Trace all processes in a container.

experimental/example/app/app.py

@@ -46,13 +46,8 @@ def ignore_error(f):
 
 @app.route('/')
 def hello():
-  counter_future = pool.submit(do_redis)
-  search_future = pool.submit(do_search)
-  qotd_future = pool.submit(do_qotd)
-  result = 'Hello World! I have been seen %s times.' % ignore_error(counter_future.result)
-  result += ignore_error(search_future.result)
-  result += ignore_error(qotd_future.result)
-  return result
+  qotd_msg = do_qotd()
+  return qotd_msg
 
 if __name__ == "__main__":
   logging.basicConfig(format='%(asctime)s %(levelname)s %(filename)s:%(lineno)d - %(message)s', level=logging.INFO)

experimental/tracer/main/http.go

@@ -11,6 +11,7 @@ import (
 	dockerClient "github.com/fsouza/go-dockerclient"
 
 	"github.com/weaveworks/scope/probe/docker"
+	"github.com/weaveworks/scope/probe/process"
 )
 
 func respondWith(w http.ResponseWriter, code int, response interface{}) {
@@ -23,10 +24,30 @@ func respondWith(w http.ResponseWriter, code int, response interface{}) {
 	}
 }
 
+func (t *tracer) pidsForContainer(id string) ([]int, error) {
+	var container docker.Container
+	t.docker.WalkContainers(func(c docker.Container) {
+		if c.ID() == id {
+			container = c
+		}
+	})
+
+	if container == nil {
+		return []int{}, fmt.Errorf("Not Found")
+	}
+
+	pidTree, err := process.NewTree(process.NewWalker("/proc"))
+	if err != nil {
+		return []int{}, err
+	}
+
+	return pidTree.GetChildren(container.PID())
+}
+
 func (t *tracer) http(port int) {
 	router := mux.NewRouter()
 
-	router.Methods("GET").Path("/containers").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+	router.Methods("GET").Path("/container").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		containers := []*dockerClient.Container{}
 		t.docker.WalkContainers(func(container docker.Container) {
 			containers = append(containers, container.Container())
@@ -35,6 +56,34 @@ func (t *tracer) http(port int) {
 		respondWith(w, http.StatusOK, containers)
 	})
 
+	router.Methods("POST").Path("/container/{id}").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		id := mux.Vars(r)["id"]
+		children, err := t.pidsForContainer(id)
+		if err != nil {
+			respondWith(w, http.StatusBadRequest, err.Error())
+			return
+		}
+
+		for _, pid := range children {
+			t.ptrace.TraceProcess(pid)
+		}
+		w.WriteHeader(204)
+	})
+
+	router.Methods("DELETE").Path("/container/{id}").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		id := mux.Vars(r)["id"]
+		children, err := t.pidsForContainer(id)
+		if err != nil {
+			respondWith(w, http.StatusBadRequest, err.Error())
+			return
+		}
+
+		for _, pid := range children {
+			t.ptrace.StopTracing(pid)
+		}
+		w.WriteHeader(204)
+	})
+
 	router.Methods("GET").Path("/pid").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		respondWith(w, http.StatusOK, t.ptrace.AttachedPIDs())
 	})
@@ -61,6 +110,8 @@ func (t *tracer) http(port int) {
 		w.WriteHeader(204)
 	})
 
+
+
 	router.Methods("GET").Path("/traces").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		respondWith(w, http.StatusOK, t.store.Traces())
 	})

experimental/tracer/ptrace/thread.go

@@ -13,6 +13,7 @@ const (
 	READ          = 0
 	WRITE         = 1
 	CLOSE         = 3
+	STAT          = 4
 	MMAP          = 9
 	MPROTECT      = 10
 	MADVISE       = 28
@@ -96,7 +97,7 @@ func (t *thread) syscallStopped() {
 		t.handleIO(&t.callRegs, &t.resultRegs)
 
 	// we can ignore these syscalls
-	case SETROBUSTLIST, GETID, MMAP, MPROTECT, MADVISE, SOCKET, CLONE:
+	case SETROBUSTLIST, GETID, MMAP, MPROTECT, MADVISE, SOCKET, CLONE, STAT:
 		return
 
 	default:

experimental/tracer/ui/index.html

@@ -60,7 +60,7 @@
       }
 
       function updateContainers() {
-        $.get("/containers").done(function (data) {
+        $.get("/container").done(function (data) {
           data.sort(function (a, b) {
               if (a.Name > b.Name) {
                   return 1;
@@ -99,14 +99,14 @@
       $("body").on("click", "div.mainview button.start", function() {
         var id = $(this).parent().data("containerId")
         var container = containersByID[id]
-        $.post(sprintf("/pid/%d", container.State.Pid))
+        $.post(sprintf("/container/%s", container.Id))
       })
 
       $("body").on("click", "div.mainview button.stop", function() {
         var id = $(this).parent().data("containerId")
         var container = containersByID[id]
         $.ajax({
-          url: sprintf("/pid/%d", container.State.Pid),
+          url: sprintf("/container/%s", container.Id),
           type: 'DELETE',
         });
       })

probe/process/tree.go

@@ -7,6 +7,7 @@ import (
 // Tree represents all processes on the machine.
 type Tree interface {
 	GetParent(pid int) (int, error)
+	GetChildren(pid int) ([]int, error)
 }
 
 type tree struct {
@@ -32,3 +33,30 @@ func (pt *tree) GetParent(pid int) (int, error) {
 
 	return proc.PPID, nil
 }
+
+// GetChildren
+func (pt *tree) GetChildren(pid int) ([]int, error) {
+	_, ok := pt.processes[pid]
+	if !ok {
+		return []int{}, fmt.Errorf("PID %d not found", pid)
+	}
+
+	var isChild func(id int) bool
+	isChild = func(id int) bool {
+		p, ok := pt.processes[id]
+		if !ok || p.PPID == 0 {
+			return false
+		} else if p.PPID == pid {
+			return true
+		}
+		return isChild(p.PPID)
+	}
+
+	children := []int{pid}
+	for id, _ := range pt.processes {
+		if isChild(id) {
+			children = append(children, id)
+		}
+	}
+	return children, nil
+}