(fix): allow input via stdin

Author: kameshsampath

cmd/add/main.go

@@ -4,8 +4,8 @@ import (
 	"bufio"
 	"context"
 	"flag"
-	"log"
 	"os"
+	"os/signal"
 
 	"github.com/kameshsampath/demo-protos/golang/todo"
 	"go.uber.org/zap"
@@ -14,51 +14,70 @@ import (
 	"google.golang.org/protobuf/encoding/protojson"
 )
 
+var log *zap.SugaredLogger
+
+func init() {
+	logger, _ := zap.NewDevelopment()
+	defer logger.Sync()
+	log = logger.Sugar()
+}
+
 func main() {
+	var scanner *bufio.Scanner
+	var stdin bool
 	var dbFile string
+	flag.BoolVar(&stdin, "stdin", false, "app -stdin")
 	flag.StringVar(&dbFile, "d", "data/todos.jsonl", "app -d ./todos.jsonl")
 	flag.Parse()
 
-	if _, err := os.Stat(dbFile); err != nil && os.IsNotExist(err) {
-		log.Fatalf("data file %s not found.", dbFile)
-	}
-
-	logger, _ := zap.NewDevelopment()
-	defer logger.Sync()
-	log := logger.Sugar()
-
 	conn, err := grpc.Dial(os.Getenv("SERVICE_ADDRESS"), grpc.WithTransportCredentials(insecure.NewCredentials()))
 
 	if err != nil {
 		log.Fatal(err)
 	}
 	defer conn.Close()
 
-	file, err := os.Open(dbFile)
-	if err != nil {
-		log.Fatal(err)
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
+	defer cancel()
+
+	if stdin {
+		log.Infoln("Enter Todo Task JSON to send, press CTRL+C to quit")
+		scanner = bufio.NewScanner(os.Stdin)
+		go scanAndSend(ctx, conn, scanner)
+		<-ctx.Done()
+	} else {
+		if _, err := os.Stat(dbFile); err != nil && os.IsNotExist(err) {
+			log.Fatalf("data file %s not found.", dbFile)
+		}
+		file, err := os.Open(dbFile)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer file.Close()
+		scanner = bufio.NewScanner(file)
+		scanAndSend(ctx, conn, scanner)
 	}
-	defer file.Close()
-	scanner := bufio.NewScanner(file)
+
+}
+
+func scanAndSend(ctx context.Context, conn *grpc.ClientConn, scanner *bufio.Scanner) {
 	for scanner.Scan() {
 		line := scanner.Text()
 		task := new(todo.Task)
 		if err := protojson.Unmarshal([]byte(line), task); err != nil {
 			log.Errorf("error processing record, %s: %s", line, err)
 			continue
 		}
+
 		client := todo.NewTodoClient(conn)
-		_, err = client.AddTodo(
-			context.Background(),
-			&todo.TodoAddRequest{Task: task},
-		)
+		_, err := client.AddTodo(ctx, &todo.TodoAddRequest{Task: task})
 		if err != nil {
-			log.Fatal(err)
+			log.Errorf("error adding record, %s: %s", line, err)
+			continue
 		}
 
 		if err := scanner.Err(); err != nil {
 			log.Fatal(err)
 		}
 	}
-
 }