chore: import upstream snapshot with attribution

cmd/gortex/daemon_pprof.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"net"
+	"net/http"
+	_ "net/http/pprof" // registers /debug/pprof/* on http.DefaultServeMux
+	"os"
+	"sync/atomic"
+
+	"go.uber.org/zap"
+)
+
+// pprofAddr holds the bound address of the daemon's pprof listener
+// (empty when pprof is disabled). Read by controller.Status so the
+// active address is reported to clients; written exactly once from
+// startPProfIfEnabled. atomic.Value guards against the data race that
+// would otherwise exist between Status calls and startup.
+var pprofAddr atomic.Value
+
+func init() {
+	pprofAddr.Store("")
+}
+
+// daemonPProfAddr returns the currently-bound pprof listener address,
+// or an empty string when no listener is running.
+func daemonPProfAddr() string {
+	v, _ := pprofAddr.Load().(string)
+	return v
+}
+
+// startPProfIfEnabled opens an HTTP pprof listener when the user has
+// set GORTEX_DAEMON_PPROF_ADDR (e.g. "127.0.0.1:6060"). Opt-in by
+// design — leaving a pprof endpoint on by default would expose the
+// daemon's internal state to any process on the machine. The listener
+// runs in its own goroutine; failures are logged but don't block
+// daemon startup.
+func startPProfIfEnabled(logger *zap.Logger) {
+	addr := os.Getenv("GORTEX_DAEMON_PPROF_ADDR")
+	if addr == "" {
+		return
+	}
+	ln, err := net.Listen("tcp", addr)
+	if err != nil {
+		logger.Warn("daemon: pprof listener failed",
+			zap.String("addr", addr), zap.Error(err))
+		return
+	}
+	bound := ln.Addr().String()
+	pprofAddr.Store(bound)
+	logger.Info("daemon: pprof endpoint open",
+		zap.String("addr", bound),
+		zap.String("hint", "go tool pprof -http=: http://"+bound+"/debug/pprof/heap"))
+	go func() {
+		// Serve on the DefaultServeMux which net/http/pprof registers on.
+		if err := http.Serve(ln, nil); err != nil && err != http.ErrServerClosed {
+			logger.Warn("daemon: pprof serve exited", zap.Error(err))
+		}
+	}()
+}