start on boot.

The API needs access to bcm2835 library, and I get the following when trying to run node server.js

bcm2835_init: Unable to open /dev/mem: Permission denied /home/pi/Documents/node_modules/rpio/lib/rpio.js:104 return bindfunc(optarg);

Error: Could not initialize bcm2835 library
at bindcall (/home/pi/...) etc.

However it boots up fine running sudo node server.js.

I have created a service file at /etc/systemd/system as follows:

[Unit]
Description=Node API
After=network.target

[Service]
ExecStart=/usr/bin/node /home/pi/Documents/server.js
Restart=always
SyslogIdentifier=controller
User=root
Group=root
Environment=

TimeoutStopSec=30

[Install]
WantedBy=multi-user.target

I found some guidance here and here, but they seem slightly off, since a sub-command needs sudo/root privileges.

How can I run this service with proper permissions so it boots up with the Pi?

I think the boot is failing silently in the background.

10
  • You probably need some environment variables for node to run and find the library.
    – RalfFriedl
    Nov 1 '18 at 14:18
  • Do you have an example? I'm not very familiar with environment variables, and I don't understand how a variable could be equivalent to running as sudo.
    – Matthew
    Nov 1 '18 at 14:21
  • It's not related tosudo. Type env and see what might be used by node.
    – RalfFriedl
    Nov 1 '18 at 15:00
  • Type env where?
    – Matthew
    Nov 1 '18 at 15:56
  • 1
    At a shell prompt.
    – RalfFriedl
    Nov 1 '18 at 15:57
1

/dev/mem must be run as root, so after a fresh install of Raspbian.

  1. Create the service

  2. Enable the service with systemctl enable nameOfService

2
  • 1
    It's enable instead of enbale.. :)
    – Pascal
    Jun 1 '20 at 17:57
  • Good catch. Thank you!!
    – Matthew
    Jun 2 '20 at 18:07

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