add field selector enabled fake client

pkg/client/fake/field_selector_client.go

@@ -0,0 +1,106 @@
+/*
+Copyright 2020 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 fake
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	"sigs.k8s.io/controller-runtime/pkg/client/apiutil"
+)
+
+var _ client.Client = &fieldSelectorEnableClient{}
+
+// NewFieldSelectorEnableClient wrapper a fake client that List method enables field selector
+func NewFieldSelectorEnableClient(client client.Client, scheme *runtime.Scheme, obj runtime.Object, field string, indexerFunc client.IndexerFunc) (client.Client, error) {
+	gvk, err := apiutil.GVKForObject(obj, scheme)
+	if err != nil {
+		return nil, err
+	}
+
+	return &fieldSelectorEnableClient{
+		Client:     client,
+		scheme:     scheme,
+		gvk:        gvk,
+		fieldName:  field,
+		fieldValue: indexerFunc,
+	}, nil
+}
+
+type fieldSelectorEnableClient struct {
+	client.Client
+	scheme *runtime.Scheme
+
+	gvk schema.GroupVersionKind
+
+	fieldName  string
+	fieldValue client.IndexerFunc
+}
+
+func (f *fieldSelectorEnableClient) List(ctx context.Context, list runtime.Object, opts ...client.ListOption) error {
+	if err := f.Client.List(ctx, list, opts...); err != nil {
+		return err
+	}
+
+	if len(opts) == 0 {
+		return nil
+	}
+
+	objs, err := meta.ExtractList(list)
+	if err != nil {
+		return err
+	}
+
+	if len(objs) == 0 {
+		return nil
+	}
+
+	if gvk, err := apiutil.GVKForObject(objs[0], f.scheme); err != nil {
+		return err
+	} else if gvk != f.gvk {
+		return nil
+	}
+
+	options := client.ListOptions{}
+	options.ApplyOptions(opts)
+
+	if options.FieldSelector == nil {
+		return nil
+	}
+
+	value, ok := options.FieldSelector.RequiresExactMatch(f.fieldName)
+	if !ok {
+		return meta.SetList(list, []runtime.Object{})
+	}
+
+	filtered := make([]runtime.Object, 0)
+	for i := range objs {
+		values := f.fieldValue(objs[i])
+		if len(values) != 1 {
+			continue
+		}
+		if values[0] == value {
+			filtered = append(filtered, objs[i])
+		}
+	}
+
+	return meta.SetList(list, filtered)
+}

pkg/client/fake/field_selector_client_test.go

@@ -0,0 +1,116 @@
+/*
+Copyright 2020 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 fake
+
+import (
+	"context"
+	"testing"
+
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/kubernetes/scheme"
+
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+func TestListByFieldSelector(t *testing.T) {
+	fakeClient := NewFakeClientWithScheme(scheme.Scheme, &corev1.Pod{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "foo",
+			Namespace: "bar",
+		},
+		Spec: corev1.PodSpec{
+			NodeName: "node1",
+		},
+	})
+
+	fieldSelectorClient, err := NewFieldSelectorEnableClient(fakeClient, scheme.Scheme, &corev1.Pod{}, "spec.nodeName", func(o runtime.Object) []string {
+		po, ok := o.(*corev1.Pod)
+		if !ok {
+			return nil
+		}
+
+		return []string{po.Spec.NodeName}
+	})
+	if err != nil {
+		t.Fatalf("unexpect init client err: %v", err)
+	}
+
+	cases := []struct {
+		name      string
+		opts      client.ListOption
+		expectGot bool
+	}{
+		{
+			name:      "nil fieldSelector",
+			opts:      nil,
+			expectGot: true,
+		},
+		{
+			name: "does not match fieldSelector name",
+			opts: client.MatchingFields(fields.Set{
+				"spec.nodeName1": "node1",
+			}),
+			expectGot: false,
+		},
+		{
+			name: "does not match fieldSelector value",
+			opts: client.MatchingFields(fields.Set{
+				"spec.nodeName": "node2",
+			}),
+			expectGot: false,
+		},
+		{
+			name: "match fieldSelector name and value",
+			opts: client.MatchingFields(fields.Set{
+				"spec.nodeName": "node1",
+			}),
+			expectGot: true,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			pods := &corev1.PodList{}
+
+			if tc.opts != nil {
+				if err := fieldSelectorClient.List(context.TODO(), pods, tc.opts); err != nil {
+					t.Fatalf("unexpect list err: %v", err)
+				}
+			} else {
+				if err := fieldSelectorClient.List(context.TODO(), pods); err != nil {
+					t.Fatalf("unexpect list err: %v", err)
+				}
+			}
+
+			if tc.expectGot {
+				if len(pods.Items) == 0 {
+					t.Fatalf("list expect get Pod, but not")
+				}
+				if pods.Items[0].Name != "foo" {
+					t.Fatalf("list expect get Pod name is foo, but name is %s", pods.Items[0].Name)
+				}
+			} else if !tc.expectGot {
+				if len(pods.Items) > 0 {
+					t.Fatalf("list expect get nothing, but got %d objects", len(pods.Items))
+				}
+			}
+		})
+	}
+}