pez-infra/docs/hosts/london-c.md

london-c

Raspberry Pi at the London site. Edge utility box for lightweight workloads that don't justify spinning up the Threadripper.

Overview

Location	London (NW9)
OS	Debian 13 (Trixie), aarch64
Tailscale IP	100.123.72.87
Role	Octopus Energy exporter, general-purpose Pi
Form factor	Raspberry Pi (ARM64)

Services

Service	Port	Deployment	Notes
octopus_exporter	9359	Docker (rwejlgaard/octopus_exporter)	Pulls electricity-usage data from the Octopus Energy API; scraped by Alloy
Tailscale	—	Native	Mesh networking
Docker / containerd	—	Native	For octopus-exporter
Alloy	—	Native (Ansible-managed)	Ships metrics/logs to Grafana Cloud
node_exporter	9100	Native	Host metrics
systemd_exporter	—	Native	systemd unit metrics
fail2ban	—	Native	SSH brute-force protection

Compose file lives at ansible/services/octopus-exporter/docker-compose.yml. The OCTOPUS_API_KEY is templated in from a SOPS-encrypted variable.

Networking

Connected via Ethernet to the Ubiquiti switch alongside london-a and london-b.

Notes

• Single-board-computer form factor — runs cool, draws ~5 W, lives on the rack shelf without active cooling.
• A natural place to park future "small but always-on" workloads (sensors, cron jobs, smart-home glue) that don't need to share fate with london-b.