Add legacy container log location support.

pkg/kubelet/kuberuntime/kuberuntime_container.go

@@ -97,6 +97,19 @@ func (m *kubeGenericRuntimeManager) startContainer(podSandboxID string, podSandb
 	}
 	m.recorder.Eventf(ref, api.EventTypeNormal, events.StartedContainer, "Started container with id %v", containerID)
 
+	// Symlink container logs to the legacy container log location for cluster logging
+	// support.
+	// TODO(random-liu): Remove this after cluster logging supports CRI container log path.
+	containerMeta := containerConfig.GetMetadata()
+	sandboxMeta := podSandboxConfig.GetMetadata()
+	legacySymlink := legacyLogSymlink(containerID, containerMeta.GetName(), sandboxMeta.GetName(),
+		sandboxMeta.GetNamespace())
+	containerLog := filepath.Join(podSandboxConfig.GetLogDirectory(), containerConfig.GetLogPath())
+	if err := m.osInterface.Symlink(containerLog, legacySymlink); err != nil {
+		glog.Errorf("Failed to create legacy symbolic link %q to container %q log %q: %v",
+			legacySymlink, containerID, containerLog, err)
+	}
+
 	// Step 4: execute the post start hook.
 	if container.Lifecycle != nil && container.Lifecycle.PostStart != nil {
 		kubeContainerID := kubecontainer.ContainerID{
@@ -112,8 +125,6 @@ func (m *kubeGenericRuntimeManager) startContainer(podSandboxID string, podSandb
 		}
 	}
 
-	// TODO(random-liu): Add legacy container log location support.
-
 	return "", nil
 }
 
@@ -696,7 +707,17 @@ func (m *kubeGenericRuntimeManager) ExecInContainer(containerID kubecontainer.Co
 // it will not write container logs anymore in that state.
 func (m *kubeGenericRuntimeManager) removeContainer(containerID string) error {
 	glog.V(4).Infof("Removing container %q", containerID)
-	// Cleanup the container log.
+	// Remove the container log.
+	if err := m.removeContainerLog(containerID); err != nil {
+		return err
+	}
+	// Remove the container.
+	return m.runtimeService.RemoveContainer(containerID)
+}
+
+// removeContainerLog removes the container log.
+func (m *kubeGenericRuntimeManager) removeContainerLog(containerID string) error {
+	// Remove the container log.
 	status, err := m.runtimeService.ContainerStatus(containerID)
 	if err != nil {
 		glog.Errorf("ContainerStatus for %q error: %v", containerID, err)
@@ -710,8 +731,17 @@ func (m *kubeGenericRuntimeManager) removeContainer(containerID string) error {
 		glog.Errorf("Failed to remove container %q log %q: %v", containerID, path, err)
 		return err
 	}
-	// Remove the container.
-	return m.runtimeService.RemoveContainer(containerID)
+
+	// Remove the legacy container log symlink.
+	// TODO(random-liu): Remove this after cluster logging supports CRI container log path.
+	legacySymlink := legacyLogSymlink(containerID, labeledInfo.ContainerName, labeledInfo.PodName,
+		labeledInfo.PodNamespace)
+	if err := m.osInterface.Remove(legacySymlink); err != nil && !os.IsNotExist(err) {
+		glog.Errorf("Failed to remove container %q log legacy symbolic link %q: %v",
+			containerID, legacySymlink, err)
+		return err
+	}
+	return nil
 }
 
 // DeleteContainer removes a container.

pkg/kubelet/kuberuntime/kuberuntime_container_test.go

@@ -57,7 +57,8 @@ func TestRemoveContainer(t *testing.T) {
 	assert.NoError(t, err)
 	// Verify container log is removed
 	expectedContainerLogPath := filepath.Join(podLogsRootDirectory, "12345678", "foo_0.log")
-	assert.Equal(t, fakeOS.Removes, []string{expectedContainerLogPath})
+	expectedContainerLogSymlink := legacyLogSymlink(containerId, "foo", "bar", "new")
+	assert.Equal(t, fakeOS.Removes, []string{expectedContainerLogPath, expectedContainerLogSymlink})
 	// Verify container is removed
 	fakeRuntime.AssertCalls([]string{"RemoveContainer"})
 	containers, err := fakeRuntime.ListContainers(&runtimeApi.ContainerFilter{Id: &containerId})

pkg/kubelet/kuberuntime/kuberuntime_gc.go

@@ -18,6 +18,7 @@ package kuberuntime
 
 import (
 	"fmt"
+	"os"
 	"path/filepath"
 	"sort"
 	"time"
@@ -251,6 +252,18 @@ func (cgc *containerGC) evictPodLogsDirectories(allSourcesReady bool) error {
 			}
 		}
 	}
+
+	// Remove dead container log symlinks.
+	// TODO(random-liu): Remove this after cluster logging supports CRI container log path.
+	logSymlinks, _ := filepath.Glob(filepath.Join(legacyContainerLogsDir, fmt.Sprintf("*.%s", legacyLogSuffix)))
+	for _, logSymlink := range logSymlinks {
+		if _, err := osInterface.Stat(logSymlink); os.IsNotExist(err) {
+			err := osInterface.Remove(logSymlink)
+			if err != nil {
+				glog.Errorf("Failed to remove container log dead symlink %q: %v", logSymlink, err)
+			}
+		}
+	}
 	return nil
 }
 

pkg/kubelet/kuberuntime/legacy.go

@@ -0,0 +1,41 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package kuberuntime
+
+import (
+	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
+	"k8s.io/kubernetes/pkg/kubelet/dockertools"
+)
+
+// This file implements the functions that are needed for backward
+// compatibility. Therefore, it imports various kubernetes packages
+// directly.
+
+const (
+	// legacyContainerLogsDir is the legacy location of container logs. It is the same with
+	// kubelet.containerLogsDir.
+	legacyContainerLogsDir = "/var/log/containers"
+	// legacyLogSuffix is the legacy log suffix.
+	legacyLogSuffix = dockertools.LogSuffix
+)
+
+// legacyLogSymlink composes the legacy container log path. It is only used for legacy cluster
+// logging support.
+func legacyLogSymlink(containerID string, containerName, podName, podNamespace string) string {
+	return dockertools.LogSymlink(legacyContainerLogsDir, kubecontainer.BuildPodFullName(podName, podNamespace),
+		containerName, containerID)
+}