Activate xDS support in grpcurl (#137)

* use wrapped TransportCredentials instead of handling handshake in Dialer, so that grpc library will use correct :scheme
* support -authority for TLS conns; now effectively supercedes -servername flag

.gitignore

@@ -1 +1,2 @@
 dist/
+VERSION

.travis.yml

@@ -3,15 +3,19 @@ sudo: false
 
 matrix:
   include:
-    - go: "1.9"
-    - go: "1.10"
-      env: VET=1
-    - go: "1.11"
-      env: GO111MODULE=off
-    - go: "1.11"
+    - go: 1.9.x
+    - go: 1.10.x
+    - go: 1.11.x
+      env:
+      - GO111MODULE=off
+      - VET=1
+    - go: 1.11.x
+      env: GO111MODULE=on
+    - go: 1.12.x
+      env: GO111MODULE=off
+    - go: 1.12.x
       env: GO111MODULE=on
-    - go: "1.12"
     - go: tip
 
 script:
-  - if [[ "$VET" = 1 ]]; then make; else make deps test; fi
+  - if [[ "$VET" = 1 ]]; then make ci; else make deps test; fi

Dockerfile

@@ -0,0 +1,33 @@
+FROM golang:1.11.10-alpine as builder
+MAINTAINER FullStory Engineering
+
+# currently, a module build requires gcc (so Go tool can build
+# module-aware versions of std library; it ships only w/ the
+# non-module versions)
+RUN apk update && apk add --no-cache ca-certificates git gcc g++ libc-dev
+# create non-privileged group and user
+RUN addgroup -S grpcurl && adduser -S grpcurl -G grpcurl
+
+WORKDIR /tmp/fullstorydev/grpcurl
+# copy just the files/sources we need to build grpcurl
+COPY VERSION *.go go.* /tmp/fullstorydev/grpcurl/
+COPY cmd /tmp/fullstorydev/grpcurl/cmd
+# and build a completely static binary (so we can use
+# scratch as basis for the final image)
+ENV CGO_ENABLED=0
+ENV GOOS=linux
+ENV GOARCH=amd64
+ENV GO111MODULE=on
+RUN go build -o /grpcurl \
+    -ldflags "-w -extldflags \"-static\" -X \"main.version=$(cat VERSION)\"" \
+    ./cmd/grpcurl
+
+# New FROM so we have a nice'n'tiny image
+FROM scratch
+WORKDIR /
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
+COPY --from=builder /etc/passwd /etc/passwd
+COPY --from=builder /grpcurl /bin/grpcurl
+USER grpcurl
+
+ENTRYPOINT ["/bin/grpcurl"]

Makefile

@@ -6,7 +6,7 @@ dev_build_version=$(shell git describe --tags --always --dirty)
 # they are just too noisy to be a requirement for a CI -- we don't even *want*
 # to fix some of the things they consider to be violations.
 .PHONY: ci
-ci: deps checkgofmt vet staticcheck unused ineffassign predeclared test
+ci: deps checkgofmt vet staticcheck ineffassign predeclared test
 
 .PHONY: deps
 deps:
@@ -25,6 +25,12 @@ release:
 	@GO111MODULE=off go get github.com/goreleaser/goreleaser
 	goreleaser --rm-dist
 
+.PHONY: docker
+docker:
+	@echo $(dev_build_version) > VERSION
+	docker build -t fullstorydev/grpcurl:$(dev_build_version) .
+	@rm VERSION
+
 .PHONY: checkgofmt
 checkgofmt:
 	gofmt -s -l .
@@ -47,12 +53,7 @@ vet:
 .PHONY: staticcheck
 staticcheck:
 	@go get honnef.co/go/tools/cmd/staticcheck
-	staticcheck -ignore github.com/fullstorydev/grpcurl/tls_settings_test.go:SA1019 ./...
-
-.PHONY: unused
-unused:
-	@go get honnef.co/go/tools/cmd/unused
-	unused ./...
+	staticcheck ./...
 
 .PHONY: ineffassign
 ineffassign:

cmd/grpcurl/grpcurl.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -22,6 +23,9 @@ import (
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
 	reflectpb "google.golang.org/grpc/reflection/grpc_reflection_v1alpha"
+
+	// Register gzip compressor so compressed responses will work:
+	_ "google.golang.org/grpc/encoding/gzip"
 )
 
 var version = "dev build <no version set>"
@@ -51,15 +55,27 @@ var (
 	key = flags.String("key", "", prettify(`
 		File containing client private key, to present to the server. Not valid
 		with -plaintext option. Must also provide -cert option.`))
-	protoset    multiString
-	protoFiles  multiString
-	importPaths multiString
-	addlHeaders multiString
-	rpcHeaders  multiString
-	reflHeaders multiString
-	authority   = flags.String("authority", "", prettify(`
-		Value of :authority pseudo-header to be use with underlying HTTP/2
-		requests. It defaults to the given address.`))
+	protoset      multiString
+	protoFiles    multiString
+	importPaths   multiString
+	addlHeaders   multiString
+	rpcHeaders    multiString
+	reflHeaders   multiString
+	expandHeaders = flags.Bool("expand-headers", false, prettify(`
+		If set, headers may use '${NAME}' syntax to reference environment
+		variables. These will be expanded to the actual environment variable
+		value before sending to the server. For example, if there is an
+		environment variable defined like FOO=bar, then a header of
+		'key: ${FOO}' would expand to 'key: bar'. This applies to -H,
+		-rpc-header, and -reflect-header options. No other expansion/escaping is
+		performed. This can be used to supply credentials/secrets without having
+		to put them in command-line arguments.`))
+	authority = flags.String("authority", "", prettify(`
+		The authoritative name of the remote server. This value is passed as the
+		value of the ":authority" pseudo-header in the HTTP/2 protocol. When TLS
+		is used, this will also be used as the server name when verifying the
+		server's certificate. It defaults to the address that is provided in the
+		positional arguments.`))
 	data = flags.String("d", "", prettify(`
 		Data for request contents. If the value is '@' then the request contents
 		are read from stdin. For calls that accept a stream of requests, the
@@ -92,12 +108,24 @@ var (
 		will accept. If not specified, defaults to 4,194,304 (4 megabytes).`))
 	emitDefaults = flags.Bool("emit-defaults", false, prettify(`
 		Emit default values for JSON-encoded responses.`))
+	protosetOut = flags.String("protoset-out", "", prettify(`
+		The name of a file to be written that will contain a FileDescriptorSet
+		proto. With the list and describe verbs, the listed or described
+		elements and their transitive dependencies will be written to the named
+		file if this option is given. When invoking an RPC and this option is
+		given, the method being invoked and its transitive dependencies will be
+		included in the output file.`))
 	msgTemplate = flags.Bool("msg-template", false, prettify(`
 		When describing messages, show a template of input data.`))
 	verbose = flags.Bool("v", false, prettify(`
 		Enable verbose output.`))
 	serverName = flags.String("servername", "", prettify(`
-		Override server name when validating TLS certificate.`))
+		Override server name when validating TLS certificate. This flag is
+		ignored if -plaintext or -insecure is used.
+		NOTE: Prefer -authority. This flag may be removed in the future. It is
+		an error to use both -authority and -servername (though this will be
+		permitted if they are both set to the same value, to increase backwards
+		compatibility with earlier releases that allowed both to be set).`))
 )
 
 func init() {
@@ -161,7 +189,7 @@ func main() {
 		os.Exit(0)
 	}
 	if *printVersion {
-		fmt.Fprintf(os.Stderr, "%s %s\n", os.Args[0], version)
+		fmt.Fprintf(os.Stderr, "%s %s\n", filepath.Base(os.Args[0]), version)
 		os.Exit(0)
 	}
 
@@ -285,9 +313,6 @@ func main() {
 		if *maxMsgSz > 0 {
 			opts = append(opts, grpc.WithDefaultCallOptions(grpc.MaxCallRecvMsgSize(*maxMsgSz)))
 		}
-		if *authority != "" {
-			opts = append(opts, grpc.WithAuthority(*authority))
-		}
 		var creds credentials.TransportCredentials
 		if !*plaintext {
 			var err error
@@ -295,11 +320,27 @@ func main() {
 			if err != nil {
 				fail(err, "Failed to configure transport credentials")
 			}
-			if *serverName != "" {
-				if err := creds.OverrideServerName(*serverName); err != nil {
-					fail(err, "Failed to override server name as %q", *serverName)
+
+			// can use either -servername or -authority; but not both
+			if *serverName != "" && *authority != "" {
+				if *serverName == *authority {
+					warn("Both -servername and -authority are present; prefer only -authority.")
+				} else {
+					fail(nil, "Cannot specify different values for -servername and -authority.")
 				}
 			}
+			overrideName := *serverName
+			if overrideName == "" {
+				overrideName = *authority
+			}
+
+			if overrideName != "" {
+				if err := creds.OverrideServerName(overrideName); err != nil {
+					fail(err, "Failed to override server name as %q", overrideName)
+				}
+			}
+		} else if *authority != "" {
+			opts = append(opts, grpc.WithAuthority(*authority))
 		}
 		network := "tcp"
 		if isUnixSocket != nil && isUnixSocket() {
@@ -312,6 +353,22 @@ func main() {
 		return cc
 	}
 
+	if *expandHeaders {
+		var err error
+		addlHeaders, err = grpcurl.ExpandHeaders(addlHeaders)
+		if err != nil {
+			fail(err, "Failed to expand additional headers")
+		}
+		rpcHeaders, err = grpcurl.ExpandHeaders(rpcHeaders)
+		if err != nil {
+			fail(err, "Failed to expand rpc headers")
+		}
+		reflHeaders, err = grpcurl.ExpandHeaders(reflHeaders)
+		if err != nil {
+			fail(err, "Failed to expand reflection headers")
+		}
+	}
+
 	var cc *grpc.ClientConn
 	var descSource grpcurl.DescriptorSource
 	var refClient *grpcreflect.Client
@@ -366,6 +423,9 @@ func main() {
 					fmt.Printf("%s\n", svc)
 				}
 			}
+			if err := writeProtoset(descSource, svcs...); err != nil {
+				fail(err, "Failed to write protoset to %s", *protosetOut)
+			}
 		} else {
 			methods, err := grpcurl.ListMethods(descSource, symbol)
 			if err != nil {
@@ -378,6 +438,9 @@ func main() {
 					fmt.Printf("%s\n", m)
 				}
 			}
+			if err := writeProtoset(descSource, symbol); err != nil {
+				fail(err, "Failed to write protoset to %s", *protosetOut)
+			}
 		}
 
 	} else if describe {
@@ -478,6 +541,9 @@ func main() {
 				fmt.Println(str)
 			}
 		}
+		if err := writeProtoset(descSource, symbols...); err != nil {
+			fail(err, "Failed to write protoset to %s", *protosetOut)
+		}
 
 	} else {
 		// Invoke an RPC
@@ -518,7 +584,7 @@ func main() {
 			fmt.Printf("Sent %d request%s and received %d response%s\n", reqCount, reqSuffix, h.NumResponses, respSuffix)
 		}
 		if h.Status.Code() != codes.OK {
-			fmt.Fprintf(os.Stderr, "ERROR:\n  Code: %s\n  Message: %s\n", h.Status.Code().String(), h.Status.Message())
+			grpcurl.PrintStatus(os.Stderr, h.Status, formatter)
 			exit(1)
 		}
 	}
@@ -594,3 +660,15 @@ func fail(err error, msg string, args ...interface{}) {
 		exit(2)
 	}
 }
+
+func writeProtoset(descSource grpcurl.DescriptorSource, symbols ...string) error {
+	if *protosetOut == "" {
+		return nil
+	}
+	f, err := os.Create(*protosetOut)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	return grpcurl.WriteProtoset(f, descSource, symbols...)
+}

desc_source.go

@@ -3,6 +3,7 @@ package grpcurl
 import (
 	"errors"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"sync"
 
@@ -58,9 +59,14 @@ func DescriptorSourceFromProtoSets(fileNames ...string) (DescriptorSource, error
 // whose contents are Protocol Buffer source files. The given importPaths are used to locate
 // any imported files.
 func DescriptorSourceFromProtoFiles(importPaths []string, fileNames ...string) (DescriptorSource, error) {
+	fileNames, err := protoparse.ResolveFilenames(importPaths, fileNames...)
+	if err != nil {
+		return nil, err
+	}
 	p := protoparse.Parser{
-		ImportPaths:      importPaths,
-		InferImportPaths: len(importPaths) == 0,
+		ImportPaths:           importPaths,
+		InferImportPaths:      len(importPaths) == 0,
+		IncludeSourceCodeInfo: true,
 	}
 	fds, err := p.ParseFiles(fileNames...)
 	if err != nil {
@@ -109,7 +115,7 @@ func resolveFileDescriptor(unresolved map[string]*descpb.FileDescriptorProto, re
 	return result, nil
 }
 
-// DescriptorSourceFromFileDescriptorSet creates a DescriptorSource that is backed by the given
+// DescriptorSourceFromFileDescriptors creates a DescriptorSource that is backed by the given
 // file descriptors
 func DescriptorSourceFromFileDescriptors(files ...*desc.FileDescriptor) (DescriptorSource, error) {
 	fds := map[string]*desc.FileDescriptor{}
@@ -246,3 +252,53 @@ func reflectionSupport(err error) error {
 	}
 	return err
 }
+
+// WriteProtoset will use the given descriptor source to resolve all of the given
+// symbols and write a proto file descriptor set with their definitions to the
+// given output. The output will include descriptors for all files in which the
+// symbols are defined as well as their transitive dependencies.
+func WriteProtoset(out io.Writer, descSource DescriptorSource, symbols ...string) error {
+	// compute set of file descriptors
+	filenames := make([]string, 0, len(symbols))
+	fds := make(map[string]*desc.FileDescriptor, len(symbols))
+	for _, sym := range symbols {
+		d, err := descSource.FindSymbol(sym)
+		if err != nil {
+			return fmt.Errorf("failed to find descriptor for %q: %v", sym, err)
+		}
+		fd := d.GetFile()
+		if _, ok := fds[fd.GetName()]; !ok {
+			fds[fd.GetName()] = fd
+			filenames = append(filenames, fd.GetName())
+		}
+	}
+	// now expand that to include transitive dependencies in topologically sorted
+	// order (such that file always appears after its dependencies)
+	expandedFiles := make(map[string]struct{}, len(fds))
+	allFilesSlice := make([]*descpb.FileDescriptorProto, 0, len(fds))
+	for _, filename := range filenames {
+		allFilesSlice = addFilesToSet(allFilesSlice, expandedFiles, fds[filename])
+	}
+	// now we can serialize to file
+	b, err := proto.Marshal(&descpb.FileDescriptorSet{File: allFilesSlice})
+	if err != nil {
+		return fmt.Errorf("failed to serialize file descriptor set: %v", err)
+	}
+	if _, err := out.Write(b); err != nil {
+		return fmt.Errorf("failed to write file descriptor set: %v", err)
+	}
+	return nil
+}
+
+func addFilesToSet(allFiles []*descpb.FileDescriptorProto, expanded map[string]struct{}, fd *desc.FileDescriptor) []*descpb.FileDescriptorProto {
+	if _, ok := expanded[fd.GetName()]; ok {
+		// already seen this one
+		return allFiles
+	}
+	expanded[fd.GetName()] = struct{}{}
+	// add all dependencies first
+	for _, dep := range fd.GetDependencies() {
+		allFiles = addFilesToSet(allFiles, expanded, dep)
+	}
+	return append(allFiles, fd.AsFileDescriptorProto())
+}

desc_source_test.go

@@ -0,0 +1,62 @@
+package grpcurl
+
+import (
+	"bytes"
+	"io/ioutil"
+	"testing"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/protoc-gen-go/descriptor"
+)
+
+func TestWriteProtoset(t *testing.T) {
+	exampleProtoset, err := loadProtoset("./testing/example.protoset")
+	if err != nil {
+		t.Fatalf("failed to load example.protoset: %v", err)
+	}
+	testProtoset, err := loadProtoset("./testing/test.protoset")
+	if err != nil {
+		t.Fatalf("failed to load test.protoset: %v", err)
+	}
+
+	mergedProtoset := &descriptor.FileDescriptorSet{
+		File: append(exampleProtoset.File, testProtoset.File...),
+	}
+
+	descSrc, err := DescriptorSourceFromFileDescriptorSet(mergedProtoset)
+	if err != nil {
+		t.Fatalf("failed to create descriptor source: %v", err)
+	}
+
+	checkWriteProtoset(t, descSrc, exampleProtoset, "TestService")
+	checkWriteProtoset(t, descSrc, testProtoset, "grpc.testing.TestService")
+	checkWriteProtoset(t, descSrc, mergedProtoset, "TestService", "grpc.testing.TestService")
+}
+
+func loadProtoset(path string) (*descriptor.FileDescriptorSet, error) {
+	b, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	var protoset descriptor.FileDescriptorSet
+	if err := proto.Unmarshal(b, &protoset); err != nil {
+		return nil, err
+	}
+	return &protoset, nil
+}
+
+func checkWriteProtoset(t *testing.T, descSrc DescriptorSource, protoset *descriptor.FileDescriptorSet, symbols ...string) {
+	var buf bytes.Buffer
+	if err := WriteProtoset(&buf, descSrc, symbols...); err != nil {
+		t.Fatalf("failed to write protoset: %v", err)
+	}
+
+	var result descriptor.FileDescriptorSet
+	if err := proto.Unmarshal(buf.Bytes(), &result); err != nil {
+		t.Fatalf("failed to unmarshal written protoset: %v", err)
+	}
+
+	if !proto.Equal(protoset, &result) {
+		t.Fatalf("written protoset not equal to input:\nExpecting: %s\nActual: %s", protoset, &result)
+	}
+}

format.go

@@ -3,14 +3,19 @@ package grpcurl
 import (
 	"bufio"
 	"bytes"
+	"encoding/base64"
 	"encoding/json"
 	"fmt"
 	"io"
+	"reflect"
+	"strings"
+	"sync"
 
 	"github.com/golang/protobuf/jsonpb"
 	"github.com/golang/protobuf/proto"
 	"github.com/jhump/protoreflect/desc"
 	"github.com/jhump/protoreflect/dynamic"
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/status"
 )
@@ -142,6 +147,8 @@ type textFormatter struct {
 	numFormatted int
 }
 
+var protoTextMarshaler = proto.TextMarshaler{ExpandAny: true}
+
 func (tf *textFormatter) format(m proto.Message) (string, error) {
 	var buf bytes.Buffer
 	if tf.useSeparator && tf.numFormatted > 0 {
@@ -166,7 +173,7 @@ func (tf *textFormatter) format(m proto.Message) (string, error) {
 		if _, err := buf.Write(b); err != nil {
 			return "", err
 		}
-	} else if err := proto.MarshalText(&buf, m); err != nil {
+	} else if err := protoTextMarshaler.Marshal(&buf, m); err != nil {
 		return "", err
 	}
 
@@ -188,24 +195,153 @@ const (
 	FormatText = Format("text")
 )
 
-func anyResolver(source DescriptorSource) (jsonpb.AnyResolver, error) {
-	// TODO: instead of pro-actively downloading file descriptors to
-	// build a dynamic resolver, it would be better if the resolver
-	// impl was lazy, and simply downloaded the descriptors as needed
-	// when asked to resolve a particular type URL
-
-	// best effort: build resolver with whatever files we can
-	// load, ignoring any errors
-	files, _ := GetAllFiles(source)
-
-	var er dynamic.ExtensionRegistry
-	for _, fd := range files {
-		er.AddExtensionsFromFile(fd)
-	}
-	mf := dynamic.NewMessageFactoryWithExtensionRegistry(&er)
-	return dynamic.AnyResolver(mf, files...), nil
+// AnyResolverFromDescriptorSource returns an AnyResolver that will search for
+// types using the given descriptor source.
+func AnyResolverFromDescriptorSource(source DescriptorSource) jsonpb.AnyResolver {
+	return &anyResolver{source: source}
 }
 
+// AnyResolverFromDescriptorSourceWithFallback returns an AnyResolver that will
+// search for types using the given descriptor source and then fallback to a
+// special message if the type is not found. The fallback type will render to
+// JSON with a "@type" property, just like an Any message, but also with a
+// custom "@value" property that includes the binary encoded payload.
+func AnyResolverFromDescriptorSourceWithFallback(source DescriptorSource) jsonpb.AnyResolver {
+	res := anyResolver{source: source}
+	return &anyResolverWithFallback{AnyResolver: &res}
+}
+
+type anyResolver struct {
+	source DescriptorSource
+
+	er dynamic.ExtensionRegistry
+
+	mu       sync.RWMutex
+	mf       *dynamic.MessageFactory
+	resolved map[string]func() proto.Message
+}
+
+func (r *anyResolver) Resolve(typeUrl string) (proto.Message, error) {
+	mname := typeUrl
+	if slash := strings.LastIndex(mname, "/"); slash >= 0 {
+		mname = mname[slash+1:]
+	}
+
+	r.mu.RLock()
+	factory := r.resolved[mname]
+	r.mu.RUnlock()
+
+	// already resolved?
+	if factory != nil {
+		return factory(), nil
+	}
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	// double-check, in case we were racing with another goroutine
+	// that resolved this one
+	factory = r.resolved[mname]
+	if factory != nil {
+		return factory(), nil
+	}
+
+	// use descriptor source to resolve message type
+	d, err := r.source.FindSymbol(mname)
+	if err != nil {
+		return nil, err
+	}
+	md, ok := d.(*desc.MessageDescriptor)
+	if !ok {
+		return nil, fmt.Errorf("unknown message: %s", typeUrl)
+	}
+	// populate any extensions for this message, too
+	if exts, err := r.source.AllExtensionsForType(mname); err != nil {
+		return nil, err
+	} else if err := r.er.AddExtension(exts...); err != nil {
+		return nil, err
+	}
+
+	if r.mf == nil {
+		r.mf = dynamic.NewMessageFactoryWithExtensionRegistry(&r.er)
+	}
+
+	factory = func() proto.Message {
+		return r.mf.NewMessage(md)
+	}
+	if r.resolved == nil {
+		r.resolved = map[string]func() proto.Message{}
+	}
+	r.resolved[mname] = factory
+	return factory(), nil
+}
+
+// anyResolverWithFallback can provide a fallback value for unknown
+// messages that will format itself to JSON using an "@value" field
+// that has the base64-encoded data for the unknown message value.
+type anyResolverWithFallback struct {
+	jsonpb.AnyResolver
+}
+
+func (r anyResolverWithFallback) Resolve(typeUrl string) (proto.Message, error) {
+	msg, err := r.AnyResolver.Resolve(typeUrl)
+	if err == nil {
+		return msg, err
+	}
+
+	// Try "default" resolution logic. This mirrors the default behavior
+	// of jsonpb, which checks to see if the given message name is registered
+	// in the proto package.
+	mname := typeUrl
+	if slash := strings.LastIndex(mname, "/"); slash >= 0 {
+		mname = mname[slash+1:]
+	}
+	mt := proto.MessageType(mname)
+	if mt != nil {
+		return reflect.New(mt.Elem()).Interface().(proto.Message), nil
+	}
+
+	// finally, fallback to a special placeholder that can marshal itself
+	// to JSON using a special "@value" property to show base64-encoded
+	// data for the embedded message
+	return &unknownAny{TypeUrl: typeUrl, Error: fmt.Sprintf("%s is not recognized; see @value for raw binary message data", mname)}, nil
+}
+
+type unknownAny struct {
+	TypeUrl string `json:"@type"`
+	Error   string `json:"@error"`
+	Value   string `json:"@value"`
+}
+
+func (a *unknownAny) MarshalJSONPB(jsm *jsonpb.Marshaler) ([]byte, error) {
+	if jsm.Indent != "" {
+		return json.MarshalIndent(a, "", jsm.Indent)
+	}
+	return json.Marshal(a)
+}
+
+func (a *unknownAny) Unmarshal(b []byte) error {
+	a.Value = base64.StdEncoding.EncodeToString(b)
+	return nil
+}
+
+func (a *unknownAny) Reset() {
+	a.Value = ""
+}
+
+func (a *unknownAny) String() string {
+	b, err := a.MarshalJSONPB(&jsonpb.Marshaler{})
+	if err != nil {
+		return fmt.Sprintf("ERROR: %v", err.Error())
+	}
+	return string(b)
+}
+
+func (a *unknownAny) ProtoMessage() {
+}
+
+var _ proto.Message = (*unknownAny)(nil)
+
 // RequestParserAndFormatterFor returns a request parser and formatter for the
 // given format. The given descriptor source may be used for parsing message
 // data (if needed by the format). The flags emitJSONDefaultFields and
@@ -214,11 +350,8 @@ func anyResolver(source DescriptorSource) (jsonpb.AnyResolver, error) {
 func RequestParserAndFormatterFor(format Format, descSource DescriptorSource, emitJSONDefaultFields, includeTextSeparator bool, in io.Reader) (RequestParser, Formatter, error) {
 	switch format {
 	case FormatJSON:
-		resolver, err := anyResolver(descSource)
-		if err != nil {
-			return nil, nil, fmt.Errorf("error creating message resolver: %v", err)
-		}
-		return NewJSONRequestParser(in, resolver), NewJSONFormatter(emitJSONDefaultFields, resolver), nil
+		resolver := AnyResolverFromDescriptorSource(descSource)
+		return NewJSONRequestParser(in, resolver), NewJSONFormatter(emitJSONDefaultFields, anyResolverWithFallback{AnyResolver: resolver}), nil
 	case FormatText:
 		return NewTextRequestParser(in), NewTextFormatter(includeTextSeparator), nil
 	default:
@@ -295,3 +428,42 @@ func (h *DefaultEventHandler) OnReceiveTrailers(stat *status.Status, md metadata
 		fmt.Fprintf(h.out, "\nResponse trailers received:\n%s\n", MetadataToString(md))
 	}
 }
+
+// PrintStatus prints details about the given status to the given writer. The given
+// formatter is used to print any detail messages that may be included in the status.
+// If the given status has a code of OK, "OK" is printed and that is all. Otherwise,
+// "ERROR:" is printed along with a line showing the code, one showing the message
+// string, and each detail message if any are present. The detail messages will be
+// printed as proto text format or JSON, depending on the given formatter.
+func PrintStatus(w io.Writer, stat *status.Status, formatter Formatter) {
+	if stat.Code() == codes.OK {
+		fmt.Fprintln(w, "OK")
+		return
+	}
+	fmt.Fprintf(w, "ERROR:\n  Code: %s\n  Message: %s\n", stat.Code().String(), stat.Message())
+
+	statpb := stat.Proto()
+	if len(statpb.Details) > 0 {
+		fmt.Fprintf(w, "  Details:\n")
+		for i, det := range statpb.Details {
+			prefix := fmt.Sprintf("  %d)", i+1)
+			fmt.Fprintf(w, "%s\t", prefix)
+			prefix = strings.Repeat(" ", len(prefix)) + "\t"
+
+			output, err := formatter(det)
+			if err != nil {
+				fmt.Fprintf(w, "Error parsing detail message: %v\n", err)
+			} else {
+				lines := strings.Split(output, "\n")
+				for i, line := range lines {
+					if i == 0 {
+						// first line is already indented
+						fmt.Fprintf(w, "%s\n", line)
+					} else {
+						fmt.Fprintf(w, "%s%s\n", prefix, line)
+					}
+				}
+			}
+		}
+	}
+}

go.mod

@@ -1,8 +1,8 @@
 module github.com/fullstorydev/grpcurl
 
 require (
-	github.com/golang/protobuf v1.2.0
-	github.com/jhump/protoreflect v1.2.0
-	golang.org/x/net v0.0.0-20180826012351-8a410e7b638d
-	google.golang.org/grpc v1.19.0
+	github.com/golang/protobuf v1.3.5
+	github.com/jhump/protoreflect v1.5.0
+	golang.org/x/net v0.0.0-20190311183353-d8887717615a
+	google.golang.org/grpc v1.28.0
 )

go.sum

@@ -1,28 +1,58 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
+github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
+github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
+github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
+github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
-github.com/golang/protobuf v1.1.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
-github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
-github.com/jhump/protoreflect v1.2.0 h1:W4HDXsqxgmE9OUmEXWaU2ZoUap/A29J5hW+zRXWbdC8=
-github.com/jhump/protoreflect v1.2.0/go.mod h1:kG/zRVeS2M91gYaCvvUbPkMjjtFQS4qqjcPFzFkh2zE=
+github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.3/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
+github.com/golang/protobuf v1.3.5 h1:F768QJ1E9tib+q5Sc8MkdJi1RxLTbRcTf8LJV56aRls=
+github.com/golang/protobuf v1.3.5/go.mod h1:6O5/vntMXwX2lRkT1hjjk0nAC1IDOTvTlVgjlRvqsdk=
+github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+github.com/jhump/protoreflect v1.5.0 h1:NgpVT+dX71c8hZnxHof2M7QDK7QtohIJ7DYycjnkyfc=
+github.com/jhump/protoreflect v1.5.0/go.mod h1:eaTn3RZAmMBcV0fifFvlm6VHNz3wSkYyXYWUh7ymB74=
+github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
+golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
+golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/net v0.0.0-20180530234432-1e491301e022/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/net v0.0.0-20180826012351-8a410e7b638d h1:g9qWBGx4puODJTMVyoPrpoxPFgVGd+z1DZwjfRu4d0I=
+golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a h1:oWX7TPOiFAMXLq8o0ikBYfCJVlRHBcsciT5bXOrH628=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a h1:1BGLXjeY4akVXGgbC9HugT3Jv3hCI0z56oJR5vAMgBU=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
+golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+golang.org/x/tools v0.0.0-20190524140312-2c0ae7006135/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
-google.golang.org/genproto v0.0.0-20170818100345-ee236bd376b0/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
-google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8 h1:Nw54tB0rB7hY/N0NQvRW8DG4Yk3Q6T9cu9RcFQDu1tc=
+google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
+google.golang.org/genproto v0.0.0-20170818010345-ee236bd376b0/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
+google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55 h1:gSJIx1SDwno+2ElGhA4+qG2zF97qiUzTM+rQ0klBOcE=
+google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55/go.mod h1:DMBHOl98Agz4BDEuKkezgsaosCRResVns1a3J2ZsMNc=
 google.golang.org/grpc v1.8.0/go.mod h1:yo6s7OP7yaDglbqo1J04qKzAhqBH6lvTonzMVmEdcZw=
-google.golang.org/grpc v1.19.0 h1:cfg4PD8YEdSFnm7qLV4++93WcmhH2nIUhMjhdCvl3j8=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
+google.golang.org/grpc v1.23.0/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
+google.golang.org/grpc v1.25.1/go.mod h1:c3i+UQWmh7LiEpx4sFZnkU36qjEYZ0imhYfXVyQciAY=
+google.golang.org/grpc v1.28.0 h1:bO/TA4OxCOummhSf10siHuG7vJOiwh7SpRpFZDkOgl4=
+google.golang.org/grpc v1.28.0/go.mod h1:rpkK4SK4GF4Ach/+MFLZUBavHOvF2JJB5uozKKal+60=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
+honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

grpcurl.go

@@ -15,6 +15,8 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net"
+	"os"
+	"regexp"
 	"sort"
 	"strings"
 
@@ -30,6 +32,7 @@ import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/metadata"
+	_ "google.golang.org/grpc/xds/experimental"
 )
 
 // ListServices uses the given descriptor source to return a sorted list of fully-qualified
@@ -161,6 +164,36 @@ func MetadataFromHeaders(headers []string) metadata.MD {
 	return md
 }
 
+var envVarRegex = regexp.MustCompile(`\${\w+}`)
+
+// ExpandHeaders expands environment variables contained in the header string.
+// If no corresponding environment variable is found an error is returned.
+// TODO: Add escaping for `${`
+func ExpandHeaders(headers []string) ([]string, error) {
+	expandedHeaders := make([]string, len(headers))
+	for idx, header := range headers {
+		if header == "" {
+			continue
+		}
+		results := envVarRegex.FindAllString(header, -1)
+		if len(results) == 0 {
+			expandedHeaders[idx] = headers[idx]
+			continue
+		}
+		expandedHeader := header
+		for _, result := range results {
+			envVarName := result[2 : len(result)-1] // strip leading `${` and trailing `}`
+			envVarValue, ok := os.LookupEnv(envVarName)
+			if !ok {
+				return nil, fmt.Errorf("header %q refers to missing environment variable %q", header, envVarName)
+			}
+			expandedHeader = strings.Replace(expandedHeader, result, envVarValue, -1)
+		}
+		expandedHeaders[idx] = expandedHeader
+	}
+	return expandedHeaders, nil
+}
+
 var base64Codecs = []*base64.Encoding{base64.StdEncoding, base64.URLEncoding, base64.RawStdEncoding, base64.RawURLEncoding}
 
 func decode(val string) (string, error) {
@@ -573,33 +606,44 @@ func BlockingDial(ctx context.Context, network, address string, creds credential
 		}
 	}
 
+	// custom credentials and dialer will notify on error via the
+	// writeResult function
+	if creds != nil {
+		creds = &errSignalingCreds{
+			TransportCredentials: creds,
+			writeResult:          writeResult,
+		}
+	}
 	dialer := func(ctx context.Context, address string) (net.Conn, error) {
+		// NB: We *could* handle the TLS handshake ourselves, in the custom
+		// dialer (instead of customizing both the dialer and the credentials).
+		// But that requires using WithInsecure dial option (so that the gRPC
+		// library doesn't *also* try to do a handshake). And that would mean
+		// that the library would send the wrong ":scheme" metaheader to
+		// servers: it would send "http" instead of "https" because it is
+		// unaware that TLS is actually in use.
 		conn, err := (&net.Dialer{}).DialContext(ctx, network, address)
 		if err != nil {
 			writeResult(err)
-			return nil, err
 		}
-		if creds != nil {
-			conn, _, err = creds.ClientHandshake(ctx, address, conn)
-			if err != nil {
-				writeResult(err)
-				return nil, err
-			}
-		}
-		return conn, nil
+		return conn, err
 	}
 
 	// Even with grpc.FailOnNonTempDialError, this call will usually timeout in
 	// the face of TLS handshake errors. So we can't rely on grpc.WithBlock() to
 	// know when we're done. So we run it in a goroutine and then use result
-	// channel to either get the channel or fail-fast.
+	// channel to either get the connection or fail-fast.
 	go func() {
 		opts = append(opts,
 			grpc.WithBlock(),
 			grpc.FailOnNonTempDialError(true),
 			grpc.WithContextDialer(dialer),
-			grpc.WithInsecure(), // we are handling TLS, so tell grpc not to
 		)
+		if creds == nil {
+			opts = append(opts, grpc.WithInsecure())
+		} else {
+			opts = append(opts, grpc.WithTransportCredentials(creds))
+		}
 		conn, err := grpc.DialContext(ctx, address, opts...)
 		var res interface{}
 		if err != nil {
@@ -620,3 +664,18 @@ func BlockingDial(ctx context.Context, network, address string, creds credential
 		return nil, ctx.Err()
 	}
 }
+
+// errSignalingCreds is a wrapper around a TransportCredentials value, but
+// it will use the writeResult function to notify on error.
+type errSignalingCreds struct {
+	credentials.TransportCredentials
+	writeResult func(res interface{})
+}
+
+func (c *errSignalingCreds) ClientHandshake(ctx context.Context, addr string, rawConn net.Conn) (net.Conn, credentials.AuthInfo, error) {
+	conn, auth, err := c.TransportCredentials.ClientHandshake(ctx, addr, rawConn)
+	if err != nil {
+		c.writeResult(err)
+	}
+	return conn, auth, err
+}

grpcurl_test.go

@@ -300,6 +300,33 @@ func TestGetAllFiles(t *testing.T) {
 	}
 }
 
+func TestExpandHeaders(t *testing.T) {
+	inHeaders := []string{"key1: ${value}", "key2: bar", "key3: ${woo", "key4: woo}", "key5: ${TEST}",
+		"key6: ${TEST_VAR}", "${TEST}: ${TEST_VAR}", "key8: ${EMPTY}"}
+	os.Setenv("value", "value")
+	os.Setenv("TEST", "value5")
+	os.Setenv("TEST_VAR", "value6")
+	os.Setenv("EMPTY", "")
+	expectedHeaders := map[string]bool{"key1: value": true, "key2: bar": true, "key3: ${woo": true, "key4: woo}": true,
+		"key5: value5": true, "key6: value6": true, "value5: value6": true, "key8: ": true}
+
+	outHeaders, err := ExpandHeaders(inHeaders)
+	if err != nil {
+		t.Errorf("The ExpandHeaders function generated an unexpected error %s", err)
+	}
+	for _, expandedHeader := range outHeaders {
+		if _, ok := expectedHeaders[expandedHeader]; !ok {
+			t.Errorf("The ExpandHeaders function has returned an unexpected header. Received unexpected header %s", expandedHeader)
+		}
+	}
+
+	badHeaders := []string{"key: ${DNE}"}
+	_, err = ExpandHeaders(badHeaders)
+	if err == nil {
+		t.Errorf("The ExpandHeaders function should return an error for missing environment variables %q", badHeaders)
+	}
+}
+
 func fileNames(files []*desc.FileDescriptor) []string {
 	names := make([]string, len(files))
 	for i, f := range files {

tls_settings_test.go

@@ -109,24 +109,42 @@ func TestBrokenTLS_ClientPlainText(t *testing.T) {
 	}
 
 	// client connection (usually) succeeds since client is not waiting for TLS handshake
-	e, err := createTestServerAndClient(serverCreds, nil)
-	if err != nil {
-		if strings.Contains(err.Error(), "deadline exceeded") {
-			// It is possible that connection never becomes healthy:
+	// (we try several times, but if we never get a connection and the error message is
+	// a known/expected possibility, we'll just bail)
+	var e testEnv
+	failCount := 0
+	for {
+		e, err = createTestServerAndClient(serverCreds, nil)
+		if err == nil {
+			// success!
+			defer e.Close()
+			break
+		}
+
+		if strings.Contains(err.Error(), "deadline exceeded") ||
+			strings.Contains(err.Error(), "use of closed network connection") {
+			// It is possible that the connection never becomes healthy:
 			//   1) grpc connects successfully
 			//   2) grpc client tries to send HTTP/2 preface and settings frame
 			//   3) server, expecting handshake, closes the connection
 			//   4) in the client, the write fails, so the connection never
 			//      becomes ready
-			// More often than not, the connection becomes ready (presumably
-			// the write to the socket succeeds before the server closes the
-			// connection). But when it does not, it is possible to observe
-			// timeouts when setting up the connection.
-			return
+			// The client will attempt to reconnect on transient errors, so
+			// may eventually bump into the connect time limit. This used to
+			// result in a "deadline exceeded" error, but more recent versions
+			// of the grpc library report any underlying I/O error instead, so
+			// we also check for "use of closed network connection".
+			failCount++
+			if failCount > 5 {
+				return // bail...
+			}
+			// we'll try again
+
+		} else {
+			// some other error occurred, so we'll consider that a test failure
+			t.Fatalf("failed to setup server and client: %v", err)
 		}
-		t.Fatalf("failed to setup server and client: %v", err)
 	}
-	defer e.Close()
 
 	// but request fails because server closes connection upon seeing request
 	// bytes that are not a TLS handshake
@@ -285,7 +303,7 @@ func simpleTest(t *testing.T, cc *grpc.ClientConn) {
 	cl := grpc_testing.NewTestServiceClient(cc)
 	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
 	defer cancel()
-	_, err := cl.UnaryCall(ctx, &grpc_testing.SimpleRequest{}, grpc.FailFast(false))
+	_, err := cl.UnaryCall(ctx, &grpc_testing.SimpleRequest{}, grpc.WaitForReady(true))
 	if err != nil {
 		t.Errorf("simple RPC failed: %v", err)
 	}