fix: graceful shutdown, L7 panic protection, bounded cache

containers/registry.go

@@ -403,6 +403,11 @@ func (r *Registry) handleEvents(ch <-chan ebpftracer.Event) {
 const maxIP2FQDNEntries = 10000
 
 func (r *Registry) processL7Event(e ebpftracer.Event) {
+	defer func() {
+		if p := recover(); p != nil {
+			klog.Errorf("recovered from panic in L7 event handler: pid=%d fd=%d protocol=%d: %v", e.Pid, e.Fd, e.L7Request.Protocol, p)
+		}
+	}()
 	if c := r.containersByPid[e.Pid]; c != nil {
 		klog.V(5).Infof("L7_EVENT_CONTAINER_FOUND: pid=%d container=%s", e.Pid, c.id)
 		ip2fqdn, result := c.onL7RequestWithResult(e.Pid, e.Fd, e.Timestamp, e.L7Request, e.SocketInfo)
@@ -491,7 +496,10 @@ func (r *Registry) processPendingL7Events() {
 			continue
 		}
 
-		ip2fqdn, result := c.onL7RequestWithResult(p.event.Pid, p.event.Fd, p.event.Timestamp, p.event.L7Request, p.event.SocketInfo)
+		ip2fqdn, result, panicked := r.safeOnL7Request(c, p.event)
+		if panicked {
+			continue
+		}
 		if result == L7RequestConnNotFound {
 			// Still not found - keep in queue if not exceeded max retries
 			if p.retryCount < maxRetries {
@@ -521,6 +529,17 @@ func (r *Registry) processPendingL7Events() {
 	}
 }
 
+func (r *Registry) safeOnL7Request(c *Container, e ebpftracer.Event) (ip2fqdn map[netaddr.IP]*common.Domain, result L7RequestResult, panicked bool) {
+	defer func() {
+		if p := recover(); p != nil {
+			klog.Errorf("recovered from panic in pending L7 retry: pid=%d fd=%d protocol=%d: %v", e.Pid, e.Fd, e.L7Request.Protocol, p)
+			panicked = true
+		}
+	}()
+	ip2fqdn, result = c.onL7RequestWithResult(e.Pid, e.Fd, e.Timestamp, e.L7Request, e.SocketInfo)
+	return
+}
+
 func (r *Registry) getOrCreateContainer(pid uint32) *Container {
 	// Fast path: try to find existing container with read lock
 	lockStart := time.Now()

ebpftracer/tls.go

@@ -10,12 +10,12 @@ import (
 	"os"
 	"regexp"
 	"strings"
-	"sync"
 	"unsafe"
 
 	"github.com/cilium/ebpf/link"
 	"github.com/coroot/coroot-node-agent/common"
 	"github.com/coroot/coroot-node-agent/proc"
+	lru "github.com/hashicorp/golang-lru/v2"
 	"k8s.io/klog/v2"
 )
 
@@ -53,8 +53,9 @@ var (
 
 	// strippedGoExeCache caches exe paths that are Go binaries but have no TLS symbols.
 	// This avoids expensive ELF scanning for the same stripped binary across many
-	// short-lived processes (e.g., kubectl invocations). Uses sync.Map for lock-free reads.
-	strippedGoExeCache = &sync.Map{} // map[string]struct{}
+	// short-lived processes (e.g., kubectl invocations). Capped at 1000 entries to
+	// prevent unbounded growth on CI/CD nodes with many unique Go binaries.
+	strippedGoExeCache, _ = lru.New[string, struct{}](1000)
 )
 
 func (t *Tracer) AttachOpenSslUprobes(pid uint32) []link.Link {
@@ -181,7 +182,7 @@ func (t *Tracer) AttachGoTlsUprobes(pid uint32) ([]link.Link, bool) {
 
 	// Skip binaries we already know are stripped (no TLS symbols).
 	// This avoids expensive ELF scanning for repeated short-lived processes like kubectl.
-	if _, stripped := strippedGoExeCache.Load(exeName); stripped {
+	if strippedGoExeCache.Contains(exeName) {
 		klog.V(3).Infof("GO_TLS_SKIP_STRIPPED: pid=%d exe=%s", pid, exeName)
 		return nil, true // still a Go app, just stripped
 	}
@@ -258,7 +259,7 @@ func (t *Tracer) AttachGoTlsUprobes(pid uint32) ([]link.Link, bool) {
 				log("failed to get write symbol", err)
 				// Cache this exe as stripped to skip future attempts
 				if exeName != "" {
-					strippedGoExeCache.Store(exeName, struct{}{})
+					strippedGoExeCache.Add(exeName, struct{}{})
 				}
 				return nil, isGolangApp
 			}

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"context"
 	"flag"
 	"fmt"
 	"log"
@@ -163,16 +164,16 @@ func main() {
 	if err != nil {
 		klog.Errorf("Error starting resolver: %v", err)
 	}
+	defer resolver.StopWatching()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
 	go func() {
 		sigChannel := make(chan os.Signal, 1)
-		defer close(sigChannel)
-
 		signal.Notify(sigChannel, os.Interrupt, syscall.SIGTERM)
 		<-sigChannel
-
 		klog.Infoln("Received signal, shutting down")
-		resolver.StopWatching()
-		os.Exit(0) // Ensure graceful termination
+		cancel()
 	}()
 	hostname, kv, err := uname()
 	if err != nil {
@@ -252,8 +253,21 @@ func main() {
 		"Metrics collection timeout",
 	))
 
+	srv := &http.Server{Addr: *flags.ListenAddress}
+	go func() {
+		<-ctx.Done()
+		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer shutdownCancel()
+		if err := srv.Shutdown(shutdownCtx); err != nil {
+			klog.Errorf("HTTP server shutdown error: %v", err)
+		}
+	}()
+
 	klog.Infoln("listening on:", *flags.ListenAddress)
-	klog.Errorln(http.ListenAndServe(*flags.ListenAddress, nil))
+	if err := srv.ListenAndServe(); err != http.ErrServerClosed {
+		klog.Errorln(err)
+	}
+	klog.Infoln("shutdown complete")
 }
 
 func info(name, version string) prometheus.Collector {