12f6e6be51
The proxy now supports OVERPASS_URLS (comma-separated, round-robin fallback) with OVERPASS_URL as a single-entry backward-compat alias; update the switch path note to match. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
54 lines
2.6 KiB
Markdown
54 lines
2.6 KiB
Markdown
# self-host-overpass (parked)
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Full OpenSpec artifact set (`proposal.md`, `design.md`, `specs/`, `tasks.md`)
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for hosting our own Overpass API. Moved here from `openspec/changes/` so it
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does not clutter the active change list; revive by moving the directory back
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under `openspec/changes/` when ready to implement.
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## Status
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**Parked.** The interim proxy work (`/api/overpass` → `overpass.private.coffee`,
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see `apps/planner/app/routes/api.overpass.ts`) covers the day-one needs:
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User-Agent compliance, same-origin check, rate limiting, server-side cache
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with coalescing, bbox quantization, Grafana observability. That buys us time
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before we need to own the upstream.
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## When to revive
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Revisit once **any** of these is true:
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- private.coffee rate-limits our traffic or changes policy
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- Our query volume makes continued use of a free public instance feel like
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abuse (rule of thumb: >1 req/s sustained)
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- We want POI coverage outside regions private.coffee happens to import
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- Privacy posture requires full control of the upstream
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## Key decisions already made
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- **Topology**: Overpass runs on the maintainer's second Hetzner box
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(FSN1, dedicated, i7-2600, 32 GB, 2×3 TB HDD, 1.8 TB free). Both hosts
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share Hetzner's internal backbone with ~1 ms RTT.
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- **Access control**: host-level firewall via nftables `DOCKER-USER` chain
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(Docker bypasses `INPUT` when publishing ports, which is the classic
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gotcha). Only the Planner host's egress IP is allowed on the Overpass
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port. Planner host IP lives in `/etc/overpass/planner-ip.env` on the
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Overpass box, **not** in the repo. Tailscale / WireGuard / vSwitch kept
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as future hardening options.
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- **Capacity ceiling on current hardware**: DACH extract fits comfortably
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in the 23 GB of RAM available on the Overpass box. Europe+ would need
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different hardware (AX52 ≈ €54/mo for a dedicated 64 GB NVMe box that
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handles planet at low user counts; see design.md).
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- **Switch path**: no client changes needed to cut over — the Planner
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proxy reads `OVERPASS_URLS` (comma-separated list with round-robin
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fallback) or the single-entry alias `OVERPASS_URL`, defaulting to
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`lz4.overpass-api.de` then `overpass-api.de`. Flipping the env var
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points at our own instance.
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## What's in the folder
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- `proposal.md` — why / what / impact
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- `design.md` — topology, firewall pattern, capacity analysis, risks
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- `specs/` — delta specs (would land against `overpass-hosting`,
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`osm-poi-overlays`, `infrastructure`, `rate-limiting`)
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- `tasks.md` — 10 groups of implementation tasks
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- `.openspec.yaml` — OpenSpec scaffolding; keep for when it comes back
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