Spearhead

A 2015 MacBook Air with a dead battery, repurposed as a headless Ubuntu home server.

What it runs

• Pi-hole v6 for network-wide DNS filtering, so ads and trackers are blocked at the router level for every device on the network.
• Tailscale, configured as an exit node, so the same filtering and a private route home follow the network off-site.
• PdfDing for a self-hosted PDF reading/annotation library.
• A handful of cron jobs for backups and health checks, reported over Tailscale rather than exposed to the open internet.

Nothing on the box is reachable except through the Tailscale mesh — no open ports facing the public internet.