Code change:
<del> /* Copyright 2023 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 plugin import ( "context" "fmt" "net" "os" "path/filepath" "sync" "testing" "github.com/stretchr/testify/assert" "google.golang.org/grpc" drapb "k8s.io/kubelet/pkg/apis/dra/v1alpha4" "k8s.io/kubernetes/test/utils/ktesting" ) const ( v1alpha4Version = "v1alpha4" ) type fakeV1alpha4GRPCServer struct { drapb.UnimplementedNodeServer } var _ drapb.NodeServer = &fakeV1alpha4GRPCServer{} func (f *fakeV1alpha4GRPCServer) NodePrepareResources(ctx context.Context, in *drapb.NodePrepareResourcesRequest) (*drapb.NodePrepareResourcesResponse, error) { return &drapb.NodePrepareResourcesResponse{Claims: map[string]*drapb.NodePrepareResourceResponse{"claim-uid": { Devices: []*drapb.Device{ { RequestNames: []string{"test-request"}, CDIDeviceIDs: []string{"test-cdi-id"}, }, }, }}}, nil } func (f *fakeV1alpha4GRPCServer) NodeUnprepareResources(ctx context.Context, in *drapb.NodeUnprepareResourcesRequest) (*drapb.NodeUnprepareResourcesResponse, error) { return &drapb.NodeUnprepareResourcesResponse{}, nil } type tearDown func() func setupFakeGRPCServer(version string) (string, tearDown, error) { p, err := os.MkdirTemp("", "dra_plugin") if err != nil { return "", nil, err } closeCh := make(chan struct{}) addr := filepath.Join(p, "server.sock") teardown := func() { close(closeCh) os.RemoveAll(addr) } listener, err := net.Listen("unix", addr) if err != nil { teardown() return "", nil, err } s := grpc.NewServer() switch version { case v1alpha4Version: fakeGRPCServer := &fakeV1alpha4GRPCServer{} drapb.RegisterNodeServer(s, fakeGRPCServer) default: return "", nil, fmt.Errorf("unsupported version: %s", version) } go func() { go s.Serve(listener) <-closeCh s.GracefulStop() }() return addr, teardown, nil } func TestGRPCConnIsReused(t *testing.T) { tCtx := ktesting.Init(t) addr, teardown, err := setupFakeGRPCServer(v1alpha4Version) if err != nil { t.Fatal(err) } defer teardown() reusedConns := make(map[*grpc.ClientConn]int) wg := sync.WaitGroup{} m := sync.Mutex{} p := &Plugin{ backgroundCtx:     tCtx, endpoint:          addr, clientCallTimeout: defaultClientCallTimeout, } conn, err := p.getOrCreateGRPCConn() defer func() { err := conn.Close() if err != nil { t.Error(err) } }() if err != nil { t.Fatal(err) } // ensure the plugin we are using is registered draPlugins.add("dummy-plugin", p) defer draPlugins.delete("dummy-plugin") // we call `NodePrepareResource` 2 times and check whether a new connection is created or the same is reused for i := 0; i < 2; i++ { wg.Add(1) go func() { defer wg.Done() client, err := NewDRAPluginClient("dummy-plugin") if err != nil { t.Error(err) return } req := &drapb.NodePrepareResourcesRequest{ Claims: []*drapb.Claim{ { Namespace: "dummy-namespace", UID:       "dummy-uid", Name:      "dummy-claim", }, }, } _, err = client.NodePrepareResources(tCtx, req) assert.NoError(t, err) client.mutex.Lock() conn := client.conn client.mutex.Unlock() m.Lock() defer m.Unlock() reusedConns[conn]++ }() } wg.Wait() // We should have only one entry otherwise it means another gRPC connection has been created if len(reusedConns) != 1 { t.Errorf("expected length to be 1 but got %d", len(reusedConns)) } if counter, ok := reusedConns[conn]; ok && counter != 2 { t.Errorf("expected counter to be 2 but got %d", counter) } } func TestNewDRAPluginClient(t *testing.T) { for _, test := range []struct { description string setup       func(string) tearDown pluginName  string shouldError bool }{ { description: "plugin name is empty", setup: func(_ string) tearDown { return func() {} }, pluginName:  "", shouldError: true, }, { description: "plugin name not found in the list", setup: func(_ string) tearDown { return func() {} }, pluginName:  "plugin-name-not-found-in-the-list", shouldError: true, }, { description: "plugin exists", setup: func(name string) tearDown { draPlugins.add(name, &Plugin{}) return func() { draPlugins.delete(name) } }, pluginName: "dummy-plugin", }, } { t.Run(test.description, func(t *testing.T) { teardown := test.setup(test.pluginName) defer teardown() client, err := NewDRAPluginClient(test.pluginName) if test.shouldError { assert.Nil(t, client) assert.Error(t, err) } else { assert.NotNil(t, client) assert.Nil(t, err) } }) } } func TestNodeUnprepareResources(t *testing.T) { for _, test := range []struct { description   string serverSetup   func(string) (string, tearDown, error) serverVersion string request       *drapb.NodeUnprepareResourcesRequest }{ { description:   "server supports v1alpha4", serverSetup:   setupFakeGRPCServer, serverVersion: v1alpha4Version, request:       &drapb.NodeUnprepareResourcesRequest{}, }, } { t.Run(test.description, func(t *testing.T) { tCtx := ktesting.Init(t) addr, teardown, err := setupFakeGRPCServer(test.serverVersion) if err != nil { t.Fatal(err) } defer teardown() p := &Plugin{ backgroundCtx:     tCtx, endpoint:          addr, clientCallTimeout: defaultClientCallTimeout, } conn, err := p.getOrCreateGRPCConn() defer func() { err := conn.Close() if err != nil { t.Error(err) } }() if err != nil { t.Fatal(err) } draPlugins.add("dummy-plugin", p) defer draPlugins.delete("dummy-plugin") client, err := NewDRAPluginClient("dummy-plugin") if err != nil { t.Fatal(err) } _, err = client.NodeUnprepareResources(tCtx, test.request) if err != nil { t.Fatal(err) } }) } } </del>

Related discussion:
text: The PR above moved everything related to into because that was where most of the code already was, but didn't renamed the files to avoid a larger diff and merge conflicts. Once is merged, we can do the renaming. Code clarity. /sig node
/triage accepted /priority important-soon
/assign
a PR can be created for this now.
will do