feat(cmd/client): implement example grpc client

Author: mateusmlo

cmd/client/client.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	pb "github.com/mateusmlo/taskqueue/proto"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+)
+
+func main() {
+	ctx := context.Background()
+	tc, err := credentials.NewClientTLSFromFile("cert/server.crt", "localhost")
+	if err != nil {
+		fmt.Printf("Failed to load TLS credentials: %s\n", err.Error())
+		panic(err)
+	}
+
+	clientConn, err := grpc.NewClient("localhost:50051", grpc.WithTransportCredentials(tc))
+	if err != nil {
+		fmt.Printf("Failed to connect to server: %s\n", err.Error())
+		panic(err)
+	}
+	defer clientConn.Close()
+
+	taskClient := pb.NewTaskQueueClient(clientConn)
+
+	res, err := taskClient.SubmitTask(ctx, &pb.SubmitTaskRequest{
+		Type:       "reverseStr",
+		Payload:    []byte("hello world"),
+		Priority:   int32(pb.Priority_HIGH),
+		MaxRetries: 3,
+	})
+
+	if err != nil {
+		log.Fatalf("Task failed to submit: %s\n", err.Error())
+	}
+
+	taskID := res.TaskId
+
+	ctxDeadline, cancelFunc := context.WithTimeout(ctx, 10*time.Second)
+
+	for {
+		fmt.Print("Polling task status...\n")
+
+		taskStatusRes, err := taskClient.GetTaskStatus(ctxDeadline, &pb.GetTaskStatusRequest{
+			TaskId: taskID,
+		})
+
+		if err != nil {
+			log.Fatalf("Failed to get task status: %s\n", err.Error())
+		}
+
+		if taskStatusRes.Status == pb.TaskStatus_COMPLETED {
+			log.Print("Task completed, fetching result...\n")
+			cancelFunc()
+			break
+		}
+
+		time.Sleep(1 * time.Second)
+	}
+
+	taskRes, err := taskClient.GetTaskResult(ctx, &pb.GetTaskResultRequest{TaskId: taskID})
+	if err != nil {
+		log.Fatalf("Failed to get task result: %s\n", err.Error())
+		panic(err)
+	}
+
+	fmt.Printf("Task result: %s\n", taskRes.GetResult())
+}