4989513a96
The cgroup-only approach was a no-op on the demo: the controller container's OWN cgroup is unlimited (the 2GB cap is on the LXC ancestor, hidden), and /proc has no lxcfs, so it kept reporting the host's 16GB. The Docker daemon runs IN the LXC, so 'docker info' MemTotal reports the guest's real cap (2048MB) — now the authoritative source (cgroup limit preferred when present, e.g. non-nested). The deploy memory guard now uses the controller's committed-app memory (sum of running mem requests) for 'used' — accurate and cheap — instead of host /proc RSS (unobservable per guest; would make the guard never/always fire). /api/system/info reports the guest cap as total and committed memory as used. Tests: cgroup-limit path, docker-info fallback (nested case), GuestMemTotalMB fallback (dockerMemTotalFn stub).