common/prpc, tools/cmd/cproto: prpc client

common/prpc/client_test.go

Index: common/prpc/client_test.go
diff --git a/common/prpc/client_test.go b/common/prpc/client_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..4f8e0b912434a6b9e6b47473ad3b58f501a1c7d9
--- /dev/null
+++ b/common/prpc/client_test.go
@@ -0,0 +1,200 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package prpc
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+
+	"github.com/luci/luci-go/common/logging"
+	"github.com/luci/luci-go/common/logging/memlogger"
+	"github.com/luci/luci-go/common/retry"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func sayHello(c C) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		c.So(r.Method, ShouldEqual, "POST")
+		c.So(r.URL.Path, ShouldEqual, "/prpc/prpc.Greeter/SayHello")
+		c.So(r.Header.Get("Accept"), ShouldEqual, "application/prpc")
+		c.So(r.Header.Get("Content-Type"), ShouldEqual, "application/prpc")
+		c.So(r.Header.Get("User-Agent"), ShouldEqual, "prpc-test")
+
+		reqBody, err := ioutil.ReadAll(r.Body)
+		c.So(err, ShouldBeNil)
+
+		var req HelloRequest
+		err = proto.Unmarshal(reqBody, &req)
+		c.So(err, ShouldBeNil)
+
+		res := HelloReply{"Hello " + req.Name}
+		buf, err := proto.Marshal(&res)
+		c.So(err, ShouldBeNil)
+
+		w.Header().Set(HeaderGRPCCode, strconv.Itoa(int(codes.OK)))
+		_, err = w.Write(buf)
+		c.So(err, ShouldBeNil)
+	}
+}
+
+func transientErrors(count int, then http.Handler) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if count > 0 {
+			count--
+			w.Header().Set(HeaderGRPCCode, strconv.Itoa(int(codes.Internal)))
+			w.WriteHeader(http.StatusInternalServerError)
+			fmt.Fprintln(w, "Server misbehaved")
+			return
+		}
+		then.ServeHTTP(w, r)
+	}
+}
+
+func shouldHaveMessagesLike(actual interface{}, expected ...interface{}) string {
+	log := actual.(*memlogger.MemLogger)
+	msgs := log.Messages()
+
+	So(msgs, ShouldHaveLength, len(expected))
+	for i, actual := range msgs {
+		expected := expected[i].(memlogger.LogEntry)
+		So(actual.Level, ShouldEqual, expected.Level)
+		So(actual.Msg, ShouldContainSubstring, expected.Msg)
+	}
+	return ""
+}
+
+func TestClient(t *testing.T) {
+	t.Parallel()
+
+	Convey("Client", t, func() {
+		setUp := func(h http.HandlerFunc) (*Client, *httptest.Server) {
+			server := httptest.NewServer(h)
+			client := &Client{
+				Host: strings.TrimPrefix(server.URL, "http://"),
+				Options: &Options{
+					Retry: func() retry.Iterator {
+						return &retry.ExponentialBackoff{
+							Limited: retry.Limited{
+								Retries: 3,
+								Delay:   time.Millisecond,
+							},
+						}
+					},
+					Insecure:  true,
+					UserAgent: "prpc-test",
+				},
+			}
+			return client, server
+		}
+
+		ctx := memlogger.Use(context.Background())
+		log := logging.Get(ctx).(*memlogger.MemLogger)
+		expectedCallLogEntry := func(c *Client) memlogger.LogEntry {
+			return memlogger.LogEntry{
+				Level: logging.Debug,
+				Msg:   fmt.Sprintf("RPC %s/prpc.Greeter.SayHello", c.Host),
+			}
+		}
+
+		req := &HelloRequest{"John"}
+		res := &HelloReply{}
+
+		Convey("Call", func() {
+			Convey("Works", func(c C) {
+				client, server := setUp(sayHello(c))
+				defer server.Close()
+
+				err := client.Call(ctx, "prpc.Greeter", "SayHello", req, res)
+				So(err, ShouldBeNil)
+				So(res.Message, ShouldEqual, "Hello John")
+
+				So(log, shouldHaveMessagesLike, expectedCallLogEntry(client))
+			})
+
+			Convey("HTTP 500 x2", func(c C) {
+				client, server := setUp(transientErrors(2, sayHello(c)))
+				defer server.Close()
+
+				err := client.Call(ctx, "prpc.Greeter", "SayHello", req, res)
+				So(err, ShouldBeNil)
+				So(res.Message, ShouldEqual, "Hello John")
+
+				So(log, shouldHaveMessagesLike,
+					expectedCallLogEntry(client),
+					memlogger.LogEntry{Level: logging.Warning, Msg: "RPC failed transiently. Will retry in 1ms"},
+
+					expectedCallLogEntry(client),
+					memlogger.LogEntry{Level: logging.Warning, Msg: "RPC failed transiently. Will retry in 2ms"},
+
+					expectedCallLogEntry(client),
+				)
+			})
+
+			Convey("HTTP 500 many", func(c C) {
+				client, server := setUp(transientErrors(10, sayHello(c)))
+				defer server.Close()
+
+				err := client.Call(ctx, "prpc.Greeter", "SayHello", req, res)
+				So(grpc.Code(err), ShouldEqual, codes.Internal)
+				So(grpc.ErrorDesc(err), ShouldEqual, "Server misbehaved")
+
+				So(log, shouldHaveMessagesLike,
+					expectedCallLogEntry(client),
+					memlogger.LogEntry{Level: logging.Warning, Msg: "RPC failed transiently. Will retry in 1ms"},
+
+					expectedCallLogEntry(client),
+					memlogger.LogEntry{Level: logging.Warning, Msg: "RPC failed transiently. Will retry in 2ms"},
+
+					expectedCallLogEntry(client),
+					memlogger.LogEntry{Level: logging.Warning, Msg: "RPC failed transiently. Will retry in 4ms"},
+
+					expectedCallLogEntry(client),
+					memlogger.LogEntry{Level: logging.Warning, Msg: "RPC failed permanently"},
+				)
+			})
+
+			Convey("Forbidden", func(c C) {
+				client, server := setUp(func(w http.ResponseWriter, r *http.Request) {
+					w.Header().Set(HeaderGRPCCode, strconv.Itoa(int(codes.PermissionDenied)))
+					w.WriteHeader(http.StatusForbidden)
+					fmt.Fprintln(w, "Access denied")
+				})
+				defer server.Close()
+
+				err := client.Call(ctx, "prpc.Greeter", "SayHello", req, res)
+				So(grpc.Code(err), ShouldEqual, codes.PermissionDenied)
+				So(grpc.ErrorDesc(err), ShouldEqual, "Access denied")
+
+				So(log, shouldHaveMessagesLike,
+					expectedCallLogEntry(client),
+					memlogger.LogEntry{Level: logging.Warning, Msg: "RPC failed permanently"},
+				)
+			})
+
+			Convey(HeaderGRPCCode, func(c C) {
+				client, server := setUp(func(w http.ResponseWriter, r *http.Request) {
+					w.Header().Set(HeaderGRPCCode, strconv.Itoa(int(codes.Canceled)))
+					w.WriteHeader(http.StatusBadRequest)
+				})
+				defer server.Close()
+
+				err := client.Call(ctx, "prpc.Greeter", "SayHello", req, res)
+				So(grpc.Code(err), ShouldEqual, codes.Canceled)
+			})
+		})
+	})
+}