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| 1 | +// ------------------------------------------------------------ |
| 2 | +// Copyright (c) Microsoft Corporation. |
| 3 | +// Licensed under the MIT License. |
| 4 | +// ------------------------------------------------------------ |
| 5 | + |
| 6 | +package main |
| 7 | + |
| 8 | +import ( |
| 9 | + "context" |
| 10 | + "encoding/json" |
| 11 | + "fmt" |
| 12 | + "log" |
| 13 | + "net" |
| 14 | + "sync" |
| 15 | + |
| 16 | + "github.com/golang/protobuf/ptypes/any" |
| 17 | + "github.com/golang/protobuf/ptypes/empty" |
| 18 | + |
| 19 | + commonv1pb "github.com/dapr/dapr/pkg/proto/common/v1" |
| 20 | + pb "github.com/dapr/dapr/pkg/proto/runtime/v1" |
| 21 | + |
| 22 | + "google.golang.org/grpc" |
| 23 | +) |
| 24 | + |
| 25 | +const ( |
| 26 | + appPort = "3000" |
| 27 | +) |
| 28 | + |
| 29 | +// server is our user app |
| 30 | +type server struct { |
| 31 | +} |
| 32 | + |
| 33 | +type messageBuffer struct { |
| 34 | + lock *sync.RWMutex |
| 35 | + successMessages []string |
| 36 | + // errorOnce is used to make sure that message is failed only once. |
| 37 | + errorOnce bool |
| 38 | + failedMessage string |
| 39 | +} |
| 40 | + |
| 41 | +func (m *messageBuffer) add(message string) { |
| 42 | + m.lock.Lock() |
| 43 | + defer m.lock.Unlock() |
| 44 | + m.successMessages = append(m.successMessages, message) |
| 45 | +} |
| 46 | + |
| 47 | +func (m *messageBuffer) getAllSuccessful() []string { |
| 48 | + m.lock.RLock() |
| 49 | + defer m.lock.RUnlock() |
| 50 | + return m.successMessages |
| 51 | +} |
| 52 | + |
| 53 | +func (m *messageBuffer) getFailed() string { |
| 54 | + m.lock.RLock() |
| 55 | + defer m.lock.RUnlock() |
| 56 | + return m.failedMessage |
| 57 | +} |
| 58 | + |
| 59 | +func (m *messageBuffer) fail(failedMessage string) bool { |
| 60 | + m.lock.Lock() |
| 61 | + defer m.lock.Unlock() |
| 62 | + // fail only for the first time. return false all other times. |
| 63 | + if !m.errorOnce { |
| 64 | + m.failedMessage = failedMessage |
| 65 | + m.errorOnce = true |
| 66 | + return m.errorOnce |
| 67 | + } |
| 68 | + return false |
| 69 | +} |
| 70 | + |
| 71 | +var messages messageBuffer = messageBuffer{ |
| 72 | + lock: &sync.RWMutex{}, |
| 73 | + successMessages: []string{}, |
| 74 | +} |
| 75 | + |
| 76 | +type receivedMessagesResponse struct { |
| 77 | + ReceivedMessages []string `json:"received_messages,omitempty"` |
| 78 | + Message string `json:"message,omitempty"` |
| 79 | + FailedMessage string `json:"failed_message,omitempty"` |
| 80 | +} |
| 81 | + |
| 82 | +func main() { |
| 83 | + log.Printf("Initializing grpc") |
| 84 | + |
| 85 | + /* #nosec */ |
| 86 | + lis, err := net.Listen("tcp", fmt.Sprintf(":%s", appPort)) |
| 87 | + if err != nil { |
| 88 | + log.Fatalf("failed to listen: %v", err) |
| 89 | + } |
| 90 | + |
| 91 | + /* #nosec */ |
| 92 | + s := grpc.NewServer() |
| 93 | + pb.RegisterAppCallbackServer(s, &server{}) |
| 94 | + |
| 95 | + log.Println("Client starting...") |
| 96 | + |
| 97 | + if err := s.Serve(lis); err != nil { |
| 98 | + log.Fatalf("failed to serve: %v", err) |
| 99 | + } |
| 100 | +} |
| 101 | + |
| 102 | +func (s *server) OnInvoke(ctx context.Context, in *commonv1pb.InvokeRequest) (*commonv1pb.InvokeResponse, error) { |
| 103 | + fmt.Printf("Got invoked method %s and data: %s\n", in.Method, string(in.GetData().Value)) |
| 104 | + |
| 105 | + switch in.Method { |
| 106 | + case "GetReceivedTopics": |
| 107 | + return s.GetReceivedTopics(ctx, in) |
| 108 | + } |
| 109 | + |
| 110 | + return &commonv1pb.InvokeResponse{}, nil |
| 111 | +} |
| 112 | + |
| 113 | +func (s *server) GetReceivedTopics(ctx context.Context, in *commonv1pb.InvokeRequest) (*commonv1pb.InvokeResponse, error) { |
| 114 | + failedMessage := messages.getFailed() |
| 115 | + log.Printf("failed message %s", failedMessage) |
| 116 | + resp := receivedMessagesResponse{ |
| 117 | + ReceivedMessages: messages.getAllSuccessful(), |
| 118 | + FailedMessage: failedMessage, |
| 119 | + } |
| 120 | + rawResp, err := json.Marshal(resp) |
| 121 | + if err != nil { |
| 122 | + log.Printf("Could not encode response: %s", err.Error()) |
| 123 | + return &commonv1pb.InvokeResponse{}, err |
| 124 | + } |
| 125 | + data := any.Any{ |
| 126 | + Value: rawResp, |
| 127 | + } |
| 128 | + return &commonv1pb.InvokeResponse{ |
| 129 | + Data: &data, |
| 130 | + }, nil |
| 131 | +} |
| 132 | + |
| 133 | +// Dapr will call this method to get the list of topics the app wants to subscribe to. |
| 134 | +func (s *server) ListTopicSubscriptions(ctx context.Context, in *empty.Empty) (*pb.ListTopicSubscriptionsResponse, error) { |
| 135 | + log.Println("List Topic Subscription called") |
| 136 | + return &pb.ListTopicSubscriptionsResponse{ |
| 137 | + Subscriptions: []*pb.TopicSubscription{}, |
| 138 | + }, nil |
| 139 | +} |
| 140 | + |
| 141 | +// This method is fired whenever a message has been published to a topic that has been subscribed. Dapr sends published messages in a CloudEvents 1.0 envelope. |
| 142 | +func (s *server) OnTopicEvent(ctx context.Context, in *pb.TopicEventRequest) (*pb.TopicEventResponse, error) { |
| 143 | + log.Printf("Message arrived - Topic: %s, Message: %s\n", in.Topic, string(in.Data)) |
| 144 | + |
| 145 | + var message string |
| 146 | + err := json.Unmarshal(in.Data, &message) |
| 147 | + log.Printf("Got message: %s", message) |
| 148 | + if err != nil { |
| 149 | + log.Printf("error parsing test-topic input binding payload: %s", err) |
| 150 | + return &pb.TopicEventResponse{}, nil |
| 151 | + } |
| 152 | + if fail := messages.fail(message); fail { |
| 153 | + // simulate failure. fail only for the first time. |
| 154 | + log.Print("failing message") |
| 155 | + return &pb.TopicEventResponse{}, nil |
| 156 | + } |
| 157 | + messages.add(message) |
| 158 | + |
| 159 | + return &pb.TopicEventResponse{ |
| 160 | + Status: pb.TopicEventResponse_SUCCESS, |
| 161 | + }, nil |
| 162 | +} |
| 163 | + |
| 164 | +func (s *server) ListInputBindings(ctx context.Context, in *empty.Empty) (*pb.ListInputBindingsResponse, error) { |
| 165 | + log.Println("List Input Bindings called") |
| 166 | + return &pb.ListInputBindingsResponse{ |
| 167 | + Bindings: []string{ |
| 168 | + "test-topic-grpc", |
| 169 | + }, |
| 170 | + }, nil |
| 171 | +} |
| 172 | + |
| 173 | +// This method gets invoked every time a new event is fired from a registered binding. The message carries the binding name, a payload and optional metadata |
| 174 | +func (s *server) OnBindingEvent(ctx context.Context, in *pb.BindingEventRequest) (*pb.BindingEventResponse, error) { |
| 175 | + fmt.Printf("Invoked from binding: %s - %s\n", in.Name, string(in.Data)) |
| 176 | + return &pb.BindingEventResponse{}, nil |
| 177 | +} |
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