fix latest CI breakages by forking code from grpc-go's interop/testing

Also moves testing package to internal/testing

internal/testing/cmd/bankdemo/main.go

@@ -0,0 +1,168 @@
+package main
+
+//go:generate protoc --go_out=plugins=grpc:./ bank.proto support.proto
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"os"
+	"os/signal"
+	"sync/atomic"
+	"syscall"
+	"time"
+
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/peer"
+	"google.golang.org/grpc/reflection"
+	"google.golang.org/grpc/status"
+)
+
+func main() {
+	grpclog.SetLoggerV2(grpclog.NewLoggerV2(os.Stdout, os.Stdout, os.Stderr))
+
+	port := flag.Int("port", 12345, "The port on which bankdemo gRPC server will listen.")
+	datafile := flag.String("datafile", "accounts.json", "The path and filename to which bank account data is saved and from which data will be loaded.")
+	flag.Parse()
+
+	// create the server and load initial dataset
+	ctx, cancel := context.WithCancel(context.Background())
+	s := &svr{
+		datafile: *datafile,
+		ctx:      ctx,
+		cancel:   cancel,
+	}
+	if err := s.load(); err != nil {
+		panic(err)
+	}
+
+	l, err := net.Listen("tcp", fmt.Sprintf("127.0.0.1:%d", *port))
+	if err != nil {
+		panic(err)
+	}
+
+	grpcSvr := gRPCServer()
+
+	// Register gRPC service implementations
+	bankSvc := bankServer{
+		allAccounts: &s.allAccounts,
+	}
+	RegisterBankServer(grpcSvr, &bankSvc)
+
+	chatSvc := chatServer{
+		chatsBySession: map[string]*session{},
+	}
+	RegisterSupportServer(grpcSvr, &chatSvc)
+
+	go s.bgSaver()
+
+	// don't forget to include server reflection support!
+	reflection.Register(grpcSvr)
+
+	defer func() {
+		cancel()
+		s.flush()
+	}()
+
+	// trap SIGINT / SIGTERM to exit cleanly
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGINT)
+	signal.Notify(c, syscall.SIGTERM)
+	go func() {
+		<-c
+		fmt.Println("Shutting down...")
+		grpcSvr.GracefulStop()
+	}()
+
+	grpclog.Infof("server starting, listening on %v", l.Addr())
+	if err := grpcSvr.Serve(l); err != nil {
+		panic(err)
+	}
+}
+
+func gRPCServer() *grpc.Server {
+	var reqCounter uint64
+	return grpc.NewServer(
+		grpc.UnaryInterceptor(func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+			reqID := atomic.AddUint64(&reqCounter, 1)
+			var client string
+			if p, ok := peer.FromContext(ctx); ok {
+				client = p.Addr.String()
+			} else {
+				client = "?"
+			}
+			grpclog.Infof("request %d started for %s from %s", reqID, info.FullMethod, client)
+
+			rsp, err := handler(ctx, req)
+
+			stat, _ := status.FromError(err)
+			grpclog.Infof("request %d completed for %s from %s: %v %s", reqID, info.FullMethod, client, stat.Code(), stat.Message())
+			return rsp, err
+
+		}),
+		grpc.StreamInterceptor(func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+			reqID := atomic.AddUint64(&reqCounter, 1)
+			var client string
+			if p, ok := peer.FromContext(ss.Context()); ok {
+				client = p.Addr.String()
+			} else {
+				client = "?"
+			}
+			grpclog.Infof("request %d started for %s from %s", reqID, info.FullMethod, client)
+
+			err := handler(srv, ss)
+
+			stat, _ := status.FromError(err)
+			grpclog.Infof("request %d completed for %s from %s: %v %s", reqID, info.FullMethod, client, stat.Code(), stat.Message())
+			return err
+		}))
+}
+
+type svr struct {
+	datafile    string
+	ctx         context.Context
+	cancel      context.CancelFunc
+	allAccounts accounts
+}
+
+func (s *svr) load() error {
+	accts, err := ioutil.ReadFile(s.datafile)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	if len(accts) == 0 {
+		s.allAccounts.AccountNumbersByCustomer = map[string][]uint64{}
+		s.allAccounts.AccountsByNumber = map[uint64]*account{}
+	} else if err := json.Unmarshal(accts, &s.allAccounts); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (s *svr) bgSaver() {
+	ticker := time.NewTicker(5 * time.Second)
+	for {
+		select {
+		case <-ticker.C:
+			s.flush()
+		case <-s.ctx.Done():
+			ticker.Stop()
+			return
+		}
+	}
+}
+
+func (s *svr) flush() {
+	accounts := s.allAccounts.clone()
+
+	if b, err := json.Marshal(accounts); err != nil {
+		grpclog.Errorf("failed to save data to %q", s.datafile)
+	} else if err := ioutil.WriteFile(s.datafile, b, 0666); err != nil {
+		grpclog.Errorf("failed to save data to %q", s.datafile)
+	}
+}