From acc6b95c21fe3973d2a94a48b69df910b4765ebb Mon Sep 17 00:00:00 2001
From: Tim Hockin <thockin@google.com>
Date: Sat, 29 Nov 2014 11:02:28 -0800
Subject: [PATCH] Add functions to get kubelet directories.

Gets rid of some magic constants and makes volume plugins (coming later)
cleaner.
---
 pkg/kubelet/kubelet.go      | 38 +++++++++++++++++++++++++++++-
 pkg/kubelet/kubelet_test.go | 46 +++++++++++++++++++++++++++++++++----
 2 files changed, 79 insertions(+), 5 deletions(-)

diff --git a/pkg/kubelet/kubelet.go b/pkg/kubelet/kubelet.go
index 5407476d93b..c3f41333e84 100644
--- a/pkg/kubelet/kubelet.go
+++ b/pkg/kubelet/kubelet.go
@@ -145,6 +145,42 @@ type Kubelet struct {
 	maxContainerCount int
 }
 
+// GetRootDir returns the full path to the directory under which kubelet can
+// store data.  These functions are useful to pass interfaces to other modules
+// that may need to know where to write data without getting a whole kubelet
+// instance.
+func (kl *Kubelet) GetRootDir() string {
+	return kl.rootDirectory
+}
+
+// GetPodsDir returns the full path to the directory under which pod
+// directories are created.
+// TODO(thockin): For now, this is the same as the root because that is assumed
+// in other code.  Will fix.
+func (kl *Kubelet) GetPodsDir() string {
+	return kl.GetRootDir()
+}
+
+// GetPodDir returns the full path to the per-pod data directory for the
+// specified pod.  This directory may not exist if the pod does not exist.
+func (kl *Kubelet) GetPodDir(podUID string) string {
+	return path.Join(kl.GetRootDir(), podUID)
+}
+
+// GetPodVolumesDir returns the full path to the per-pod data directory under
+// which volumes are created for the specified pod.  This directory may not
+// exist if the pod does not exist.
+func (kl *Kubelet) GetPodVolumesDir(podUID string) string {
+	return path.Join(kl.GetPodDir(podUID), "volumes")
+}
+
+// GetPodContainerDir returns the full path to the per-pod data directory under
+// which container data is held for the specified pod.  This directory may not
+// exist if the pod or container does not exist.
+func (kl *Kubelet) GetPodContainerDir(podUID, ctrName string) string {
+	return path.Join(kl.GetPodDir(podUID), ctrName)
+}
+
 type ByCreated []*docker.Container
 
 func (a ByCreated) Len() int           { return len(a) }
@@ -477,7 +513,7 @@ func (kl *Kubelet) runContainer(pod *api.BoundPod, container *api.Container, pod
 	}
 
 	if len(container.TerminationMessagePath) != 0 {
-		p := path.Join(kl.rootDirectory, pod.Name, container.Name)
+		p := kl.GetPodContainerDir(pod.UID, container.Name)
 		if err := os.MkdirAll(p, 0750); err != nil {
 			glog.Errorf("Error on creating %s: %v", p, err)
 		} else {
diff --git a/pkg/kubelet/kubelet_test.go b/pkg/kubelet/kubelet_test.go
index 9ffc2297da6..7cb5a27381c 100644
--- a/pkg/kubelet/kubelet_test.go
+++ b/pkg/kubelet/kubelet_test.go
@@ -19,6 +19,8 @@ package kubelet
 import (
 	"fmt"
 	"net/http"
+	"os"
+	"path"
 	"reflect"
 	"regexp"
 	"strconv"
@@ -78,6 +80,40 @@ func verifyBoolean(t *testing.T, expected, value bool) {
 	}
 }
 
+func TestKubeletDirs(t *testing.T) {
+	kubelet, _, _ := newTestKubelet(t)
+	root := kubelet.rootDirectory
+	if err := os.MkdirAll(root, 0750); err != nil {
+		t.Fatalf("can't mkdir(%q): %s", root, err)
+	}
+
+	var exp, got string
+
+	got = kubelet.GetPodsDir()
+	exp = root
+	if got != exp {
+		t.Errorf("expected %q', got %q", exp, got)
+	}
+
+	got = kubelet.GetPodDir("abc123")
+	exp = path.Join(root, "abc123")
+	if got != exp {
+		t.Errorf("expected %q', got %q", exp, got)
+	}
+
+	got = kubelet.GetPodVolumesDir("abc123")
+	exp = path.Join(root, "abc123/volumes")
+	if got != exp {
+		t.Errorf("expected %q', got %q", exp, got)
+	}
+
+	got = kubelet.GetPodContainerDir("abc123", "def456")
+	exp = path.Join(root, "abc123/def456")
+	if got != exp {
+		t.Errorf("expected %q', got %q", exp, got)
+	}
+}
+
 func TestKillContainerWithError(t *testing.T) {
 	fakeDocker := &dockertools.FakeDockerClient{
 		Err: fmt.Errorf("sample error"),
@@ -196,6 +232,7 @@ func TestSyncPodsWithTerminationLog(t *testing.T) {
 	err := kubelet.SyncPods([]api.BoundPod{
 		{
 			ObjectMeta: api.ObjectMeta{
+				UID:         "0123-45-67-89ab-cdef",
 				Name:        "foo",
 				Namespace:   "new",
 				Annotations: map[string]string{ConfigSourceAnnotationKey: "test"},
@@ -216,10 +253,11 @@ func TestSyncPodsWithTerminationLog(t *testing.T) {
 
 	fakeDocker.Lock()
 	parts := strings.Split(fakeDocker.Container.HostConfig.Binds[0], ":")
-	if fakeDocker.Container.HostConfig == nil ||
-		!matchString(t, "/tmp/kubelet/foo/bar/k8s_bar\\.[a-f0-9]", parts[0]) ||
-		parts[1] != "/dev/somepath" {
-		t.Errorf("Unexpected containers created %v", fakeDocker.Container)
+	if !matchString(t, kubelet.GetPodContainerDir("0123-45-67-89ab-cdef", "bar")+"/k8s_bar\\.[a-f0-9]", parts[0]) {
+		t.Errorf("Unexpected host path: %s", parts[0])
+	}
+	if parts[1] != "/dev/somepath" {
+		t.Errorf("Unexpected container path: %s", parts[1])
 	}
 	fakeDocker.Unlock()
 }