Per-container CPU/memory was invisible for the quadlet app stack — Grafana could
only see the host (node_exporter) and the LLM engines. This adds a rootless
cadvisor quadlet on each host and a `containers` dashboard.
cadvisor works on this rootless-Podman / cgroup-v2 host on one condition:
--cgroupns=host. Podman starts every container in a private cgroup namespace, so
without it cadvisor sees only its own cgroup root and exports a single series
(measured 2026-10-20: 1 series off, 996 on). The libpod socket does not name the
rootless app containers (it resolved 2 of 34), so naming comes from elsewhere:
the quadlet unit name is carried in the cgroup path
(app.slice/<name>.service/libpod-payload-<hex>), and Prometheus relabels it into
a `container` label. No podman socket needed.
cadvisor cannot bind per-interface like node_exporter, so each unit is a bridge
container publishing exactly 127.0.0.1:8080 and the host LAN address — never a
wildcard. Prometheus (a bridge container) reaches a host-published port at the
LAN address, so cadvisor-dankclaw/dankserver scrape 192.168.0.143:8080 /
192.168.0.235:8080. Only the families cadvisor actually exports for these
containers are graphed — CPU usage, memory working-set/limit, OOM — not network
or filesystem, which are absent under the host-PID layout.
Wired through the deployer (allowlist, deploy_observability case + /healthz gate,
dispatcher), the planner (both targets), and observability_quadlet.bats.
Frank
31908c623f