From 25de51fc024f642d9ac888257b1485939a1d4a14 Mon Sep 17 00:00:00 2001
From: Can Guler <canguler@google.com>
Date: Fri, 21 Dec 2018 16:55:49 -0800
Subject: [PATCH] example: errors (#2534)

* Adds readme.

* Fills readme.

* Adds readme.

* Moves error examples.

* Adds port flag.

* Changes the flag for clients.

* Adds package comments.
---
 examples/features/deadline/client/main.go     |  6 ++---
 examples/features/errors/README.md            | 26 ++++++++++++++++++-
 .../errors}/client/main.go                    |  8 +++++-
 .../errors}/server/main.go                    | 13 ++++++----
 examples/rpc_errors/README.md                 | 25 ------------------
 5 files changed, 43 insertions(+), 35 deletions(-)
 rename examples/{rpc_errors => features/errors}/client/main.go (88%)
 rename examples/{rpc_errors => features/errors}/server/main.go (91%)
 delete mode 100644 examples/rpc_errors/README.md

diff --git a/examples/features/deadline/client/main.go b/examples/features/deadline/client/main.go
index d19178cc..0e262613 100644
--- a/examples/features/deadline/client/main.go
+++ b/examples/features/deadline/client/main.go
@@ -32,6 +32,8 @@ import (
 	"google.golang.org/grpc/status"
 )
 
+var addr = flag.String("addr", "localhost:50052", "the address to connect to")
+
 func unaryCall(c pb.EchoClient, requestID int, message string, want codes.Code) {
 	// Creates a context with a one second deadline for the RPC.
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
@@ -68,11 +70,9 @@ func streamingCall(c pb.EchoClient, requestID int, message string, want codes.Co
 }
 
 func main() {
-	port := flag.Int("port", 50052, "port number")
 	flag.Parse()
 
-	target := fmt.Sprintf("localhost:%v", *port)
-	conn, err := grpc.Dial(target, grpc.WithInsecure())
+	conn, err := grpc.Dial(*addr, grpc.WithInsecure())
 	if err != nil {
 		log.Fatalf("did not connect: %v", err)
 	}
diff --git a/examples/features/errors/README.md b/examples/features/errors/README.md
index b45b30e1..62eee83d 100644
--- a/examples/features/errors/README.md
+++ b/examples/features/errors/README.md
@@ -1 +1,25 @@
-Please see [examples/rpc_errors](../../rpc_errors).
+# Description
+
+This example demonstrates the use of status details in grpc errors.
+
+# Run the sample code
+
+Run the server:
+
+```sh
+$ go run ./server/main.go
+```
+Then run the client in another terminal:
+
+```sh
+$ go run ./client/main.go
+```
+
+It should succeed and print the greeting it received from the server.
+Then run the client again:
+
+```sh
+$ go run ./client/main.go
+```
+
+This time, it should fail by printing error status details that it received from the server.
diff --git a/examples/rpc_errors/client/main.go b/examples/features/errors/client/main.go
similarity index 88%
rename from examples/rpc_errors/client/main.go
rename to examples/features/errors/client/main.go
index daccb1ef..4bacff5f 100644
--- a/examples/rpc_errors/client/main.go
+++ b/examples/features/errors/client/main.go
@@ -16,10 +16,12 @@
  *
  */
 
+// Binary client is an example client.
 package main
 
 import (
 	"context"
+	"flag"
 	"log"
 	"os"
 	"time"
@@ -30,9 +32,13 @@ import (
 	"google.golang.org/grpc/status"
 )
 
+var addr = flag.String("addr", "localhost:50052", "the address to connect to")
+
 func main() {
+	flag.Parse()
+
 	// Set up a connection to the server.
-	conn, err := grpc.Dial("localhost:50051", grpc.WithInsecure())
+	conn, err := grpc.Dial(*addr, grpc.WithInsecure())
 	if err != nil {
 		log.Fatalf("did not connect: %v", err)
 	}
diff --git a/examples/rpc_errors/server/main.go b/examples/features/errors/server/main.go
similarity index 91%
rename from examples/rpc_errors/server/main.go
rename to examples/features/errors/server/main.go
index 7593aabd..d306c4eb 100644
--- a/examples/rpc_errors/server/main.go
+++ b/examples/features/errors/server/main.go
@@ -16,10 +16,12 @@
  *
  */
 
+// Binary server is an example server.
 package main
 
 import (
 	"context"
+	"flag"
 	"fmt"
 	"log"
 	"net"
@@ -32,9 +34,7 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-const (
-	port = ":50051"
-)
+var port = flag.Int("port", 50052, "port number")
 
 // server is used to implement helloworld.GreeterServer.
 type server struct {
@@ -67,11 +67,14 @@ func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloRe
 }
 
 func main() {
-	log.Printf("server starting on port %s...", port)
-	lis, err := net.Listen("tcp", port)
+	flag.Parse()
+
+	address := fmt.Sprintf(":%v", *port)
+	lis, err := net.Listen("tcp", address)
 	if err != nil {
 		log.Fatalf("failed to listen: %v", err)
 	}
+
 	s := grpc.NewServer()
 	pb.RegisterGreeterServer(s, &server{count: make(map[string]int)})
 	if err := s.Serve(lis); err != nil {
diff --git a/examples/rpc_errors/README.md b/examples/rpc_errors/README.md
deleted file mode 100644
index 62eee83d..00000000
--- a/examples/rpc_errors/README.md
+++ /dev/null
@@ -1,25 +0,0 @@
-# Description
-
-This example demonstrates the use of status details in grpc errors.
-
-# Run the sample code
-
-Run the server:
-
-```sh
-$ go run ./server/main.go
-```
-Then run the client in another terminal:
-
-```sh
-$ go run ./client/main.go
-```
-
-It should succeed and print the greeting it received from the server.
-Then run the client again:
-
-```sh
-$ go run ./client/main.go
-```
-
-This time, it should fail by printing error status details that it received from the server.