Eliminate possible infinite loop in exec

If a user starts an exec session with a shell and leaves it idle long enough, they will eventually hit the Kubelet's HTTP server's read/write timeout of 5 minutes. At this time, the StartExec call to Docker exits, but if the user requested a TTY, the exec'd process does not exit. After StartExec finishes, we try to determine the exit code of the exec'd process, but in this case, we'll never get it. This change exits the loop after 5 tries if the process is still running.

Eliminate possible infinite loop in exec
7748a02e · Andy Goldstein · d763252b · 7748a02e
Commit 7748a02e authored Jun 16, 2015 by Andy Goldstein
Hide whitespace changes
Inline Side-by-side

Showing with 9 additions and 0 deletions

exec.go pkg/kubelet/dockertools/exec.go +9 -0

No files found.
--- a/pkg/kubelet/dockertools/exec.go
+++ b/pkg/kubelet/dockertools/exec.go
@@ -25,6 +25,7 @@ import (
 	kubecontainer "github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/container"
 	docker "github.com/fsouza/go-dockerclient"
+	"github.com/golang/glog"
 )
 // ExecHandler knows how to execute a command in a running Docker container.
@@ -123,6 +124,7 @@ func (*NativeExecHandler) ExecInContainer(client DockerInterface, container *doc
 		return err
 	}
 	tick := time.Tick(2 * time.Second)
+	count := 0
 	for {
 		inspect, err2 := client.InspectExec(execObj.ID)
 		if err2 != nil {
@@ -134,6 +136,13 @@ func (*NativeExecHandler) ExecInContainer(client DockerInterface, container *doc
 			}
 			break
 		}
+		count++
+		if count == 5 {
+			glog.Errorf("Exec session %s in container %s terminated but process still running!", execObj.ID, container.ID)
+			break
+		}
 		<-tick
 	}