feat: use gRPC metadata to pass additional info between client/server

core/api/client/jsonclient/client.go

@@ -5,10 +5,12 @@ import (
 	"fmt"
 	"strings"
 
+	"google.golang.org/grpc/metadata"
+
 	"berty.tech/core/api/client"
 )
 
-type unaryCallback func(*client.Client, context.Context, []byte) (interface{}, error)
+type unaryCallback func(*client.Client, context.Context, []byte) (interface{}, metadata.MD, metadata.MD, error)
 
 var unaryMap map[string]unaryCallback
 
@@ -19,16 +21,17 @@ func registerUnary(name string, endpoint unaryCallback) {
 	unaryMap[name] = endpoint
 }
 
-func CallUnary(ctx context.Context, c *client.Client, endpoint string, jsonInput []byte) (interface{}, error) {
+func CallUnary(ctx context.Context, c *client.Client, endpoint string, jsonInput []byte) (interface{}, metadata.MD, metadata.MD, error) {
 	if jsonInput == nil {
 		jsonInput = []byte("{}")
 	}
+
 	for name, handler := range unaryMap {
 		if strings.ToLower(name) == strings.ToLower(endpoint) {
 			return handler(c, ctx, jsonInput)
 		}
 	}
-	return nil, fmt.Errorf("unknown endpoint: %q", endpoint)
+	return nil, nil, nil, fmt.Errorf("unknown endpoint: %q", endpoint)
 }
 
 func Unaries() []string {

core/api/client/jsonclient/{{.File.Package}}.{{.Service.Name|lower}}.gen.go.tmpl

@@ -12,6 +12,7 @@ import (
         "{{regexReplaceAll "\"([^;]*).*\"" ($dependency.GoPkg|string) "${1}" }}"
         {{ end -}}
 	"berty.tech/core/api/client"
+        "google.golang.org/grpc"
 )
 
 {{- range $svc := .File.Service}}
@@ -30,7 +31,7 @@ import (
 
     {{ range $method := .Method}}
       {{if and (not .ClientStreaming) (not .ServerStreaming)}}
-      func {{$file.Package|splitList "."|last|title}}{{$method.Name}}(client *client.Client, ctx context.Context, jsonInput []byte) (interface{}, error) {
+      func {{$file.Package|splitList "."|last|title}}{{$method.Name}}(client *client.Client, ctx context.Context, jsonInput []byte) (interface{}, metadata.MD, metadata.MD, error) {
 	tracer := tracing.EnterFunc(ctx, string(jsonInput))
 	defer tracer.Finish()
 	ctx = tracer.Context()
@@ -40,7 +41,7 @@ import (
         {{ $in := $method.InputType | getMessageType $file }}
         var typedInput {{$in.GoType "."}}
         if err := json.Unmarshal(jsonInput, &typedInput); err != nil {
-              return nil, err
+              return nil, nil, nil, err
         }
 
 	var header, trailer metadata.MD
@@ -54,7 +55,7 @@ import (
 	tracer.SetAnyField("header", header)
 	tracer.SetAnyField("trailer", trailer)
 
-	return ret, err
+        return ret, header, trailer, err
       }
     {{- end}}
     {{if and (not .ClientStreaming) (.ServerStreaming)}}

core/api/p2p/event.go

@@ -70,7 +70,7 @@ func (e Event) ToJSON() string {
 
 func (e Event) CreateSpan(ctx context.Context) (opentracing.Span, context.Context) {
 	tracer := opentracing.GlobalTracer()
-	caller := tracing.GetCallerName("call", 1)
+	caller := tracing.GetCallerName(1)
 	topic := fmt.Sprintf("event::/%s/%s", e.Direction.String(), e.Kind.String())
 
 	// Retrieve span context inside the event if needed

core/cmd/berty/client.go

@@ -241,10 +241,19 @@ func clientUnary(opts *clientOptions) error {
 		input = []byte(opts.args[0])
 	}
 
-	ret, err := jsonclient.CallUnary(ctx, client, opts.endpoint, input)
+	ret, _, trailer, err := jsonclient.CallUnary(ctx, client, opts.endpoint, input)
 	if err != nil {
 		return errors.Wrap(err, "client error")
 	}
+	if len(trailer) > 0 {
+		fmt.Fprint(os.Stderr, "gRPC trailer:\n")
+		for key, values := range trailer {
+			fmt.Fprintf(os.Stderr, "  %s: (%d values)\n", key, len(values))
+			for _, value := range values {
+				fmt.Fprintf(os.Stderr, "    - %s\n", value)
+			}
+		}
+	}
 
 	jsonPrint(ret, opts)
 	return nil

core/go.mod

@@ -29,6 +29,7 @@ require (
 	github.com/gopherjs/gopherjs v0.0.0-20181004151105-1babbf986f6f // indirect
 	github.com/gopherjs/gopherwasm v1.0.1 // indirect
 	github.com/gorilla/websocket v1.4.0
+	github.com/gosimple/slug v1.4.2
 	github.com/grpc-ecosystem/go-grpc-middleware v1.0.1-0.20181112102510-3304cc886352
 	github.com/gxed/GoEndian v0.0.0-20160916112711-0f5c6873267e // indirect
 	github.com/gxed/eventfd v0.0.0-20160916113412-80a92cca79a8 // indirect
@@ -111,6 +112,7 @@ require (
 	github.com/nu7hatch/gouuid v0.0.0-20131221200532-179d4d0c4d8d // indirect
 	github.com/opentracing/opentracing-go v1.0.2
 	github.com/pkg/errors v0.8.0
+	github.com/rainycape/unidecode v0.0.0-20150907023854-cb7f23ec59be // indirect
 	github.com/rs/cors v1.6.0
 	github.com/sergi/go-diff v1.0.0 // indirect
 	github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d // indirect

core/go.sum

@@ -237,6 +237,8 @@ github.com/gorilla/sessions v1.1.2/go.mod h1:8KCfur6+4Mqcc6S0FEfKuN15Vl5MgXW92AE
 github.com/gorilla/sessions v1.1.3/go.mod h1:8KCfur6+4Mqcc6S0FEfKuN15Vl5MgXW92AE8ovaJD0w=
 github.com/gorilla/websocket v1.4.0 h1:WDFjx/TMzVgy9VdMMQi2K2Emtwi2QcUQsztZ/zLaH/Q=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
+github.com/gosimple/slug v1.4.2 h1:jDmprx3q/9Lfk4FkGZtvzDQ9Cj9eAmsjzeQGp24PeiQ=
+github.com/gosimple/slug v1.4.2/go.mod h1:ER78kgg1Mv0NQGlXiDe57DpCyfbNywXXZ9mIorhxAf0=
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.1-0.20181112102510-3304cc886352 h1:1GXyC+LmruB9uk340NwSS6UPwWNXM3xe6pbGpsXqAKc=
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.1-0.20181112102510-3304cc886352/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
 github.com/gxed/GoEndian v0.0.0-20160916112711-0f5c6873267e h1:eIhARPSF2zPr1hKxiL81XWQ392f5stEEcs38UzZVSWo=
@@ -473,6 +475,8 @@ github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rainycape/unidecode v0.0.0-20150907023854-cb7f23ec59be h1:ta7tUOvsPHVHGom5hKW5VXNc2xZIkfCKP8iaqOyYtUQ=
+github.com/rainycape/unidecode v0.0.0-20150907023854-cb7f23ec59be/go.mod h1:MIDFMn7db1kT65GmV94GzpX9Qdi7N/pQlwb+AN8wh+Q=
 github.com/rogpeppe/go-internal v1.0.0 h1:o4VLZ5jqHE+HahLT6drNtSGTrrUA3wPBmtpgqtdbClo=
 github.com/rogpeppe/go-internal v1.0.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rs/cors v1.6.0 h1:G9tHG9lebljV9mfp9SNPDL36nCDxmo3zTlAf1YgvzmI=

core/node/nodeapi_devtools.go

@@ -141,14 +141,14 @@ func (n *Node) GenerateFakeData(ctx context.Context, input *node.Void) (*node.Vo
 
 	/*
 		// enqueue fake incoming event
-		in := n.NewContactEvent(&entity.Contact{ID: "abcde"}, p2p.Kind_DevtoolsMapset)
-		if err := n.EnqueueClientEvent(in); err != nil {
+		in := n.NewContactEvent(ctx, &entity.Contact{ID: "abcde"}, p2p.Kind_DevtoolsMapset)
+		if err := n.EnqueueClientEvent(ctx, in); err != nil {
 			return nil, err
 		}
 
 		// enqueue fake outgoing event
-		out := n.NewContactEvent(&entity.Contact{ID: "abcde"}, p2p.Kind_DevtoolsMapset)
-		if err := n.EnqueueOutgoingEvent(out); err != nil {
+		out := n.NewContactEvent(ctx, &entity.Contact{ID: "abcde"}, p2p.Kind_DevtoolsMapset)
+		if err := n.EnqueueOutgoingEvent(ctx, out); err != nil {
 			return nil, err
 		}
 	*/

core/node/p2pclient.go

@@ -45,6 +45,8 @@ func (n *Node) EnqueueOutgoingEvent(ctx context.Context, event *p2p.Event) error
 	}
 	n.outgoingEvents <- event
 
+	tracer.SetMetadata("new-outgoing-event", event.ID)
+
 	return nil
 }
 

core/pkg/tracing/functracer.go

@@ -6,9 +6,12 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/gosimple/slug"
 	opentracing "github.com/opentracing/opentracing-go"
 	"github.com/opentracing/opentracing-go/log"
 	"go.uber.org/zap"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
 )
 
 // fixme: make debug configurable
@@ -18,11 +21,30 @@ type FuncTracer struct {
 	span      opentracing.Span
 	logger    *zap.Logger
 	startTime time.Time
+	caller    string
 }
 
 func (t *FuncTracer) Finish() {
 	t.span.Finish()
 	t.logger.Debug("func leave", zap.Duration("duration", time.Since(t.startTime)))
+	t.SetMetadata("duration", fmt.Sprintf("%s", time.Since(t.startTime)))
+}
+
+func (t *FuncTracer) SetMetadata(key string, value string) {
+	// check if is gRPC context
+	if grpc.ServerTransportStreamFromContext(t.ctx) == nil {
+		return
+	}
+
+	if err := grpc.SetTrailer(
+		t.ctx,
+		metadata.Pairs(
+			slug.Make(fmt.Sprintf("%s %s", t.caller, key)),
+			value,
+		),
+	); err != nil {
+		logger().Warn("failed to set grpc trailer on context", zap.Error(err))
+	}
 }
 
 func (t *FuncTracer) SetTag(key, value string) {
@@ -54,17 +76,18 @@ func (t *FuncTracer) Context() context.Context {
 func EnterFunc(ctx context.Context, args ...interface{}) *FuncTracer {
 	t := &FuncTracer{
 		startTime: time.Now(),
+		caller:    GetCallerName(1),
 	}
-
-	topic := GetCallerName("call", 1)
-	t.logger = zap.L().Named("vendor.tracing").With(zap.String("topic", topic))
+	callTopic := fmt.Sprintf("call::%s", t.caller)
+	t.logger = zap.L().Named("vendor.tracing").With(zap.String("topic", callTopic))
 
 	if ctx == nil {
 		ctx = context.Background()
 		t.logger.Warn("context is not set")
 	}
 
-	t.span, t.ctx = opentracing.StartSpanFromContext(ctx, topic)
+	t.span, t.ctx = opentracing.StartSpanFromContext(ctx, callTopic)
+	// t.SetMetadata("spanid", t.span...)
 
 	if len(args) > 0 {
 		for idx, arg := range args {

core/pkg/tracing/tracing.go

@@ -2,7 +2,6 @@ package tracing
 
 import (
 	"context"
-	"fmt"
 	"runtime"
 	"strings"
 
@@ -16,11 +15,11 @@ type Tracer interface {
 	SetAnyField(key string, value interface{})
 	Span() opentracing.Span
 	Context() context.Context
+	SetMetadata(key, value string)
 }
 
-func GetCallerName(prefix string, skip int) string {
+func GetCallerName(skip int) string {
 	function, _, _, _ := runtime.Caller(skip + 1)
 	funcName := runtime.FuncForPC(function).Name()
-	caller := strings.Replace(funcName, "berty.tech/core/", "./", 1)
-	return fmt.Sprintf("%s::%s()", prefix, caller)
+	return strings.Replace(funcName, "berty.tech/core/", "./", 1)
 }