Running as non-root

[reinzor]

Hi, thanks for the amazing library! I am able to use all functionality when I run as root. However, my application has to run as non-root user but it still needs to access the HID devices. I added the user to the input group and added a udev rule but it still does not work, see:

https://github.com/node-hid/node-hid/issues/140

Do you have any idea perhaps? Thanks!

[nightmode]

Super happy you like it. ^_^

I'm not too familiar with setting permissions on devices. Most likely because I use a Mac as my development machine and it seems happy as is.

Out of curiosity, what udev rule did you create? Is the rule inside a particularly named file? Are you using Ubuntu and if so, which version?

[reinzor]

This tutorial: https://puredata.info/docs/faq/how-can-i-set-permissions-so-hid-can-read-devices-in-gnu-linux/view

I am using Ubuntu/Linux 16.04; not sure whether this udev rule is necessary since adding the user to the input group already allows opening the device with cat.

[nightmode]

Ah, thanks for that link.

I added myself to the group "input" but it had no effect. Adding a udev rule after that had no effect either. Both procedures tried on Ubuntu 16.04.

I did find something interesting though!

Running node-hid/src/show-devices.js without sudo looks like this.

While running node-hid/src/show-devices.js with sudo looks like this.

The logitech-g29 library is looking for the string G29 Driving Force Racing Wheel in the product field which is one of the reasons it works with sudo.

I am currently playing with an updated findWheel() function inside the logitech-g29 library that also checks the vendorId and productId fields. It finds the wheel without sudo (yay) but then halts with an error (boo). Assuming permissions are the culprit again.

[reinzor]

Yes, I already noticed the mentioned issue. However, binding to the device without sudo throws the same error as you are getting :/.

Thanks for looking the issue!

-Rein

On Fri, May 27, 2016 at 4:14 PM, Daniel Gagan notifications@github.com wrote:

Ah, thanks for that link.

I added myself to the group "input" but it had no effect. Adding a udev rule after that had no effect either. Both procedures tried on Ubuntu 16.04.

I did find something interesting though!

Running node-hid/src/show-devices.js without sudo looks like this.

[image: show-devices] https://cloud.githubusercontent.com/assets/1933203/15609703/6a0753ea-23d6-11e6-858b-38bb13df875a.png

While running node-hid/src/show-devices.js with sudo looks like this.

[image: show-devices-with-sudo] https://cloud.githubusercontent.com/assets/1933203/15609711/74e7bd68-23d6-11e6-873b-1a399687d731.png

The logitech-g29 library is looking for the string G29 Driving Force Racing Wheel in the product field which is one of the reasons it works with sudo.

I am currently playing with an updated findWheel() function inside the logitech-g29 library that also checks the vendorId and productId fields. It finds the wheel without sudo (yay) but then halts with an error (boo). Assuming permissions are the culprit again.

[image: error] https://cloud.githubusercontent.com/assets/1933203/15610294/63ce8978-23d9-11e6-86c6-1d59ac2f4525.png

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/ForestMist/logitech-g29/issues/1#issuecomment-222157265, or mute the thread https://github.com/notifications/unsubscribe/AD-4l3kA2FWTq4al7QCTYuqV3TbA6M2Eks5qFvw-gaJpZM4InpeX .

[nightmode]

Updated code is live on GitHub and NPM.

More importantly, check out the updated install instructions at https://github.com/ForestMist/logitech-g29#install that detail how to create a special udev file. No group membership actions needed.

Works great on my test machine but I'll feel even better if you want to confirm that it also works on yours. :)

[reinzor]

Thanks a lot for your effort! I will test it and let you know on Monday!

Have a nice weekend.

-Rein

On 27 May 2016, at 19:46, Daniel Gagan notifications@github.com wrote:

Updated code is live on GitHub and NPM.

More importantly, check out the updated install instructions at https://github.com/ForestMist/logitech-g29#install that detail how to create a special udev file. No group membership actions needed.

Works great on my test machine but I'll feel even better if you want to confirm that it also works on yours. :)

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[reinzor]

I followed your tutorial and now it works as a train :). Thanks for your support!