Remove SplitName().

This is possible thanks to the new libcontainer interface that allows
the use of absolute paths.

container/docker/factory.go

@@ -18,6 +18,7 @@ import (
 	"flag"
 	"fmt"
 	"log"
+	"path"
 	"regexp"
 	"strconv"
 	"strings"
@@ -25,7 +26,6 @@ import (
 	"github.com/docker/libcontainer/cgroups/systemd"
 	"github.com/fsouza/go-dockerclient"
 	"github.com/google/cadvisor/container"
-	"github.com/google/cadvisor/container/libcontainer"
 	"github.com/google/cadvisor/info"
 )
 
@@ -75,10 +75,7 @@ func (self *dockerFactory) CanHandle(name string) bool {
 		return false
 	}
 	// Check if the container is known to docker and it is active.
-	_, id, err := libcontainer.SplitName(name)
+	id := path.Base(name)
-	if err != nil {
-		return false
-	}
 	ctnr, err := self.client.InspectContainer(id)
 	// We assume that if Inspect fails then the container is not known to docker.
 	// TODO(vishh): Detect lxc containers and avoid handling them.

container/docker/handler.go

@@ -65,11 +65,8 @@ func newDockerContainerHandler(
 	if handler.isDockerRoot() {
 		return handler, nil
 	}
-	parent, id, err := containerLibcontainer.SplitName(name)
+	id := path.Base(name)
-	if err != nil {
+	handler.parent = path.Dir(name)
-		return nil, fmt.Errorf("invalid docker container %v: %v", name, err)
-	}
-	handler.parent = parent
 	handler.id = id
 	ctnr, err := client.InspectContainer(id)
 	// We assume that if Inspect fails then the container is not known to docker.

container/libcontainer/helpers.go

@@ -15,17 +15,12 @@
 package libcontainer
 
 import (
-	"bufio"
-	"path"
-	"path/filepath"
-	"strings"
 	"time"
 
 	"github.com/docker/libcontainer"
 	"github.com/docker/libcontainer/cgroups"
 	cgroupfs "github.com/docker/libcontainer/cgroups/fs"
 	"github.com/google/cadvisor/info"
-	"github.com/google/cadvisor/utils/fs"
 )
 
 // Get stats of the specified container
@@ -88,48 +83,3 @@ func toContainerStats(libcontainerStats *libcontainer.ContainerStats) *info.Cont
 
 	return ret
 }
-
-// Given a container name, returns the parent and name of the container to be fed to libcontainer.
-func SplitName(containerName string) (string, string, error) {
-	parent, id := path.Split(containerName)
-	cgroupSelf, err := fs.Open("/proc/1/cgroup")
-	if err != nil {
-		return "", "", err
-	}
-	scanner := bufio.NewScanner(cgroupSelf)
-
-	// Find how nested we are. Libcontainer takes container names relative to the current process.
-	subsys := []string{"memory", "cpu"}
-	nestedLevels := 0
-	for scanner.Scan() {
-		line := scanner.Text()
-		elems := strings.Split(line, ":")
-		if len(elems) < 3 {
-			continue
-		}
-		for _, s := range subsys {
-			if elems[1] == s {
-				if elems[2] == "/" {
-					// We're running at root, no nesting.
-					nestedLevels = 0
-				} else {
-					// Count how deeply nested we are.
-					nestedLevels = strings.Count(elems[2], "/")
-				}
-				break
-			}
-		}
-	}
-	if nestedLevels > 0 {
-		// we are running inside a docker container
-		upperLevel := strings.Repeat("../", nestedLevels)
-		parent = filepath.Join(upperLevel, parent)
-	}
-
-	// Strip the last "/"
-	if parent[len(parent)-1] == '/' {
-		parent = parent[:len(parent)-1]
-	}
-
-	return parent, id, nil
-}

container/libcontainer/helpers_test.go

@@ -1,90 +0,0 @@
-// Copyright 2014 Google Inc. All Rights Reserved.
-//
-// 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 libcontainer
-
-import (
-	"testing"
-
-	"code.google.com/p/gomock/gomock"
-
-	"github.com/google/cadvisor/utils/fs"
-	"github.com/google/cadvisor/utils/fs/mockfs"
-)
-
-var initCgroupsToParentAndID = []struct {
-	InitCgroupFileContent string
-	ContainerPath         string
-	Parent                string
-	Id                    string
-	Error                 error
-}{
-	{
-		`
-11:name=systemd:/
-10:hugetlb:/
-9:perf_event:/
-8:blkio:/
-7:freezer:/
-6:devices:/
-5:memory:/
-4:cpuacct:/
-3:cpu:/
-2:cpuset:/
-`,
-		"/",
-		"",
-		"",
-		nil,
-	},
-	{
-		`
-11:name=systemd:/
-10:hugetlb:/
-9:perf_event:/
-8:blkio:/
-7:freezer:/
-6:devices:/
-5:memory:/docker/hash
-4:cpuacct:/
-3:cpu:/docker/hash
-2:cpuset:/
-`,
-		"/parent/id",
-		"../../parent",
-		"id",
-		nil,
-	},
-}
-
-func TestSplitName(t *testing.T) {
-	mockCtrl := gomock.NewController(t)
-	defer mockCtrl.Finish()
-
-	for _, testCase := range initCgroupsToParentAndID {
-		mfs := mockfs.NewMockFileSystem(mockCtrl)
-		mockfs.AddTextFile(mfs, "/proc/1/cgroup", testCase.InitCgroupFileContent)
-		fs.ChangeFileSystem(mfs)
-		parent, id, err := SplitName(testCase.ContainerPath)
-		if testCase.Error != nil {
-			if err == nil {
-				t.Fatalf("did not receive expected error.\ncontent:%v\n, path:%v\n, expected error:%v\n", testCase.InitCgroupFileContent, testCase.ContainerPath, testCase.Error)
-			}
-			continue
-		}
-		if testCase.Parent != parent || testCase.Id != id {
-			t.Errorf("unexpected parent or id:\ncontent:%v\npath:%v\nexpected parent: %v; recevied parent: %v;\nexpected id: %v; received id: %v", testCase.InitCgroupFileContent, testCase.ContainerPath, testCase.Parent, parent, testCase.Id, id)
-		}
-	}
-}

container/raw/handler.go

@@ -38,15 +38,11 @@ type rawContainerHandler struct {
 }
 
 func newRawContainerHandler(name string, cgroupSubsystems *cgroupSubsystems, machineInfoFactory info.MachineInfoFactory) (container.ContainerHandler, error) {
-	parent, id, err := libcontainer.SplitName(name)
-	if err != nil {
-		return nil, err
-	}
 	return &rawContainerHandler{
 		name: name,
 		cgroup: &cgroups.Cgroup{
-			Parent: parent,
+			Parent: "/",
-			Name:   id,
+			Name:   name,
 		},
 		cgroupSubsystems:   cgroupSubsystems,
 		machineInfoFactory: machineInfoFactory,