Make it stop

experimental/tracer/main/main.go

@@ -24,6 +24,13 @@ type tracer struct {
 	docker docker.Registry
 }
 
+func (t *tracer) Stop() {
+	log.Printf("Shutting down...")
+	t.ptrace.Stop()
+	t.docker.Stop()
+	log.Printf("Done.")
+}
+
 func main() {
 	dockerRegistry, err := docker.NewRegistry(pollInterval)
 	if err != nil {
@@ -35,20 +42,28 @@ func main() {
 		store:  newStore(),
 		docker: dockerRegistry,
 	}
+	defer tracer.Stop()
+
 	go tracer.http(6060)
-	handleSignals()
+	<-handleSignals()
 }
 
-func handleSignals() {
-	sigs := make(chan os.Signal, 1)
-	signal.Notify(sigs, syscall.SIGQUIT)
-	buf := make([]byte, 1<<20)
-	for {
-		sig := <-sigs
-		switch sig {
-		case syscall.SIGQUIT:
-			stacklen := runtime.Stack(buf, true)
-			log.Printf("=== received SIGQUIT ===\n*** goroutine dump...\n%s\n*** end\n", buf[:stacklen])
+func handleSignals() chan struct{} {
+	quit := make(chan struct{}, 10)
+	go func() {
+		sigs := make(chan os.Signal, 1)
+		signal.Notify(sigs, syscall.SIGQUIT, syscall.SIGINT, syscall.SIGTERM)
+		buf := make([]byte, 1<<20)
+		for {
+			sig := <-sigs
+			switch sig {
+			case syscall.SIGINT, syscall.SIGTERM:
+				quit <- struct{}{}
+			case syscall.SIGQUIT:
+				stacklen := runtime.Stack(buf, true)
+				log.Printf("=== received SIGQUIT ===\n*** goroutine dump...\n%s\n*** end\n", buf[:stacklen])
+			}
 		}
-	}
+	} ()
+	return quit
 }

experimental/tracer/ptrace/ptracer.go

@@ -52,6 +52,21 @@ func NewPTracer() PTracer {
 	return t
 }
 
+func (t *PTracer) Stop() {
+	out := make(chan []int)
+	t.ops <- func() {
+		pids := []int{}
+		for pid := range t.processes {
+			pids = append(pids, pid)
+		}
+		out <- pids
+	}
+	for _, pid := range <-out {
+		t.StopTracing(pid)
+	}
+	t.quit <- struct{}{}
+}
+
 // TraceProcess starts tracing the given pid
 func (t *PTracer) TraceProcess(pid int) *process {
 	result := make(chan *process)
@@ -149,7 +164,10 @@ func (t *PTracer) traceThread(pid int, process *process) *thread {
 
 		t.threads[pid] = thread
 		result <- thread
-		t.childAttached <- struct{}{}
+		select {
+		case t.childAttached <- struct{}{}:
+		default:
+		}
 	}
 	return <-result
 }
@@ -162,19 +180,20 @@ func (t *PTracer) waitLoop() {
 	)
 
 	for {
+		log.Printf("Waiting...")
 		pid, err = syscall.Wait4(-1, &status, syscall.WALL, nil)
 		if err != nil && err.(syscall.Errno) == syscall.ECHILD {
-			log.Printf("No children to wait4")
+			log.Printf( "No children to wait4")
 			<-t.childAttached
 			continue
 		}
 
 		if err != nil {
-			log.Printf("Wait failed: %v %d", err, err.(syscall.Errno))
+			log.Printf(" Wait failed: %v %d", err, err.(syscall.Errno))
 			return
 		}
 
-		log.Printf("PID %d stopped", pid)
+		log.Printf(" PID %d stopped with signal %#x", pid, status)
 		t.stopped <- stopped{pid, status}
 	}
 }
@@ -235,6 +254,7 @@ func (t *PTracer) handleStopped(pid int, status syscall.WaitStatus) {
 	}
 
 	// Restart stopped caller in syscall trap mode.
+	log.Printf("Restarting pid %d with signal %d", pid, int(signal))
 	err = syscall.PtraceSyscall(pid, int(signal))
 	if err != nil {
 		log.Printf("PtraceSyscall failed, pid=%d, err=%v", pid, err)

experimental/tracer/tracer

@@ -16,11 +16,8 @@ shift 1
 case "$COMMAND" in
 
     launch)
-        docker run --privileged --net=host --pid=host -d -v /var/run/docker.sock:/var/run/docker.sock \
+        docker run --privileged --net=host --pid=host -ti -v /var/run/docker.sock:/var/run/docker.sock \
             --name $CONTAINER_NAME weaveworks/tracer
-        for ip in $(hostname -I); do
-            echo http://$ip:6060
-        done
         ;;
 
     stop)

experimental/tracer/ui/index.html

@@ -21,14 +21,29 @@
       var containers = {};
       var traces = {}
 
-      $.get("/containers").done(function (data) {
-        $.each(data, function(i, container) {
-          containers[container.Id] = container
-          $("ol.containers").append(sprintf("<li id='%s'>%s</li>", container.Id, container.Name))
-        });
-      });
+      function updateContainers() {
+          $.get("/containers").done(function (data) {
+            $("ul.containers").html("")
+            data.sort(function (a, b) {
+                if (a.Name > b.Name) {
+                    return 1;
+                }
+                if (a.Name < b.Name) {
+                    return -1;
+                }
+                // a must be equal to b
+                return 0;
+            });
+            $.each(data, function(i, container) {
+              containers[container.Id] = container
+              $("ul.containers").append(sprintf("<li id='%s'>%s</li>", container.Id, container.Name.substring(1)))
+            });
+            window.setTimeout(updateContainers, 5 * 1000)
+          });
+      }
+      updateContainers()
 
-      $("ol.containers").on("click", "li", function() {
+      $("ul.containers").on("click", "li", function() {
         var container = containers[$(this).attr("id")]
         var containerTraces = traces[$(this).attr("id")] || []
 
@@ -56,7 +71,7 @@
     </script>
 
     <style>
-      ol.containers li {
+      ul.containers li {
         cursor: pointer;
       }
     </style>
@@ -86,8 +101,8 @@
     <div class="container-fluid">
       <div class="col-md-4">
         <h1>Weave Tracer</h1>
-        <ol class="containers">
-        </ol>
+        <ul class="containers">
+        </ul>
       </div>
 
       <div class="col-md-8 mainview">