Add test for ContainerStats

pkg/kubelet/dockershim/BUILD

@@ -94,6 +94,7 @@ go_test(
         "docker_image_test.go",
         "docker_sandbox_test.go",
         "docker_service_test.go",
+        "docker_stats_test.go",
         "helpers_linux_test.go",
         "helpers_test.go",
         "naming_test.go",

pkg/kubelet/dockershim/docker_stats_test.go

@@ -0,0 +1,66 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+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 dockershim
+
+import (
+	"testing"
+
+	dockertypes "github.com/docker/docker/api/types"
+	"github.com/stretchr/testify/assert"
+	runtimeapi "k8s.io/cri-api/pkg/apis/runtime/v1alpha2"
+	"k8s.io/kubernetes/pkg/kubelet/dockershim/libdocker"
+)
+
+func TestContainerStats(t *testing.T) {
+	tests := map[string]struct {
+		containerID    string
+		container      *libdocker.FakeContainer
+		containerStats *dockertypes.StatsJSON
+		calledDetails  []libdocker.CalledDetail
+	}{
+		"container exists": {
+			"fake_container",
+			&libdocker.FakeContainer{ID: "fake_container"},
+			&dockertypes.StatsJSON{},
+			[]libdocker.CalledDetail{
+				libdocker.NewCalledDetail("get_container_stats", nil),
+				libdocker.NewCalledDetail("inspect_container_withsize", nil),
+				libdocker.NewCalledDetail("inspect_container", nil),
+				libdocker.NewCalledDetail("inspect_image", nil),
+			},
+		},
+		"container doesn't exists": {
+			"nonexistant_fake_container",
+			&libdocker.FakeContainer{ID: "fake_container"},
+			&dockertypes.StatsJSON{},
+			[]libdocker.CalledDetail{
+				libdocker.NewCalledDetail("get_container_stats", nil),
+			},
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			ds, fakeDocker, _ := newTestDockerService()
+			fakeDocker.SetFakeContainers([]*libdocker.FakeContainer{test.container})
+			fakeDocker.InjectContainerStats(map[string]*dockertypes.StatsJSON{test.container.ID: test.containerStats})
+			ds.ContainerStats(getTestCTX(), &runtimeapi.ContainerStatsRequest{ContainerId: test.containerID})
+			err := fakeDocker.AssertCallDetails(test.calledDetails...)
+			assert.NoError(t, err)
+		})
+	}
+}