# ADR 0001 — Single bare-metal host, Docker Compose per customer

**Status:** Accepted

## Context
Small hosting business, modest site count, ZFS-based backup strategy. Options
ranged from a single host to a multi-host orchestrated fleet (Swarm/Nomad/k8s)
or cloud VMs.

## Decision
Run everything on **one bare-metal host**, using **one Docker Compose project
per customer/site**. No orchestrator. Host configured with Ansible.

## Consequences
- ✅ Simplest possible operational model; ZFS lives directly on local disks
  (best snapshot/`send` story, no network-storage complications).
- ✅ Compose-per-customer maps 1:1 to the isolation and backup boundary.
- ✅ No control-plane overhead (no etcd, no scheduler).
- ❌ No built-in HA/failover; the host is a single point of failure — mitigated
  by disciplined offsite backups and a documented rebuild/restore drill.
- ❌ Vertical scaling only. If site count outgrows one box, revisit with a
  superseding ADR (Swarm/Nomad, ZFS locality becomes the hard problem).