Missing linux groups cause HM-MOD-RPI-PCB connection to fail

[lhurt]

The current docker images are missing the groups dialout, spi and gpio causing a failure when operating the HM-MOD-RPI-PCB hardware. The error reads
HomeMatic BidCoS: HM-MOD-RPI-PCB "My-HM-MOD-RPI-PCB": Error in file PhysicalInterfaces/Hm-Mod-Rpi-Pcb.cpp line 810 in function void BidCoS::Hm_Mod_Rpi_Pcb::doInit(): Failed to open GPIO value file "/sys/class/gpio/gpio18/value": Permission denied

This is cause by the absence of the groups mentioned and thus the homegear user can't be member of them. Adding the additional build step

FROM homegear/homegear:stable
ARG HOST_GROUP_GPIO_UID="gpio gruppen uid des hosts setzen"
ARG HOST_GROUP_I2C_UID="i2c gruppen uid des hosts setzen"
ARG HOST_GROUP_SPI_UID="spi gruppen uid des hosts setzen"

RUN groupadd -g $HOST_GROUP_GPIO_UID gpio && usermod -a -G gpio homegear && \
    groupadd -g $HOST_GROUP_I2C_UID i2c && usermod -a -G i2c homegear && \
    groupadd -g $HOST_GROUP_SPI_UID spi && usermod -a -G spi homegear

fixes this issue. As I suppose that this issue should be fixed in the install process of the respecting package rather than in the docker file I can't file a pull request because I don't know much about the debian apt procedures.

May I'd like to add the finding that the docker image doesn't work in debian bookworm at all because it seems to me that the access via /sys/class/gpio/gpio18/ was removed. I can file a separate ticket for this if you request me to do so.