fix(mempool): self-healing nginx backend proxy (v3.0.1) + gate timeout

lfg2025/archy

The frontend nginx used a literal proxy_pass host with no resolver, so it
pinned mempool-api's IP at worker startup. When the backend restarts (gate,
OTA, crash, reboot re-IPAM) podman reassigns its IP and nginx keeps proxying
to the dead one -> /api hangs, websocket 502s, UI shows 'offline' until a
manual nginx reload. Same stale-upstream-IP class as the netbird 502.

Fix: mempool-frontend:v3.0.1 rewrites the generated nginx-mempool.conf to
re-resolve the backend per-request via 'resolver' + a variable proxy_pass.
Resolver address is read from /etc/resolv.conf (podman aardvark-dns answers
on the network gateway, not Docker's 127.0.0.11). Per-location path mapping
preserved (ws -> '/', /api/v1 identity via no-URI, /api/ -> /api/v1/ rewrite).
Proven on .228: backend IP change now auto-recovers with no reload; the
literal-host control still 502s. Migrated the manifest off the retired
tx1138 registry to vps2.

Also: mempool.bats #74 waited only 180s post-restart (the slow path) and
called an undefined 'fail' helper (status 127). Bumped to 300s to match the
passing parity probes and emit a real failure instead.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

This commit is contained in:

archipelago

2026-06-22 18:07:07 -04:00

co-authored by

Claude Opus 4.8

parent c8acc84506

commit 0f05f73a23

8 changed files with 167 additions and 8 deletions

									
										scripts/image-versions.sh
									
		+1
		-1
	
												View File
												
				@@ -20,7 +20,7 @@ ELECTRUMX_IMAGE="$ARCHY_REGISTRY/electrumx:v1.18.0"

				# Mempool stack

				MEMPOOL_BACKEND_IMAGE="$ARCHY_REGISTRY/mempool-backend:v3.0.0"

				MEMPOOL_WEB_IMAGE="$ARCHY_REGISTRY/mempool-frontend:v3.0.0"

				MEMPOOL_WEB_IMAGE="$ARCHY_REGISTRY/mempool-frontend:v3.0.1"

				MARIADB_IMAGE="$ARCHY_REGISTRY/mariadb:11.4.10"

				# BTCPay