I have a fresh install of Alpine Linux on my laptop, and I'm trying to read the battery information from
/sys/class/power_supply/BAT0/uevent as a regular user (non root). The permissions on the uevent and similar files are readable (set to 744), but the directory structure preceding it (specifically
/sys/class/power_supply) have permissions set to 700. This ultimately prevents me from reading the uevent file.
I have another setup with Alpine Linux installed in which these directories are set to permissions 751, allowing me to add my user to the root group in order to access the information.
/sys consists only of virtual files that allow access to the active kernel, how then is it possible that two systems on identical kernels boot with different permissions set for these directories?