Adding cAdvisor API to get image usage information.

pkg/kubelet/cadvisor/cadvisor_fake.go

@@ -18,6 +18,7 @@ package cadvisor
 
 import (
 	cadvisorApi "github.com/google/cadvisor/info/v1"
+	cadvisorApi2 "github.com/google/cadvisor/info/v2"
 )
 
 // Fake cAdvisor implementation.
@@ -37,3 +38,7 @@ func (c *Fake) DockerContainer(name string, req *cadvisorApi.ContainerInfoReques
 func (c *Fake) MachineInfo() (*cadvisorApi.MachineInfo, error) {
 	return new(cadvisorApi.MachineInfo), nil
 }
+
+func (c *Fake) DockerImagesFsInfo() (cadvisorApi2.FsInfo, error) {
+	return cadvisorApi2.FsInfo{}, nil
+}

pkg/kubelet/cadvisor/cadvisor_linux.go

@@ -25,8 +25,10 @@ import (
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/golang/glog"
+	cadvisorFs "github.com/google/cadvisor/fs"
 	cadvisorHttp "github.com/google/cadvisor/http"
 	cadvisorApi "github.com/google/cadvisor/info/v1"
+	cadvisorApi2 "github.com/google/cadvisor/info/v2"
 	"github.com/google/cadvisor/manager"
 	"github.com/google/cadvisor/storage/memory"
 	"github.com/google/cadvisor/utils/sysfs"
@@ -110,3 +112,19 @@ func (self *cadvisorClient) ContainerInfo(name string, req *cadvisorApi.Containe
 func (self *cadvisorClient) MachineInfo() (*cadvisorApi.MachineInfo, error) {
 	return self.GetMachineInfo()
 }
+
+func (self *cadvisorClient) DockerImagesFsInfo() (cadvisorApi2.FsInfo, error) {
+	res, err := self.GetFsInfo(cadvisorFs.LabelDockerImages)
+	if err != nil {
+		return cadvisorApi2.FsInfo{}, err
+	}
+	if len(res) == 0 {
+		return cadvisorApi2.FsInfo{}, fmt.Errorf("failed to find information for the filesystem containing Docker images")
+	}
+	// TODO(vmarmol): Handle this better when Docker has more than one image filesystem.
+	if len(res) > 1 {
+		glog.Warningf("More than one Docker images filesystem: %#v. Only using the first one", res)
+	}
+
+	return res[0], nil
+}

pkg/kubelet/cadvisor/cadvisor_mock.go

@@ -18,6 +18,7 @@ package cadvisor
 
 import (
 	cadvisorApi "github.com/google/cadvisor/info/v1"
+	cadvisorApi2 "github.com/google/cadvisor/info/v2"
 	"github.com/stretchr/testify/mock"
 )
 
@@ -44,3 +45,8 @@ func (c *Mock) MachineInfo() (*cadvisorApi.MachineInfo, error) {
 	args := c.Called()
 	return args.Get(0).(*cadvisorApi.MachineInfo), args.Error(1)
 }
+
+func (c *Mock) DockerImagesFsInfo() (cadvisorApi2.FsInfo, error) {
+	args := c.Called()
+	return args.Get(0).(cadvisorApi2.FsInfo), args.Error(1)
+}

pkg/kubelet/cadvisor/cadvisor_unsupported.go

@@ -22,6 +22,7 @@ import (
 	"errors"
 
 	cadvisorApi "github.com/google/cadvisor/info/v1"
+	cadvisorApi2 "github.com/google/cadvisor/info/v2"
 )
 
 type cadvisorUnsupported struct {
@@ -46,3 +47,7 @@ func (self *cadvisorUnsupported) ContainerInfo(name string, req *cadvisorApi.Con
 func (self *cadvisorUnsupported) MachineInfo() (*cadvisorApi.MachineInfo, error) {
 	return nil, unsupportedErr
 }
+
+func (self *cadvisorUnsupported) DockerImagesFsInfo() (cadvisorApi2.FsInfo, error) {
+	return cadvisorApi2.FsInfo{}, unsupportedErr
+}

pkg/kubelet/cadvisor/types.go

@@ -18,6 +18,7 @@ package cadvisor
 
 import (
 	cadvisorApi "github.com/google/cadvisor/info/v1"
+	cadvisorApi2 "github.com/google/cadvisor/info/v2"
 )
 
 // Interface is an abstract interface for testability.  It abstracts the interface to cAdvisor.
@@ -25,4 +26,7 @@ type Interface interface {
 	DockerContainer(name string, req *cadvisorApi.ContainerInfoRequest) (cadvisorApi.ContainerInfo, error)
 	ContainerInfo(name string, req *cadvisorApi.ContainerInfoRequest) (*cadvisorApi.ContainerInfo, error)
 	MachineInfo() (*cadvisorApi.MachineInfo, error)
+
+	// Returns usage information about the filesystem holding Docker images.
+	DockerImagesFsInfo() (cadvisorApi2.FsInfo, error)
 }