Phase 8 second commit. TCP listener orchestration + per-connection
business logic.
server.go (~70 LOC):
- mysql.Run(ctx, addr, ConnectionHandler) error
Listens via net.ListenConfig (context-aware), accepts in a loop,
dispatches each connection to handler.HandleConnection in its own
goroutine, waits on context cancellation to close the listener
and drain in-flight connections via WaitGroup
- ConnectionHandler interface (single HandleConnection method) so
tests can substitute a stub without standing up real handler deps
- Logs listener bind + accept errors via slog; suppresses net.ErrClosed
on graceful shutdown so the shutdown path is silent
handler.go (~170 LOC):
- TokenLookup interface (GetByID) and EventRecorder interface (Record)
decouple the handler from Phase 9's token.Service and Phase 10's
event.Service. Production wire-up in Phase 9 (deferred — see Phase
8 rollup notes on task 8.5 deferral)
- HandleConnection writes HandshakeV10 → reads HandshakeResponse41 →
extracts username → strips canary_ prefix → looks up token →
records event with mysql_username + mysql_client_capabilities +
mysql_client_charset in event.Extra (mirrors kubeconfig's
kubectl_* forensic capture) → writes ERR_Packet 1045 → defers
close. 10-second connection deadline.
- Defense-in-depth: usernames without canary_ prefix dropped
silently, unknown tokens dropped silently, lookup errors dropped
silently — no behavior signal to a probing attacker
- Nil EventRecorder tolerated (writes ERR but skips event) — Phase 9
can wire the handler before event.Service exists if needed
Tests (~14 cases):
- server: nil-handler rejected, basic dispatch, 10 concurrent
connections, context cancellation closes listener cleanly,
invalid address rejected
- handler: handshake sent first, non-canary username drops silently,
known token records event AND sends ERR, event.Extra carries
all three kubectl-equivalent fields with correct hex formatting,
unknown token records nothing, lookup error silent, nil
EventRecorder tolerated (still sends ERR), bad auth packet
silent
- Uses real net.Listener + net.Conn pairs (not mocks) for
behavioral fidelity — TCP wire-protocol tests should hit real
sockets
go test -race -timeout=60s passes. golangci-lint clean.
4d4d4951ba