From a0a419614f02003028da851d130c95a0f8f05ddd Mon Sep 17 00:00:00 2001
From: Rohit Jnagal <jnagal@google.com>
Date: Tue, 10 Mar 2015 23:56:09 +0000
Subject: [PATCH] Add /storage endpoint to 2.0 API.

/storage returns {device, mountpoint, capacity, usage} for all filesystems.
In addition, it also detect and applies label for each filesystem - currently two - "root", "docker-images".

/storage/<label> returns info about the filesystem with specific label. eg. /storage/root returns info for root filesystem.
---
 api/versions.go             | 19 +++++++
 container/docker/factory.go | 12 ++++-
 container/docker/handler.go |  7 +--
 container/raw/factory.go    |  9 +++-
 container/raw/handler.go    |  7 +--
 fs/fs.go                    | 98 ++++++++++++++++++++++++++++++++++++-
 fs/types.go                 |  9 ++++
 info/v2/container.go        | 17 +++++++
 manager/machine.go          |  6 +--
 manager/manager.go          | 57 +++++++++++++++++++--
 manager/manager_mock.go     |  5 ++
 11 files changed, 221 insertions(+), 25 deletions(-)

diff --git a/api/versions.go b/api/versions.go
index 1553ddf9..fe83a527 100644
--- a/api/versions.go
+++ b/api/versions.go
@@ -33,6 +33,7 @@ const (
 	summaryApi       = "summary"
 	specApi          = "spec"
 	eventsApi        = "events"
+	storageApi       = "storage"
 )
 
 // Interface for a cAdvisor API version
@@ -322,6 +323,24 @@ func (self *version2_0) HandleRequest(requestType string, request []string, m ma
 		}
 		specV2 := convertSpec(spec)
 		return writeResult(specV2, w)
+	case storageApi:
+		var err error
+		fi := []v2.FsInfo{}
+		label := r.URL.Query().Get("label")
+		if len(label) == 0 {
+			// Get all global filesystems info.
+			fi, err = m.GetFsInfo("")
+			if err != nil {
+				return err
+			}
+		} else {
+			// Get a specific label.
+			fi, err = m.GetFsInfo(label)
+			if err != nil {
+				return err
+			}
+		}
+		return writeResult(fi, w)
 	default:
 		return self.baseVersion.HandleRequest(requestType, request, m, w, r)
 	}
diff --git a/container/docker/factory.go b/container/docker/factory.go
index d7454e60..58ff4388 100644
--- a/container/docker/factory.go
+++ b/container/docker/factory.go
@@ -28,6 +28,7 @@ import (
 	"github.com/golang/glog"
 	"github.com/google/cadvisor/container"
 	"github.com/google/cadvisor/container/libcontainer"
+	"github.com/google/cadvisor/fs"
 	info "github.com/google/cadvisor/info/v1"
 	"github.com/google/cadvisor/utils"
 )
@@ -62,6 +63,10 @@ func UseSystemd() bool {
 	return useSystemd
 }
 
+func RootDir() string {
+	return *dockerRootDir
+}
+
 type dockerFactory struct {
 	machineInfoFactory info.MachineInfoFactory
 
@@ -72,6 +77,9 @@ type dockerFactory struct {
 
 	// Information about the mounted cgroup subsystems.
 	cgroupSubsystems libcontainer.CgroupSubsystems
+
+	// Information about mounted filesystems.
+	fsInfo fs.FsInfo
 }
 
 func (self *dockerFactory) String() string {
@@ -87,6 +95,7 @@ func (self *dockerFactory) NewContainerHandler(name string) (handler container.C
 		client,
 		name,
 		self.machineInfoFactory,
+		self.fsInfo,
 		*dockerRootDir,
 		self.usesAufsDriver,
 		&self.cgroupSubsystems,
@@ -151,7 +160,7 @@ func parseDockerVersion(full_version_string string) ([]int, error) {
 }
 
 // Register root container before running this function!
-func Register(factory info.MachineInfoFactory) error {
+func Register(factory info.MachineInfoFactory, fsInfo fs.FsInfo) error {
 	client, err := docker.NewClient(*ArgDockerEndpoint)
 	if err != nil {
 		return fmt.Errorf("unable to communicate with docker daemon: %v", err)
@@ -213,6 +222,7 @@ func Register(factory info.MachineInfoFactory) error {
 		client:             client,
 		usesAufsDriver:     usesAufsDriver,
 		cgroupSubsystems:   cgroupSubsystems,
+		fsInfo:             fsInfo,
 	}
 	container.RegisterContainerHandlerFactory(f)
 	return nil
diff --git a/container/docker/handler.go b/container/docker/handler.go
index a05dfe27..f0d63ac3 100644
--- a/container/docker/handler.go
+++ b/container/docker/handler.go
@@ -82,16 +82,11 @@ func newDockerContainerHandler(
 	client *docker.Client,
 	name string,
 	machineInfoFactory info.MachineInfoFactory,
+	fsInfo fs.FsInfo,
 	dockerRootDir string,
 	usesAufsDriver bool,
 	cgroupSubsystems *containerLibcontainer.CgroupSubsystems,
 ) (container.ContainerHandler, error) {
-	// TODO(vmarmol): Get from factory.
-	fsInfo, err := fs.NewFsInfo()
-	if err != nil {
-		return nil, err
-	}
-
 	// Create the cgroup paths.
 	cgroupPaths := make(map[string]string, len(cgroupSubsystems.MountPoints))
 	for key, val := range cgroupSubsystems.MountPoints {
diff --git a/container/raw/factory.go b/container/raw/factory.go
index 4cd918f3..111e422f 100644
--- a/container/raw/factory.go
+++ b/container/raw/factory.go
@@ -20,6 +20,7 @@ import (
 	"github.com/golang/glog"
 	"github.com/google/cadvisor/container"
 	"github.com/google/cadvisor/container/libcontainer"
+	"github.com/google/cadvisor/fs"
 	info "github.com/google/cadvisor/info/v1"
 )
 
@@ -29,6 +30,9 @@ type rawFactory struct {
 
 	// Information about the cgroup subsystems.
 	cgroupSubsystems *libcontainer.CgroupSubsystems
+
+	// Information about mounted filesystems.
+	fsInfo fs.FsInfo
 }
 
 func (self *rawFactory) String() string {
@@ -36,7 +40,7 @@ func (self *rawFactory) String() string {
 }
 
 func (self *rawFactory) NewContainerHandler(name string) (container.ContainerHandler, error) {
-	return newRawContainerHandler(name, self.cgroupSubsystems, self.machineInfoFactory)
+	return newRawContainerHandler(name, self.cgroupSubsystems, self.machineInfoFactory, self.fsInfo)
 }
 
 // The raw factory can handle any container.
@@ -44,7 +48,7 @@ func (self *rawFactory) CanHandle(name string) (bool, error) {
 	return true, nil
 }
 
-func Register(machineInfoFactory info.MachineInfoFactory) error {
+func Register(machineInfoFactory info.MachineInfoFactory, fsInfo fs.FsInfo) error {
 	cgroupSubsystems, err := libcontainer.GetCgroupSubsystems()
 	if err != nil {
 		return fmt.Errorf("failed to get cgroup subsystems: %v", err)
@@ -56,6 +60,7 @@ func Register(machineInfoFactory info.MachineInfoFactory) error {
 	glog.Infof("Registering Raw factory")
 	factory := &rawFactory{
 		machineInfoFactory: machineInfoFactory,
+		fsInfo:             fsInfo,
 		cgroupSubsystems:   &cgroupSubsystems,
 	}
 	container.RegisterContainerHandlerFactory(factory)
diff --git a/container/raw/handler.go b/container/raw/handler.go
index d5781e76..c8f0c2e4 100644
--- a/container/raw/handler.go
+++ b/container/raw/handler.go
@@ -71,18 +71,13 @@ type rawContainerHandler struct {
 	externalMounts []mount
 }
 
-func newRawContainerHandler(name string, cgroupSubsystems *libcontainer.CgroupSubsystems, machineInfoFactory info.MachineInfoFactory) (container.ContainerHandler, error) {
+func newRawContainerHandler(name string, cgroupSubsystems *libcontainer.CgroupSubsystems, machineInfoFactory info.MachineInfoFactory, fsInfo fs.FsInfo) (container.ContainerHandler, error) {
 	// Create the cgroup paths.
 	cgroupPaths := make(map[string]string, len(cgroupSubsystems.MountPoints))
 	for key, val := range cgroupSubsystems.MountPoints {
 		cgroupPaths[key] = path.Join(val, name)
 	}
 
-	// TODO(vmarmol): Get from factory.
-	fsInfo, err := fs.NewFsInfo()
-	if err != nil {
-		return nil, err
-	}
 	cHints, err := getContainerHintsFromFile(*argContainerHints)
 	if err != nil {
 		return nil, err
diff --git a/fs/fs.go b/fs/fs.go
index 2869f72c..613ebbcc 100644
--- a/fs/fs.go
+++ b/fs/fs.go
@@ -29,6 +29,7 @@ import (
 	"os"
 	"os/exec"
 	"path"
+	"path/filepath"
 	"regexp"
 	"strconv"
 	"strings"
@@ -41,6 +42,11 @@ import (
 
 var partitionRegex = regexp.MustCompile("^(:?(:?s|xv)d[a-z]+\\d*|dm-\\d+)$")
 
+const (
+	LabelSystemRoot   = "root"
+	LabelDockerImages = "docker-images"
+)
+
 type partition struct {
 	mountpoint string
 	major      uint
@@ -48,15 +54,26 @@ type partition struct {
 }
 
 type RealFsInfo struct {
+	// Map from block device path to partition information.
 	partitions map[string]partition
+	// Map from label to block device path.
+	// Labels are intent-specific tags that are auto-detected.
+	labels map[string]string
 }
 
-func NewFsInfo() (FsInfo, error) {
+type Context struct {
+	// docker root directory.
+	DockerRoot string
+}
+
+func NewFsInfo(context Context) (FsInfo, error) {
 	mounts, err := mount.GetMounts()
 	if err != nil {
 		return nil, err
 	}
 	partitions := make(map[string]partition, 0)
+	fsInfo := &RealFsInfo{}
+	fsInfo.labels = make(map[string]string, 0)
 	for _, mount := range mounts {
 		if !strings.HasPrefix(mount.Fstype, "ext") && mount.Fstype != "btrfs" {
 			continue
@@ -68,7 +85,84 @@ func NewFsInfo() (FsInfo, error) {
 		partitions[mount.Source] = partition{mount.Mountpoint, uint(mount.Major), uint(mount.Minor)}
 	}
 	glog.Infof("Filesystem partitions: %+v", partitions)
-	return &RealFsInfo{partitions}, nil
+	fsInfo.partitions = partitions
+	fsInfo.addLabels(context)
+	return fsInfo, nil
+}
+
+func (self *RealFsInfo) addLabels(context Context) {
+	dockerPaths := getDockerImagePaths(context)
+	for src, p := range self.partitions {
+		if p.mountpoint == "/" {
+			if _, ok := self.labels[LabelSystemRoot]; !ok {
+				self.labels[LabelSystemRoot] = src
+			}
+		}
+		self.updateDockerImagesPath(src, p.mountpoint, dockerPaths)
+		// TODO(rjnagal): Add label for docker devicemapper pool.
+	}
+}
+
+// Generate a list of possible mount points for docker image management from the docker root directory.
+// Right now, we look for each type of supported graph driver directories, but we can do better by parsing
+// some of the context from `docker info`.
+func getDockerImagePaths(context Context) []string {
+	// TODO(rjnagal): Detect docker root and graphdriver directories from docker info.
+	dockerRoot := context.DockerRoot
+	dockerImagePaths := []string{}
+	for _, dir := range []string{"devicemapper", "btrfs", "aufs"} {
+		dockerImagePaths = append(dockerImagePaths, path.Join(dockerRoot, dir))
+	}
+	for dockerRoot != "/" && dockerRoot != "." {
+		dockerImagePaths = append(dockerImagePaths, dockerRoot)
+		dockerRoot = filepath.Dir(dockerRoot)
+	}
+	dockerImagePaths = append(dockerImagePaths, "/")
+	return dockerImagePaths
+}
+
+// This method compares the mountpoint with possible docker image mount points. If a match is found,
+// docker images label is added to the partition.
+func (self *RealFsInfo) updateDockerImagesPath(source string, mountpoint string, dockerImagePaths []string) {
+	for _, v := range dockerImagePaths {
+		if v == mountpoint {
+			if i, ok := self.labels[LabelDockerImages]; ok {
+				// pick the innermost mountpoint.
+				mnt := self.partitions[i].mountpoint
+				if len(mnt) < len(mountpoint) {
+					self.labels[LabelDockerImages] = source
+				}
+			} else {
+				self.labels[LabelDockerImages] = source
+			}
+		}
+	}
+}
+
+func (self *RealFsInfo) GetDeviceForLabel(label string) (string, error) {
+	dev, ok := self.labels[label]
+	if !ok {
+		return "", fmt.Errorf("non-existent label %q", label)
+	}
+	return dev, nil
+}
+
+func (self *RealFsInfo) GetLabelsForDevice(device string) ([]string, error) {
+	labels := []string{}
+	for label, dev := range self.labels {
+		if dev == device {
+			labels = append(labels, label)
+		}
+	}
+	return labels, nil
+}
+
+func (self *RealFsInfo) GetMountpointForDevice(dev string) (string, error) {
+	p, ok := self.partitions[dev]
+	if !ok {
+		return "", fmt.Errorf("no partition info for device %q", dev)
+	}
+	return p.mountpoint, nil
 }
 
 func (self *RealFsInfo) GetFsInfoForPath(mountSet map[string]struct{}) ([]Fs, error) {
diff --git a/fs/types.go b/fs/types.go
index 9cba902b..77a46a88 100644
--- a/fs/types.go
+++ b/fs/types.go
@@ -53,4 +53,13 @@ type FsInfo interface {
 
 	// Returns the block device info of the filesystem on which 'dir' resides.
 	GetDirFsDevice(dir string) (*DeviceInfo, error)
+
+	// Returns the device name associated with a particular label.
+	GetDeviceForLabel(label string) (string, error)
+
+	// Returns all labels associated with a particular device name.
+	GetLabelsForDevice(device string) ([]string, error)
+
+	// Returns the mountpoint associated with a particular device.
+	GetMountpointForDevice(device string) (string, error)
 }
diff --git a/info/v2/container.go b/info/v2/container.go
index 65d85c2e..33745ec6 100644
--- a/info/v2/container.go
+++ b/info/v2/container.go
@@ -97,3 +97,20 @@ type DerivedStats struct {
 	// Percentile in last day.
 	DayUsage Usage `json:"day_usage"`
 }
+
+type FsInfo struct {
+	// The block device name associated with the filesystem.
+	Device string `json:"device"`
+
+	// Path where the filesystem is mounted.
+	Mountpoint string `json:"mountpoint"`
+
+	// Filesystem usage in bytes.
+	Capacity uint64 `json:"capacity"`
+
+	// Number of bytes used on this filesystem.
+	Usage uint64 `json:"usage"`
+
+	// Labels associated with this filesystem.
+	Labels []string `json:"labels"`
+}
diff --git a/manager/machine.go b/manager/machine.go
index 8a0a6592..c424cbf6 100644
--- a/manager/machine.go
+++ b/manager/machine.go
@@ -223,7 +223,7 @@ func getMachineID() string {
 	return ""
 }
 
-func getMachineInfo(sysFs sysfs.SysFs) (*info.MachineInfo, error) {
+func getMachineInfo(sysFs sysfs.SysFs, fsInfo fs.FsInfo) (*info.MachineInfo, error) {
 	cpuinfo, err := ioutil.ReadFile("/proc/cpuinfo")
 	clockSpeed, err := getClockSpeed(cpuinfo)
 	if err != nil {
@@ -241,10 +241,6 @@ func getMachineInfo(sysFs sysfs.SysFs) (*info.MachineInfo, error) {
 		return nil, err
 	}
 
-	fsInfo, err := fs.NewFsInfo()
-	if err != nil {
-		return nil, err
-	}
 	filesystems, err := fsInfo.GetGlobalFsInfo()
 	if err != nil {
 		return nil, err
diff --git a/manager/manager.go b/manager/manager.go
index b7edeed9..b35a622e 100644
--- a/manager/manager.go
+++ b/manager/manager.go
@@ -30,6 +30,7 @@ import (
 	"github.com/google/cadvisor/container/docker"
 	"github.com/google/cadvisor/container/raw"
 	"github.com/google/cadvisor/events"
+	"github.com/google/cadvisor/fs"
 	info "github.com/google/cadvisor/info/v1"
 	"github.com/google/cadvisor/info/v2"
 	"github.com/google/cadvisor/storage/memory"
@@ -74,6 +75,10 @@ type Manager interface {
 	// Get version information about different components we depend on.
 	GetVersionInfo() (*info.VersionInfo, error)
 
+	// Get filesystem information for a given label.
+	// Returns information for all global filesystems if label is empty.
+	GetFsInfo(label string) ([]v2.FsInfo, error)
+
 	// Get events streamed through passedChannel that fit the request.
 	WatchForEvents(request *events.Request, passedChannel chan *events.Event) error
 
@@ -94,15 +99,21 @@ func New(memoryStorage *memory.InMemoryStorage, sysfs sysfs.SysFs) (Manager, err
 	}
 	glog.Infof("cAdvisor running in container: %q", selfContainer)
 
+	context := fs.Context{DockerRoot: docker.RootDir()}
+	fsInfo, err := fs.NewFsInfo(context)
+	if err != nil {
+		return nil, err
+	}
 	newManager := &manager{
 		containers:        make(map[namespacedContainerName]*containerData),
 		quitChannels:      make([]chan error, 0, 2),
 		memoryStorage:     memoryStorage,
+		fsInfo:            fsInfo,
 		cadvisorContainer: selfContainer,
 		startupTime:       time.Now(),
 	}
 
-	machineInfo, err := getMachineInfo(sysfs)
+	machineInfo, err := getMachineInfo(sysfs, fsInfo)
 	if err != nil {
 		return nil, err
 	}
@@ -119,13 +130,13 @@ func New(memoryStorage *memory.InMemoryStorage, sysfs sysfs.SysFs) (Manager, err
 	newManager.eventHandler = events.NewEventManager()
 
 	// Register Docker container factory.
-	err = docker.Register(newManager)
+	err = docker.Register(newManager, fsInfo)
 	if err != nil {
 		glog.Errorf("Docker container factory registration failed: %v.", err)
 	}
 
 	// Register the raw driver.
-	err = raw.Register(newManager)
+	err = raw.Register(newManager, fsInfo)
 	if err != nil {
 		return nil, fmt.Errorf("registration of the raw container factory failed: %v", err)
 	}
@@ -146,6 +157,7 @@ type manager struct {
 	containers             map[namespacedContainerName]*containerData
 	containersLock         sync.RWMutex
 	memoryStorage          *memory.InMemoryStorage
+	fsInfo                 fs.FsInfo
 	machineInfo            info.MachineInfo
 	versionInfo            info.VersionInfo
 	quitChannels           []chan error
@@ -439,6 +451,45 @@ func (self *manager) GetContainerDerivedStats(containerName string) (v2.DerivedS
 	return cont.DerivedStats()
 }
 
+func (self *manager) GetFsInfo(label string) ([]v2.FsInfo, error) {
+	var empty time.Time
+	// Get latest data from filesystems hanging off root container.
+	stats, err := self.memoryStorage.RecentStats("/", empty, empty, 1)
+	if err != nil {
+		return nil, err
+	}
+	dev := ""
+	if len(label) != 0 {
+		dev, err = self.fsInfo.GetDeviceForLabel(label)
+		if err != nil {
+			return nil, err
+		}
+	}
+	fsInfo := []v2.FsInfo{}
+	for _, fs := range stats[0].Filesystem {
+		if len(label) != 0 && fs.Device != dev {
+			continue
+		}
+		mountpoint, err := self.fsInfo.GetMountpointForDevice(fs.Device)
+		if err != nil {
+			return nil, err
+		}
+		labels, err := self.fsInfo.GetLabelsForDevice(fs.Device)
+		if err != nil {
+			return nil, err
+		}
+		fi := v2.FsInfo{
+			Device:     fs.Device,
+			Mountpoint: mountpoint,
+			Capacity:   fs.Limit,
+			Usage:      fs.Usage,
+			Labels:     labels,
+		}
+		fsInfo = append(fsInfo, fi)
+	}
+	return fsInfo, nil
+}
+
 func (m *manager) GetMachineInfo() (*info.MachineInfo, error) {
 	// Copy and return the MachineInfo.
 	return &m.machineInfo, nil
diff --git a/manager/manager_mock.go b/manager/manager_mock.go
index 655c4b2e..a14619e3 100644
--- a/manager/manager_mock.go
+++ b/manager/manager_mock.go
@@ -84,3 +84,8 @@ func (c *ManagerMock) GetVersionInfo() (*info.VersionInfo, error) {
 	args := c.Called()
 	return args.Get(0).(*info.VersionInfo), args.Error(1)
 }
+
+func (c *ManagerMock) GetFsInfo() ([]v2.FsInfo, error) {
+	args := c.Called()
+	return args.Get(0).([]v2.FsInfo), args.Error(1)
+}