Merge pull request #113041 from saschagrunert/kubelet-pods-creation-time

Sort kubelet pods by their creation time

pkg/kubelet/container/runtime.go

@@ -169,6 +169,8 @@ type Pod struct {
 	// The name and namespace of the pod, which is readable by human.
 	Name      string
 	Namespace string
+	// Creation timestamps of the Pod in nanoseconds.
+	CreatedAt uint64
 	// List of containers that belongs to this pod. It may contain only
 	// running containers, or mixed with dead ones (when GetPods(true)).
 	Containers []*Container

pkg/kubelet/kuberuntime/kuberuntime_manager.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"sort"
 	"time"
 
 	cadvisorapi "github.com/google/cadvisor/info/v1"
@@ -364,6 +365,7 @@ func (m *kubeGenericRuntimeManager) GetPods(all bool) ([]*kubecontainer.Pod, err
 			continue
 		}
 		p.Sandboxes = append(p.Sandboxes, converted)
+		p.CreatedAt = uint64(s.GetCreatedAt())
 	}
 
 	containers, err := m.getKubeletContainers(all)
@@ -403,6 +405,15 @@ func (m *kubeGenericRuntimeManager) GetPods(all bool) ([]*kubecontainer.Pod, err
 		result = append(result, pod)
 	}
 
+	// There are scenarios where multiple pods are running in parallel having
+	// the same name, because one of them have not been fully terminated yet.
+	// To avoid unexpected behavior on container name based search (for example
+	// by calling *Kubelet.findContainer() without specifying a pod ID), we now
+	// return the list of pods ordered by their creation time.
+	sort.SliceStable(result, func(i, j int) bool {
+		return result[i].CreatedAt > result[j].CreatedAt
+	})
+
 	return result, nil
 }
 

pkg/kubelet/kuberuntime/kuberuntime_manager_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package kuberuntime
 
 import (
+	"fmt"
 	"path/filepath"
 	"reflect"
 	"sort"
@@ -473,6 +474,7 @@ func TestGetPods(t *testing.T) {
 			ID:         types.UID("12345678"),
 			Name:       "foo",
 			Namespace:  "new",
+			CreatedAt:  uint64(fakeSandbox.CreatedAt),
 			Containers: []*kubecontainer.Container{containers[0], containers[1]},
 			Sandboxes:  []*kubecontainer.Container{sandbox},
 		},
@@ -486,6 +488,35 @@ func TestGetPods(t *testing.T) {
 	}
 }
 
+func TestGetPodsSorted(t *testing.T) {
+	fakeRuntime, _, m, err := createTestRuntimeManager()
+	assert.NoError(t, err)
+
+	pod := &v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "foo", Namespace: "bar"}}
+
+	createdTimestamps := []uint64{10, 5, 20}
+	fakeSandboxes := []*apitest.FakePodSandbox{}
+	for i, createdAt := range createdTimestamps {
+		pod.UID = types.UID(fmt.Sprint(i))
+		fakeSandboxes = append(fakeSandboxes, makeFakePodSandbox(t, m, sandboxTemplate{
+			pod:       pod,
+			createdAt: int64(createdAt),
+			state:     runtimeapi.PodSandboxState_SANDBOX_READY,
+		}))
+	}
+	fakeRuntime.SetFakeSandboxes(fakeSandboxes)
+
+	actual, err := m.GetPods(false)
+	assert.NoError(t, err)
+
+	assert.Len(t, actual, 3)
+
+	// Verify that the pods are sorted by their creation time (newest/biggest timestamp first)
+	assert.Equal(t, uint64(createdTimestamps[2]), actual[0].CreatedAt)
+	assert.Equal(t, uint64(createdTimestamps[0]), actual[1].CreatedAt)
+	assert.Equal(t, uint64(createdTimestamps[1]), actual[2].CreatedAt)
+}
+
 func TestKillPod(t *testing.T) {
 	fakeRuntime, _, m, err := createTestRuntimeManager()
 	assert.NoError(t, err)