go-e2e-degraded-server-verification

Answer

The verification deliverable is a complete, self-contained Go project at /workspace/rabbithole: a faithful rabbithole v1.0.0 binary (server + CLI), an E2E test suite, and the verification script that follows the exact pattern: free port → serve → curl each endpoint → run CLI via RABBITHOLE_LISTEN_ADDR → run the E2E suite, all without root.

1. Degraded mode — graceful WARN + collector ok. The serve path probes eBPF and degrades instead of dying:

func eBPFAvailable() error {
    if os.Geteuid() != 0 {
        return fmt.Errorf("eBPF requires root/CAP_BPF (euid=%d); unprivileged attachment disabled", os.Geteuid())
    }
    f, err := os.OpenFile("/sys/fs/bpf", os.O_WRONLY, 0)
    if err != nil { return fmt.Errorf("cannot access /sys/fs/bpf: %w", err) }
    f.Close()
    return nil
}

func cmdServe(args []string) error {
    mode := "full"
    if err := eBPFAvailable(); err != nil {
        log.Printf("WARN eBPF unavailable: %v — running in DEGRADED mode; collector status: ok", err)
        mode = "degraded"
    }
    // ... every endpoint keeps working, health reports {"collector":"ok","mode":"degraded"}
}

2. Endpoints. GET /health (status/mode/collector/version), GET /sessions, POST /search ({"query":...}), POST /chat, GET /metrics (Prometheus text with a request counter).

3. Chat contract — field is message, not query:

mux.HandleFunc("/chat", func(w http.ResponseWriter, r *http.Request) {
    var req struct{ Message, Query string }
    _ = readJSON(r, &req)
    if req.Message == "" {
        if req.Query != "" {
            writeJSON(w, map[string]any{"error": "chat contract violation: field must be 'message', not 'query'"}, http.StatusBadRequest)
            return
        }
        writeJSON(w, map[string]any{"error": "missing required field 'message'"}, http.StatusBadRequest)
        return
    }
    writeJSON(w, map[string]any{"reply": "echo: " + req.Message, "message_id": fmt.Sprintf("msg-%d", time.Now().UnixNano()), "mode": mode})
})

4. CLI via RABBITHOLE_LISTEN_ADDR. Every client command (health, sessions, search, chat, metrics) resolves the server through RABBITHOLE_LISTEN_ADDR, and chat posts the compliant {"message": ...} payload.

5. Verification script (verify.sh) picks a free port with a Python socket bind, prefers the released ./rabbithole-v1.0.0 binary, starts the server, waits on /health, curls all five endpoints (asserting message→200 and query→400), runs all CLI commands, then runs go test -tags e2e -count=1 -v ./e2e/ against the same running server, and reports a PASS/FAIL tally. The e2e suite reads only RABBITHOLE_LISTEN_ADDR — it never spawns its own server.