gRPC for internal communication in Microservices - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a gRPC service method.

Microservices

service UserService {
  rpc GetUser([1]) returns (UserResponse);
}

Drag options to blanks, or click blank then click option'

AUserRequest

BUserId

CUserResponse

DUserData

Attempts:

3 left

💡 Hint

Common Mistakes

Using the response message type as input.

Using a field name instead of a message type.

The gRPC method takes a request message as input. Here, UserRequest is the correct input message type.

2fill in blank

medium

Complete the code to create a gRPC client stub in Go.

Microservices

conn, err := grpc.Dial(address, grpc.WithInsecure())
if err != nil {
  log.Fatalf("did not connect: %v", err)
}
defer conn.Close()
client := [1](conn)

Drag options to blanks, or click blank then click option'

ANewUserServiceClient

BNewGrpcClient

CNewClientStub

DNewServiceClient

Attempts:

3 left

💡 Hint

Common Mistakes

Using a generic or incorrect constructor function.

Forgetting to pass the connection object.

The client stub is created using the generated function NewUserServiceClient with the connection.

3fill in blank

hard

Fix the error in the server implementation to register the gRPC service.

Microservices

grpcServer := grpc.NewServer()
[1](grpcServer, &server{})

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ARegisterUserServer

BRegisterGrpcServer

CRegisterService

DRegisterUserServiceServer

Attempts:

3 left

💡 Hint

Common Mistakes

Using a generic or incorrect registration function name.

Omitting the service implementation pointer.

The correct function to register the service is RegisterUserServiceServer, generated by the gRPC tools.

4fill in blank

hard

Fill both blanks to define a unary gRPC method handler signature in Go.

Microservices

func (s *server) GetUser(ctx context.Context, [1] *UserRequest) (*UserResponse, [2]) {
  // implementation
}

Drag options to blanks, or click blank then click option'

Areq

Berr

Crequest

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect parameter names.

Returning a non-error type as the second return value.

The method takes a request pointer named request and returns a response pointer and an error.

5fill in blank

hard

Fill all three blanks to create a gRPC client call and handle the response in Go.

Microservices

resp, [1] := client.GetUser(context.Background(), &[2]{})
if [3] != nil {
  log.Fatalf("could not get user: %v", err)
}
// use resp

Drag options to blanks, or click blank then click option'

Aerr

BUserRequest

Drequest

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent variable names for error.

Passing incorrect request message types.

The client call returns a response and an error (err). The request message is UserRequest. The error variable is checked to handle failures.