Mount hosts /proc & /sys into add on container

tom.wilkie · February 16, 2025, 8:39pm

Hi there!

I’m developing an addon for monitoring your home assistant box using Grafana and Prometheus; part of this is installing things like node-exporter and cAdvisor to collect all the metrics about the host. And part of that is needing access to the hosts /proc and /sys filesystems - is there a way to mount them into the add on container?

Cheers

Tom

I’ve seen an existing add on for node exporter (hassos-addons/prometheus_node_exporter at 705aeaa4c48b619da286ba8802c4e8d8b6c56254 · loganmarchione/hassos-addons · GitHub) that doesn’t get /proc and /sys access, and the problem is this leads to a bunch of miss-reported metrics, not least the hostname. And no, using the host PID namespace doesn’t fix this.

tom.wilkie · February 17, 2025, 8:58am

Looks like this can’t be done as-is; do you think the maintainers would be open to adding “sys” and “proc” mounts for add ons? The code is here supervisor/supervisor/docker/addon.py at 4c108eea6411df12e9292e4171c1ca2c8d8b129f · home-assistant/supervisor · GitHub, I think I could probably put something together…

roippi · March 7, 2025, 10:40pm

+1, I just ran into this while making a datadog agent add-on. There is no way currently to mount /proc and /sys/fs/cgroup, specifically, into the agent container, which enables various monitoring capabilities.

I would like a way to enable this in config, even if it requires turning off every single security flag.

Happy to contribute a PR if maintainers can weigh in on if such a thing would be acceptable.