Hey
I have not been able to reproduce this. This is the output from a privileged container
root@12fb630:/usr/src/app# i2cdetect -l
i2c-1 i2c bcm2835 (i2c@7e804000) I2C adapter
root@12fb630:/usr/src/app# i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- 4c -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
Could this be because you are running modprobe i2c-dev during the docker image build phase?
I was able to use i2c-detect without modprobe i2c-dev. If you want to run it at runtime, you should also install kmod since balenalib/rpi-raspbian base image doesn’t ship the modprobe command.
You can also simplify your dockerfile as follows:
FROM balenalib/rpi-raspbian
RUN install_packages i2c-tools
...
You can read more about the install_packages utility here https://www.balena.io/docs/reference/base-images/base-images/#installing-packages