Docker, Access to Raspberry Pi4 GPIO Pins

WebThings
#1

When running MozilaIOT in Docker on the Raspberry Pi 4, how can we expose the GPIO pins to the GPIO addon?

Running the following doesn’t seem to work:

docker run -v /sys/class/gpio:/sys/class/gpio

This is the error I get:

Failed to start add-on GPIO: No permissions to /sys/class/gpio/export

#2

Here are some instructions: https://stackoverflow.com/a/48234752

You’ll also need the proper permissions inside the container, which I’ve just merged a fix for. The images are rebuilding now.

#3

I’ve followed those instructions with

-v /sys/class/gpio:/sys/class/gpio

unfortunately it still doesn’t work, even running

–privileged

. Here;s my set up:

> docker run \

    --device /dev/gpiomem:/dev/gpiomem \
    -d \
    -e TZ="Europe/London" \
    -e Country="United Kingdom" \
    -e Language="English" \
    -v /path/to/shared/data:/home/node/.mozilla-iot \
    -v /sys/class/gpio:/sys/class/gpio \
    --network="host" \
    --log-opt max-size=1m \
    --log-opt max-file=10 \
    --name webthings-gateway \
    --restart=unless-stopped \
    mozillaiot/gateway:arm
#4

Are you using the latest Docker image? I rebuilt it a couple days ago with a fix for GPIO.

#5

No I wasn’t, I’ve just replaced the image. No error now, thank you for that. I still can’t seem to add GPIO pins, should they appear as things?

#6

You need to first configure the adapter via Settings -> Add-ons, then click Configure for GPIO. After setting up and applying your configuration, they’ll appear as things.

#7

I’ve configured and not had any error but there’s no sign of it as a thing.

#8

Did you click the + button on the Things screen and add it, or are you not even seeing it there?

#9

No unfortunately not

#10

Can you take a screenshot of the add-on configuration?

#11

Capture
Capture585×585 18.3 KB
I’d been trying a few different pin numbers.

#13

There seems to be no tag called arm.
Are you sure that’s the command you used?

I tried it on my pi 4, and the GPIO adapter fails due to /sys being read-only.
The privileged mode fixes it, though.

docker run \
    --privileged \
    -d \
    -e TZ="Europe/London" \
    -e Country="United Kingdom" \
    -e Language="English" \
    -v /path/to/shared/data:/home/node/.mozilla-iot \
    -v /sys/class/gpio:/sys/class/gpio \
    --network="host" \
    --log-opt max-size=1m \
    --log-opt max-file=10 \
    --name webthings-gateway \
    --restart=unless-stopped \
    mozillaiot/gateway
#14

That’s what I was using at the time but your right, I’ve since changed that to:

mozillaiot/gateway: latest

I wasn’t sure about using

–privileged

As the https://stackoverflow.com/a/48234752 thread seemed to advise against it

#15

Does yours work without privileged?

#16

Has anyone got this working without privileged? Thanks

#18

Hi t1m1, I new here. I have the same problem with the GPIO but also with the I2C add-on. I’m using a Pi4 with Ubuntu 20 where I succesfully installed the gateway. The errors are gpio-adapter: Failed to … /sys/class/gpio/export and generic-sensors-adapter: Failed to start … No permissions for I2C resource. After installing docker (it wasn’t) I tried your solution:
docker run \

–privileged
-d
-e TZ=“Europe/Madrid”
-e Country=“Spain”
-e Language=“English”
-v /path/to/shared/data:/home/.webthings
-v /sys/class/gpio:/sys/class/gpio
–network=“host”
log-opt max-size=1m
–log-opt max-file=10
–name webthings-gateway
–restart=unless-stopped
MYPATH/gateway
but getting the error: docker: invalid publish opts format (should be name=value but got ‘rivileged’). Problably is a very simple question but I’m getting started with the gateway.
Thanks!