Merge pull request #2366 from kinvolk/schu/ebpf-stop-tracker

endpoint/ebpf: implement stop

probe/endpoint/ebpf.go

@@ -209,15 +209,8 @@ func (t *EbpfTracker) isDead() bool {
 }
 
 func (t *EbpfTracker) stop() {
-	// TODO: implement proper stopping logic
-	//
-	// Even if we stop the go routine, it's not enough since we disabled the
-	// async proc parser. We leave this uninmplemented for now because:
-	//
-	// * Ebpf parsing is optional (need to be enabled explicitly with
-	// --probe.ebpf.connections=true), if a user enables it we assume they
-	// check on the logs whether it works or not
-	//
-	// * It's unlikely that the ebpf tracker stops working if it started
-	// successfully and if it does, we probaby want it to fail hard
+	if t.tracer != nil {
+		t.tracer.Stop()
+	}
+	t.dead = true
 }

vendor/github.com/weaveworks/tcptracer-bpf/pkg/tracer/tracer.go

@@ -13,6 +13,7 @@ type Tracer struct {
 	m           *bpflib.Module
 	perfMapIPV4 *bpflib.PerfMap
 	perfMapIPV6 *bpflib.PerfMap
+	stopChan    chan struct{}
 }
 
 func TracerAsset() ([]byte, error) {
@@ -61,17 +62,27 @@ func NewTracer(tcpEventCbV4 func(TcpV4), tcpEventCbV6 func(TcpV6)) (*Tracer, err
 	perfMapIPV4.SetTimestampFunc(tcpV4Timestamp)
 	perfMapIPV6.SetTimestampFunc(tcpV6Timestamp)
 
+	stopChan := make(chan struct{})
+
 	go func() {
 		for {
-			data := <-channelV4
-			tcpEventCbV4(tcpV4ToGo(&data))
+			select {
+			case <-stopChan:
+				return
+			case data := <-channelV4:
+				tcpEventCbV4(tcpV4ToGo(&data))
+			}
 		}
 	}()
 
 	go func() {
 		for {
-			data := <-channelV6
-			tcpEventCbV6(tcpV6ToGo(&data))
+			select {
+			case <-stopChan:
+				return
+			case data := <-channelV6:
+				tcpEventCbV6(tcpV6ToGo(&data))
+			}
 		}
 	}()
 
@@ -82,10 +93,12 @@ func NewTracer(tcpEventCbV4 func(TcpV4), tcpEventCbV6 func(TcpV6)) (*Tracer, err
 		m:           m,
 		perfMapIPV4: perfMapIPV4,
 		perfMapIPV6: perfMapIPV6,
+		stopChan:    stopChan,
 	}, nil
 }
 
 func (t *Tracer) Stop() {
+	close(t.stopChan)
 	t.perfMapIPV4.PollStop()
 	t.perfMapIPV6.PollStop()
 }

vendor/manifest

@@ -1454,7 +1454,7 @@
 			"importpath": "github.com/weaveworks/tcptracer-bpf",
 			"repository": "https://github.com/weaveworks/tcptracer-bpf",
 			"vcs": "git",
-			"revision": "9065e4672b606b5f8d2f2d664938641fa0ee0d0f",
+			"revision": "d4a42f2cc89eb19e60113f7e35945a29b97c695f",
 			"branch": "master",
 			"notests": true
 		},