london-b had both a custom node_exporter.service and the
package-managed prometheus-node-exporter.service installed.
Both tried to bind port 9100, causing the package version to fail.
- Add cleanup tasks to remove custom /etc/systemd/system/node_exporter.service
and /usr/local/bin/node_exporter if present
- Add node_exporter_extra_collectors variable for configurable collectors
- Configure london-b with systemd/processes/sysctl/ethtool/zfs collectors
matching its previous custom setup
Resolves PESO-109
node_exporter was listening on 0.0.0.0:9100 on helsinki-a and london-a,
exposing metrics to the public internet.
Changes:
- Add node_exporter_bind_tailscale flag (default false) to opt in
- Set flag on helsinki-a and london-a host_vars
- Debian: configure ARGS in /etc/default/prometheus-node-exporter
- FreeBSD: use native node_exporter_listen_address rc.conf variable
- Add handlers to restart on config change
Prometheus already scrapes via Tailscale IPs, no scrape config changes needed.
Fixes PESO-98
