Refactoring cAdvisor interface into a package.

This will make it easier to start running the real cAdvisor alongside
Kubelet. This change is primarily no-op refactoring. The main behavioral
change is that we always create a cAdvisor interface and expect it to
always be available. When we make a request, if cAdvisor is not
connected the request fails with a connection error. This failure is
handled today as well.

pkg/kubelet/cadvisor/cadvisor.go

@@ -0,0 +1,31 @@
+/*
+Copyright 2015 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 cadvisor
+
+import (
+	"github.com/google/cadvisor/client"
+)
+
+type cadvisorClient struct {
+	*client.Client
+}
+
+func New(cc *client.Client) (Interface, error) {
+	return &cadvisorClient{
+		Client: cc,
+	}, nil
+}

pkg/kubelet/cadvisor/cadvisor_mock.go

@@ -0,0 +1,44 @@
+/*
+Copyright 2015 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 cadvisor
+
+import (
+	cadvisorApi "github.com/google/cadvisor/info/v1"
+	"github.com/stretchr/testify/mock"
+)
+
+type Mock struct {
+	mock.Mock
+}
+
+// ContainerInfo is a mock implementation of CadvisorInterface.ContainerInfo.
+func (c *Mock) ContainerInfo(name string, req *cadvisorApi.ContainerInfoRequest) (*cadvisorApi.ContainerInfo, error) {
+	args := c.Called(name, req)
+	return args.Get(0).(*cadvisorApi.ContainerInfo), args.Error(1)
+}
+
+// DockerContainer is a mock implementation of CadvisorInterface.DockerContainer.
+func (c *Mock) DockerContainer(name string, req *cadvisorApi.ContainerInfoRequest) (cadvisorApi.ContainerInfo, error) {
+	args := c.Called(name, req)
+	return args.Get(0).(cadvisorApi.ContainerInfo), args.Error(1)
+}
+
+// MachineInfo is a mock implementation of CadvisorInterface.MachineInfo.
+func (c *Mock) MachineInfo() (*cadvisorApi.MachineInfo, error) {
+	args := c.Called()
+	return args.Get(0).(*cadvisorApi.MachineInfo), args.Error(1)
+}

pkg/kubelet/cadvisor/doc.go

@@ -0,0 +1,18 @@
+/*
+Copyright 2015 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.
+*/
+
+// Kubelet interactions with cAdvisor.
+package cadvisor

pkg/kubelet/cadvisor/types.go

@@ -0,0 +1,28 @@
+/*
+Copyright 2015 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 cadvisor
+
+import (
+	cadvisorApi "github.com/google/cadvisor/info/v1"
+)
+
+// Interface is an abstract interface for testability.  It abstracts the interface to cAdvisor.
+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)
+}