From 51122998e3794d20ce0cb9d908a714f0d7d6f4d3 Mon Sep 17 00:00:00 2001
From: Victor Marmol <vmarmol@google.com>
Date: Thu, 12 Mar 2015 11:07:45 -0700
Subject: [PATCH] Garbage collect unidentified Kubernetes containers.

These containers may be caused by a change in the Kubernetes naming
convention. The old containers are killed, the new ones started, but the
old ones are never GC'd. This change makes Kubelet GC all Kubernetes
containers, old and new.

Fixes #5372.
---
 pkg/kubelet/kubelet.go      | 37 +++++++++++++++++++++++++++++++++++++
 pkg/kubelet/kubelet_test.go | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)

diff --git a/pkg/kubelet/kubelet.go b/pkg/kubelet/kubelet.go
index 317702c1945..a8fa6578250 100644
--- a/pkg/kubelet/kubelet.go
+++ b/pkg/kubelet/kubelet.go
@@ -466,12 +466,48 @@ func (kl *Kubelet) GarbageCollectContainers() error {
 	if err != nil {
 		return err
 	}
+
+	type unidentifiedContainer struct {
+		// Docker ID.
+		id string
+
+		// Docker container name
+		name string
+	}
+
+	unidentifiedContainers := make([]unidentifiedContainer, 0)
 	uidToIDMap := map[string][]string{}
 	for _, container := range containers {
 		_, uid, name, _ := dockertools.ParseDockerName(container.Names[0])
+		if uid == "" && name == "" {
+			unidentifiedContainers = append(unidentifiedContainers, unidentifiedContainer{
+				id:   container.ID,
+				name: container.Names[0],
+			})
+			continue
+		}
 		uidName := string(uid) + "." + name
 		uidToIDMap[uidName] = append(uidToIDMap[uidName], container.ID)
 	}
+
+	// Remove all non-running unidentified containers.
+	for _, container := range unidentifiedContainers {
+		data, err := kl.dockerClient.InspectContainer(container.id)
+		if err != nil {
+			return err
+		}
+		if data.State.Running {
+			continue
+		}
+
+		glog.Infof("Removing unidentified dead container %q with ID %q", container.name, container.id)
+		err = kl.dockerClient.RemoveContainer(docker.RemoveContainerOptions{ID: container.id})
+		if err != nil {
+			return err
+		}
+	}
+
+	// Evict dead containers according to our policies.
 	for _, list := range uidToIDMap {
 		if len(list) <= kl.maxContainerCount {
 			continue
@@ -480,6 +516,7 @@ func (kl *Kubelet) GarbageCollectContainers() error {
 			return err
 		}
 	}
+
 	return nil
 }
 
diff --git a/pkg/kubelet/kubelet_test.go b/pkg/kubelet/kubelet_test.go
index bc2b835ddb6..63dda32a03f 100644
--- a/pkg/kubelet/kubelet_test.go
+++ b/pkg/kubelet/kubelet_test.go
@@ -1741,6 +1741,43 @@ func TestKubeletGarbageCollection(t *testing.T) {
 			},
 			expectedRemoved: []string{"1706", "1876"},
 		},
+		// Remove non-running unidentified Kubernetes containers.
+		{
+			containers: []docker.APIContainers{
+				{
+					// Unidentified Kubernetes container.
+					Names: []string{"/k8s_unidentified"},
+					ID:    "1876",
+				},
+				{
+					// Unidentified (non-running) Kubernetes container.
+					Names: []string{"/k8s_unidentified"},
+					ID:    "2309",
+				},
+				{
+					// Regular Kubernetes container.
+					Names: []string{"/k8s_POD_foo_new_.deadbeef_42"},
+					ID:    "3876",
+				},
+			},
+			containerDetails: map[string]*docker.Container{
+				"1876": {
+					State: docker.State{
+						Running: false,
+					},
+					ID:      "1876",
+					Created: time.Now(),
+				},
+				"2309": {
+					State: docker.State{
+						Running: true,
+					},
+					ID:      "2309",
+					Created: time.Now(),
+				},
+			},
+			expectedRemoved: []string{"1876"},
+		},
 	}
 	for _, test := range tests {
 		kubelet, fakeDocker, _, _ := newTestKubelet(t)