Refactor docker-specific functions from manager to docker

container/docker/docker.go

@@ -0,0 +1,162 @@
+// Copyright 2016 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.
+
+// Provides global docker information.
+package docker
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"golang.org/x/net/context"
+
+	dockertypes "github.com/docker/engine-api/types"
+	"github.com/google/cadvisor/utils/machine"
+)
+
+func Status() (DockerStatus, error) {
+	client, err := Client()
+	if err != nil {
+		return DockerStatus{}, fmt.Errorf("unable to communicate with docker daemon: %v", err)
+	}
+	dockerInfo, err := client.Info(context.Background())
+	if err != nil {
+		return DockerStatus{}, err
+	}
+
+	out := DockerStatus{}
+	out.Version = VersionString()
+	out.KernelVersion = machine.KernelVersion()
+	out.OS = dockerInfo.OperatingSystem
+	out.Hostname = dockerInfo.Name
+	out.RootDir = dockerInfo.DockerRootDir
+	out.Driver = dockerInfo.Driver
+	out.ExecDriver = dockerInfo.ExecutionDriver
+	out.NumImages = dockerInfo.Images
+	out.NumContainers = dockerInfo.Containers
+	out.DriverStatus = make(map[string]string, len(dockerInfo.DriverStatus))
+	for _, v := range dockerInfo.DriverStatus {
+		out.DriverStatus[v[0]] = v[1]
+	}
+	return out, nil
+}
+
+func Images() ([]DockerImage, error) {
+	client, err := Client()
+	if err != nil {
+		return nil, fmt.Errorf("unable to communicate with docker daemon: %v", err)
+	}
+	images, err := client.ImageList(context.Background(), dockertypes.ImageListOptions{All: false})
+	if err != nil {
+		return nil, err
+	}
+
+	out := []DockerImage{}
+	const unknownTag = "<none>:<none>"
+	for _, image := range images {
+		if len(image.RepoTags) == 1 && image.RepoTags[0] == unknownTag {
+			// images with repo or tags are uninteresting.
+			continue
+		}
+		di := DockerImage{
+			ID:          image.ID,
+			RepoTags:    image.RepoTags,
+			Created:     image.Created,
+			VirtualSize: image.VirtualSize,
+			Size:        image.Size,
+		}
+		out = append(out, di)
+	}
+	return out, nil
+
+}
+
+// Checks whether the dockerInfo reflects a valid docker setup, and returns it if it does, or an
+// error otherwise.
+func ValidateInfo() (*dockertypes.Info, error) {
+	client, err := Client()
+	if err != nil {
+		return nil, fmt.Errorf("unable to communicate with docker daemon: %v", err)
+	}
+
+	dockerInfo, err := client.Info(context.Background())
+	if err != nil {
+		return nil, fmt.Errorf("failed to detect Docker info: %v", err)
+	}
+
+	// Fall back to version API if ServerVersion is not set in info.
+	if dockerInfo.ServerVersion == "" {
+		version, err := client.ServerVersion(context.Background())
+		if err != nil {
+			return nil, fmt.Errorf("unable to get docker version: %v", err)
+		}
+		dockerInfo.ServerVersion = version.Version
+	}
+	version, err := parseDockerVersion(dockerInfo.ServerVersion)
+	if err != nil {
+		return nil, err
+	}
+
+	if version[0] < 1 {
+		return nil, fmt.Errorf("cAdvisor requires docker version %v or above but we have found version %v reported as %q", []int{1, 0, 0}, version, dockerInfo.ServerVersion)
+	}
+
+	// Check that the libcontainer execdriver is used if the version is < 1.11
+	// (execution drivers are no longer supported as of 1.11).
+	if version[0] <= 1 && version[1] <= 10 &&
+		!strings.HasPrefix(dockerInfo.ExecutionDriver, "native") {
+		return nil, fmt.Errorf("docker found, but not using native exec driver")
+	}
+
+	if dockerInfo.Driver == "" {
+		return nil, fmt.Errorf("failed to find docker storage driver")
+	}
+
+	return &dockerInfo, nil
+}
+
+func Version() ([]int, error) {
+	return parseDockerVersion(VersionString())
+}
+
+func VersionString() string {
+	docker_version := "Unknown"
+	client, err := Client()
+	if err == nil {
+		version, err := client.ServerVersion(context.Background())
+		if err == nil {
+			docker_version = version.Version
+		}
+	}
+	return docker_version
+}
+
+// TODO: switch to a semantic versioning library.
+func parseDockerVersion(full_version_string string) ([]int, error) {
+	matches := version_re.FindAllStringSubmatch(full_version_string, -1)
+	if len(matches) != 1 {
+		return nil, fmt.Errorf("version string \"%v\" doesn't match expected regular expression: \"%v\"", full_version_string, version_regexp_string)
+	}
+	version_string_array := matches[0][1:]
+	version_array := make([]int, 3)
+	for index, version_string := range version_string_array {
+		version, err := strconv.Atoi(version_string)
+		if err != nil {
+			return nil, fmt.Errorf("error while parsing \"%v\" in \"%v\"", version_string, full_version_string)
+		}
+		version_array[index] = version
+	}
+	return version_array, nil
+}

container/docker/factory.go

@@ -19,7 +19,6 @@ import (
 	"fmt"
 	"path"
 	"regexp"
-	"strconv"
 	"strings"
 
 	"github.com/google/cadvisor/container"
@@ -164,24 +163,6 @@ var (
 	version_re            = regexp.MustCompile(version_regexp_string)
 )
 
-// TODO: switch to a semantic versioning library.
-func parseDockerVersion(full_version_string string) ([]int, error) {
-	matches := version_re.FindAllStringSubmatch(full_version_string, -1)
-	if len(matches) != 1 {
-		return nil, fmt.Errorf("version string \"%v\" doesn't match expected regular expression: \"%v\"", full_version_string, version_regexp_string)
-	}
-	version_string_array := matches[0][1:]
-	version_array := make([]int, 3)
-	for index, version_string := range version_string_array {
-		version, err := strconv.Atoi(version_string)
-		if err != nil {
-			return nil, fmt.Errorf("error while parsing \"%v\" in \"%v\"", version_string, full_version_string)
-		}
-		version_array[index] = version
-	}
-	return version_array, nil
-}
-
 // Register root container before running this function!
 func Register(factory info.MachineInfoFactory, fsInfo fs.FsInfo, ignoreMetrics container.MetricSet) error {
 	client, err := Client()

container/docker/handler.go

@@ -29,7 +29,6 @@ import (
 	info "github.com/google/cadvisor/info/v1"
 
 	docker "github.com/docker/engine-api/client"
-	dockertypes "github.com/docker/engine-api/types"
 	dockercontainer "github.com/docker/engine-api/types/container"
 	"github.com/opencontainers/runc/libcontainer/cgroups"
 	cgroupfs "github.com/opencontainers/runc/libcontainer/cgroups/fs"
@@ -349,63 +348,3 @@ func (self *dockerContainerHandler) StopWatchingSubcontainers() error {
 func (self *dockerContainerHandler) Exists() bool {
 	return common.CgroupExists(self.cgroupPaths)
 }
-
-func DockerInfo() (dockertypes.Info, error) {
-	client, err := Client()
-	if err != nil {
-		return dockertypes.Info{}, fmt.Errorf("unable to communicate with docker daemon: %v", err)
-	}
-	return client.Info(context.Background())
-}
-
-func DockerImages() ([]dockertypes.Image, error) {
-	client, err := Client()
-	if err != nil {
-		return nil, fmt.Errorf("unable to communicate with docker daemon: %v", err)
-	}
-	return client.ImageList(context.Background(), dockertypes.ImageListOptions{All: false})
-}
-
-// Checks whether the dockerInfo reflects a valid docker setup, and returns it if it does, or an
-// error otherwise.
-func ValidateInfo() (*dockertypes.Info, error) {
-	client, err := Client()
-	if err != nil {
-		return nil, fmt.Errorf("unable to communicate with docker daemon: %v", err)
-	}
-
-	dockerInfo, err := client.Info(context.Background())
-	if err != nil {
-		return nil, fmt.Errorf("failed to detect Docker info: %v", err)
-	}
-
-	// Fall back to version API if ServerVersion is not set in info.
-	if dockerInfo.ServerVersion == "" {
-		version, err := client.ServerVersion(context.Background())
-		if err != nil {
-			return nil, fmt.Errorf("unable to get docker version: %v", err)
-		}
-		dockerInfo.ServerVersion = version.Version
-	}
-	version, err := parseDockerVersion(dockerInfo.ServerVersion)
-	if err != nil {
-		return nil, err
-	}
-
-	if version[0] < 1 {
-		return nil, fmt.Errorf("cAdvisor requires docker version %v or above but we have found version %v reported as %q", []int{1, 0, 0}, version, dockerInfo.ServerVersion)
-	}
-
-	// Check that the libcontainer execdriver is used if the version is < 1.11
-	// (execution drivers are no longer supported as of 1.11).
-	if version[0] <= 1 && version[1] <= 10 &&
-		!strings.HasPrefix(dockerInfo.ExecutionDriver, "native") {
-		return nil, fmt.Errorf("docker found, but not using native exec driver")
-	}
-
-	if dockerInfo.Driver == "" {
-		return nil, fmt.Errorf("failed to find docker storage driver")
-	}
-
-	return &dockerInfo, nil
-}

container/docker/types.go

@@ -0,0 +1,37 @@
+// Copyright 2016 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.
+
+// Types used for docker containers.
+package docker
+
+type DockerStatus struct {
+	Version       string            `json:"version"`
+	KernelVersion string            `json:"kernel_version"`
+	OS            string            `json:"os"`
+	Hostname      string            `json:"hostname"`
+	RootDir       string            `json:"root_dir"`
+	Driver        string            `json:"driver"`
+	DriverStatus  map[string]string `json:"driver_status"`
+	ExecDriver    string            `json:"exec_driver"`
+	NumImages     int               `json:"num_images"`
+	NumContainers int               `json:"num_containers"`
+}
+
+type DockerImage struct {
+	ID          string   `json:"id"`
+	RepoTags    []string `json:"repo_tags"` // repository name and tags.
+	Created     int64    `json:"created"`   // unix time since creation.
+	VirtualSize int64    `json:"virtual_size"`
+	Size        int64    `json:"size"`
+}

manager/manager.go

@@ -112,10 +112,10 @@ type Manager interface {
 	CloseEventChannel(watch_id int)
 
 	// Get status information about docker.
-	DockerInfo() (DockerStatus, error)
+	DockerInfo() (docker.DockerStatus, error)
 
 	// Get details about interesting docker images.
-	DockerImages() ([]DockerImage, error)
+	DockerImages() ([]docker.DockerImage, error)
 
 	// Returns debugging information. Map of lines per category.
 	DebugInfo() map[string][]string
@@ -134,7 +134,7 @@ func New(memoryCache *memory.InMemoryCache, sysfs sysfs.SysFs, maxHousekeepingIn
 	}
 	glog.Infof("cAdvisor running in container: %q", selfContainer)
 
-	dockerInfo, err := dockerInfo()
+	dockerStatus, err := docker.Status()
 	if err != nil {
 		glog.Warningf("Unable to connect to Docker: %v", err)
 	}
@@ -146,8 +146,8 @@ func New(memoryCache *memory.InMemoryCache, sysfs sysfs.SysFs, maxHousekeepingIn
 	context := fs.Context{
 		Docker: fs.DockerContext{
 			Root:         docker.RootDir(),
-			Driver:       dockerInfo.Driver,
+			Driver:       dockerStatus.Driver,
-			DriverStatus: dockerInfo.DriverStatus,
+			DriverStatus: dockerStatus.DriverStatus,
 		},
 		RktPath: rktPath,
 	}
@@ -241,9 +241,6 @@ func (self *manager) Start() error {
 		glog.Errorf("Registration of the raw container factory failed: %v", err)
 	}
 
-	self.DockerInfo()
-	self.DockerImages()
-
 	if *enableLoadReader {
 		// Create cpu load reader.
 		cpuLoadReader, err := cpuload.New()
@@ -1127,79 +1124,12 @@ func parseEventsStoragePolicy() events.StoragePolicy {
 	return policy
 }
 
-type DockerStatus struct {
+func (m *manager) DockerImages() ([]docker.DockerImage, error) {
-	Version       string            `json:"version"`
+	return docker.Images()
-	KernelVersion string            `json:"kernel_version"`
-	OS            string            `json:"os"`
-	Hostname      string            `json:"hostname"`
-	RootDir       string            `json:"root_dir"`
-	Driver        string            `json:"driver"`
-	DriverStatus  map[string]string `json:"driver_status"`
-	ExecDriver    string            `json:"exec_driver"`
-	NumImages     int               `json:"num_images"`
-	NumContainers int               `json:"num_containers"`
 }
 
-type DockerImage struct {
+func (m *manager) DockerInfo() (docker.DockerStatus, error) {
-	ID          string   `json:"id"`
+	return docker.Status()
-	RepoTags    []string `json:"repo_tags"` // repository name and tags.
-	Created     int64    `json:"created"`   // unix time since creation.
-	VirtualSize int64    `json:"virtual_size"`
-	Size        int64    `json:"size"`
-}
-
-func (m *manager) DockerImages() ([]DockerImage, error) {
-	images, err := docker.DockerImages()
-	if err != nil {
-		return nil, err
-	}
-	out := []DockerImage{}
-	const unknownTag = "<none>:<none>"
-	for _, image := range images {
-		if len(image.RepoTags) == 1 && image.RepoTags[0] == unknownTag {
-			// images with repo or tags are uninteresting.
-			continue
-		}
-		di := DockerImage{
-			ID:          image.ID,
-			RepoTags:    image.RepoTags,
-			Created:     image.Created,
-			VirtualSize: image.VirtualSize,
-			Size:        image.Size,
-		}
-		out = append(out, di)
-	}
-	return out, nil
-}
-
-func (m *manager) DockerInfo() (DockerStatus, error) {
-	return dockerInfo()
-}
-
-func dockerInfo() (DockerStatus, error) {
-	dockerInfo, err := docker.DockerInfo()
-	if err != nil {
-		return DockerStatus{}, err
-	}
-	versionInfo, err := getVersionInfo()
-	if err != nil {
-		return DockerStatus{}, err
-	}
-	out := DockerStatus{}
-	out.Version = versionInfo.DockerVersion
-	out.KernelVersion = dockerInfo.KernelVersion
-	out.OS = dockerInfo.OperatingSystem
-	out.Hostname = dockerInfo.Name
-	out.RootDir = dockerInfo.DockerRootDir
-	out.Driver = dockerInfo.Driver
-	out.ExecDriver = dockerInfo.ExecutionDriver
-	out.NumImages = dockerInfo.Images
-	out.NumContainers = dockerInfo.Containers
-	out.DriverStatus = make(map[string]string, len(dockerInfo.DriverStatus))
-	for _, v := range dockerInfo.DriverStatus {
-		out.DriverStatus[v[0]] = v[1]
-	}
-	return out, nil
 }
 
 func (m *manager) DebugInfo() map[string][]string {
@@ -1241,7 +1171,7 @@ func getVersionInfo() (*info.VersionInfo, error) {
 
 	kernel_version := machine.KernelVersion()
 	container_os := machine.ContainerOsVersion()
-	docker_version := machine.DockerVersion()
+	docker_version := docker.VersionString()
 
 	return &info.VersionInfo{
 		KernelVersion:      kernel_version,

pages/docker.go

@@ -31,7 +31,7 @@ import (
 
 const DockerPage = "/docker/"
 
-func toStatusKV(status manager.DockerStatus) ([]keyVal, []keyVal) {
+func toStatusKV(status docker.DockerStatus) ([]keyVal, []keyVal) {
 	ds := []keyVal{
 		{Key: "Driver", Value: status.Driver},
 	}

pages/pages.go

@@ -21,6 +21,7 @@ import (
 	"net/url"
 	"strings"
 
+	"github.com/google/cadvisor/container/docker"
 	httpmux "github.com/google/cadvisor/http/mux"
 	info "github.com/google/cadvisor/info/v1"
 	"github.com/google/cadvisor/manager"
@@ -62,7 +63,7 @@ type pageData struct {
 	Root                   string
 	DockerStatus           []keyVal
 	DockerDriverStatus     []keyVal
-	DockerImages           []manager.DockerImage
+	DockerImages           []docker.DockerImage
 }
 
 func init() {

utils/machine/info.go

@@ -22,7 +22,6 @@ import (
 	"strings"
 	"syscall"
 
-	"github.com/google/cadvisor/container/docker"
 	"github.com/google/cadvisor/fs"
 	info "github.com/google/cadvisor/info/v1"
 	"github.com/google/cadvisor/utils/cloudinfo"
@@ -30,7 +29,6 @@ import (
 	"github.com/google/cadvisor/utils/sysinfo"
 
 	"github.com/golang/glog"
-	"golang.org/x/net/context"
 )
 
 var machineIdFilePath = flag.String("machine_id_file", "/etc/machine-id,/var/lib/dbus/machine-id", "Comma-separated list of files to check for machine-id. Use the first one that exists.")
@@ -136,18 +134,6 @@ func ContainerOsVersion() string {
 	return container_os
 }
 
-func DockerVersion() string {
-	docker_version := "Unknown"
-	client, err := docker.Client()
-	if err == nil {
-		version, err := client.ServerVersion(context.Background())
-		if err == nil {
-			docker_version = version.Version
-		}
-	}
-	return docker_version
-}
-
 func KernelVersion() string {
 	uname := &syscall.Utsname{}