Merge pull request #2171 from petrkotas/fix-vnc

Fix disappearing vnc socket

cmd/virt-launcher/virt-launcher.go

@@ -302,6 +302,26 @@ func waitForFinalNotify(deleteNotificationSent chan watch.Event,
 	}
 }
 
+// writeProtectPrivateDir waits until the kubevirt private vnc socket exists and than mark its folder as read only
+// this is a workaround preventing QEMU from deleting its sockets prematurely as described in a bug https://bugs.launchpad.net/qemu/+bug/1795100
+// once the QEMU 4.0 is released the need for this workaround goes away
+// Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1683964
+func writeProtectPrivateDir(uid string) {
+	vncAppeared := false
+	// waits maximum of 20s for vnc file to appear
+	for i := 0; i < 20; i++ {
+		if _, err := os.Stat(filepath.Join("/var/run/kubevirt-private", uid, "virt-vnc")); os.IsNotExist(err) {
+			time.Sleep(1 * time.Second)
+			continue
+		}
+		vncAppeared = true
+		break
+	}
+	if vncAppeared {
+		os.Chmod(filepath.Join("/var/run/kubevirt-private", uid), 0444)
+	}
+}
+
 func main() {
 	qemuTimeout := pflag.Duration("qemu-timeout", defaultStartTimeout, "Amount of time to wait for qemu")
 	virtShareDir := pflag.String("kubevirt-share-dir", "/var/run/kubevirt", "Shared directory between virt-handler and virt-launcher")
@@ -432,6 +452,12 @@ func main() {
 			*gracePeriodSeconds,
 			shutdownCallback)
 
+		// waits until virt-vnc socket is ready and than mark its parent folder as read only
+		// workaround preventing QEMU from deleting socket prematurely
+		// the code need to be executed after the QEMU reports VM is running, so the wait
+		// for socket creation is the shortest possible
+		go writeProtectPrivateDir(*uid)
+
 		// This is a wait loop that monitors the qemu pid. When the pid
 		// exits, the wait loop breaks.
 		mon.RunForever(*qemuTimeout, signalStopChan)

tests/vnc_test.go

@@ -57,7 +57,7 @@ var _ = Describe("[rfe_id:127][crit:medium][vendor:cnv-qe@redhat.com][level:comp
 
 		Context("with VNC connection", func() {
 
-			It("[test_id:1611]should allow accessing the VNC device", func() {
+			vncConnect := func() {
 				pipeInReader, _ := io.Pipe()
 				pipeOutReader, pipeOutWriter := io.Pipe()
 				defer pipeInReader.Close()
@@ -113,6 +113,17 @@ var _ = Describe("[rfe_id:127][crit:medium][vendor:cnv-qe@redhat.com][level:comp
 				By("Checking the response from VNC server")
 				Expect(response).To(Equal("RFB 003.008\n"))
 				Expect(err).To(BeNil())
+			}
+
+			It("[test_id:1611]should allow accessing the VNC device", func() {
+				vncConnect()
+			})
+
+			It("should allow accessing the VNC device multiple times", func() {
+
+				for i := 0; i < 10; i++ {
+					vncConnect()
+				}
 			})
 		})