Add CGroup Bind Mount Support

[ideonrandy]

Problem Statement

The label io.balena.features.sysfs mounts the host /sys to the container at /sys, but it doesn't mount /sys/fs/cgroup because it is a separate file system. As a result, we are unable to use systemd inside Docker containers when using the standard Balena deployment scheme (e.g. Balena push).

Possible Solution

In balena-supervisor/src/compose/utils.ts, add the following line to support this bind mount:

'io.balena.features.cgroupfs': () => service.config.volumes.push('/sys/fs/cgroup:/sys/fs/cgroup'),

[cywang117]

Hi @ideonrandy , Could you open a support ticket about this so we can better understand the need to access /sys/fs/cgroup? We're very conservative about adding new feature labels, as this means we have to support them in perpetuity. If you're not a paid user, you can create a forums post, which support agents also check and respond to. Thanks!