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fix: watchdog DNS tolerance + pg_isready in wait-service - #4
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…wait-service Watchdog was too aggressive — single nslookup failure (transient CoreDNS hiccup, network blip) triggered tunnel kill and unnecessary re-provisioning. Now requires 3 consecutive DNS failures before killing the tunnel. wait-service was checking only TCP port 5432 (nc -z), not PostgreSQL readiness. PostgreSQL from snapshot needs WAL recovery time — TCP port opens before PostgreSQL accepts connections. Now uses pg_isready to wait for actual PostgreSQL readiness, not just TCP port.
This was referenced Jul 29, 2026
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Problem
Two issues found after PR #3 (retry-loop re-provisioning):
1. Watchdog too aggressive (false positive re-provisioning)
Watchdog checked
nslookupevery 10s and killed the tunnel on first DNS failure. Butnslookupcan transiently fail (CoreDNS restart, network blip, DNS cache miss) even when the upstream workflow is alive. This caused unnecessary re-provisioning — client didn't crash, but watchdog killed the tunnel and ordered a new DB.Fix: Require 3 consecutive DNS failures before killing the tunnel (30s of continuous DNS failure = real deletion, not transient).
2. wait-service checks TCP port, not PostgreSQL readiness
wait-serviceusednc -z(TCP port check) — but PostgreSQL from snapshot needs WAL recovery time. TCP port 5432 opens before PostgreSQL accepts connections. Client connects, getswebsocket: close 1005for minutes until PostgreSQL is ready.Fix: Use
pg_isready(PostgreSQL-native readiness check) after TCP port is open. Changed image fromalpinetopostgres:17-alpine(haspg_isready).Testing