Add jaeger tracing and properly set grpc interceptors

Signed-off-by: Alexandre Beslic <abeslic@abronan.com>

README.md

@@ -54,48 +54,48 @@ GLOBAL OPTIONS:
 - Create a new Todo:
 
 ```bash
-$ curl -X POST -H "Content-Type: application/json" -d '{"title":"Test","description":"Test"}' "http://localhost:8080/v1/todo"
+curl -X POST -H "Content-Type: application/json" -d '{"title":"Test","description":"Test"}' "http://localhost:8080/v1/todo"
 {"id":"34d63bd4-56b3-4795-80d4-86e5db6fa0b5"}
 ```
 
 - Get an existing Todo:
 
 ```bash
-$ curl -X GET "http://localhost:8080/v1/todo/34d63bd4-56b3-4795-80d4-86e5db6fa0b5"
+curl -X GET "http://localhost:8080/v1/todo/34d63bd4-56b3-4795-80d4-86e5db6fa0b5"
 {"item":{"id":"34d63bd4-56b3-4795-80d4-86e5db6fa0b5","title":"Test","description":"Test","created_at":"2018-03-30T20:13:25.291887Z"}}
 ```
 
 - List Todos (example with limit and non completed items in query parameters):
 
 ```bash
-$ curl -X GET "http://localhost:8080/v1/todo?limit=10&not_completed=true"
+curl -X GET "http://localhost:8080/v1/todo?limit=10&not_completed=true"
 ```
 
 - Update a Todo:
 
 ```bash
-$ curl -X PUT -H "Content-Type: application/json" -d '{"id": "34d63bd4-56b3-4795-80d4-86e5db6fa0b5", "title":"TestBis", "description":"TestBis", "completed": true}' "http://localhost:8080/v1/todo"
+curl -X PUT -H "Content-Type: application/json" -d '{"id": "34d63bd4-56b3-4795-80d4-86e5db6fa0b5", "title":"TestBis", "description":"TestBis", "completed": true}' "http://localhost:8080/v1/todo"
 {}
 ```
 
 - Delete a Todo:
 
 ```bash
-$ curl -X DELETE "http://localhost:8080/v1/todo/34d63bd4-56b3-4795-80d4-86e5db6fa0b5"
+curl -X DELETE "http://localhost:8080/v1/todo/34d63bd4-56b3-4795-80d4-86e5db6fa0b5"
 {}
 ```
 
 - Bulk Insert Todos:
 
 ```bash
-$ curl -X POST -H "Content-Type: application/json" -d '{"items": [{"title":"Todo_1","description":"Todo_1"},{"title":"Todo_2","description":"Todo_2"}]}' "http://localhost:8080/v1/todo/bulk"
+curl -X POST -H "Content-Type: application/json" -d '{"items": [{"title":"Todo_1","description":"Todo_1"},{"title":"Todo_2","description":"Todo_2"}]}' "http://localhost:8080/v1/todo/bulk"
 {"ids":["e8924469-8847-4840-ae16-21be734173f4","0db11e34-4707-4a5d-92fe-f4952213d940"]}
 ```
 
 - Bulk Update Todos:
 
 ```bash
-$ curl -X PUT -H "Content-Type: application/json" -d '{"items": [{"id":"e94a6d0b-953b-4dad-aecb-318f183db4c7","title":"Todo_1","description":"Todo_1","completed":true},{"id":"d53daa2c-e6af-45ba-b192-3e1dc443b165","title":"Todo_2","description":"Todo_2","completed":true}]}' "http://localhost:8080/v1/todo/bulk"
+curl -X PUT -H "Content-Type: application/json" -d '{"items": [{"id":"e94a6d0b-953b-4dad-aecb-318f183db4c7","title":"Todo_1","description":"Todo_1","completed":true},{"id":"d53daa2c-e6af-45ba-b192-3e1dc443b165","title":"Todo_2","description":"Todo_2","completed":true}]}' "http://localhost:8080/v1/todo/bulk"
 {}
 ```
 
@@ -109,7 +109,7 @@ $ curl -X PUT -H "Content-Type: application/json" -d '{"items": [{"id":"e94a6d0b
 
 ## Author
 
-**Alexandre Beslic**
+Alexandre Beslic
 
 - [abronan.com](https://abronan.com)
 - [@abronan](https://twitter.com/abronan)

flags.go

@@ -5,21 +5,24 @@ import (
 )
 
 var commonFlags = []cli.Flag{
-	// Server
 	cli.StringFlag{
 		Name:   "bind-http",
 		Usage:  "bind address for HTTP",
 		EnvVar: "BIND_HTTP",
-		Value:  "localhost:8080",
+		Value:  ":8080",
 	},
 	cli.StringFlag{
 		Name:   "bind-grpc",
 		Usage:  "bind address for gRPC",
 		EnvVar: "BIND_GRPC",
-		Value:  "localhost:2338",
+		Value:  ":2338",
+	},
+	cli.StringFlag{
+		Name:   "bind-prometheus-http",
+		Usage:  "bind prometheus address for HTTP",
+		EnvVar: "BIND_PROMETHEUS_HTTP",
+		Value:  ":8081",
 	},
-
-	// PostgresQL
 	cli.StringFlag{
 		Name:   "db-name",
 		Usage:  "database name",
@@ -49,4 +52,28 @@ var commonFlags = []cli.Flag{
 		EnvVar: "DB_PORT",
 		Value:  5432,
 	},
+	cli.StringFlag{
+		Name:   "jaeger-host",
+		Usage:  "Jaeger hostname",
+		EnvVar: "JAEGER_HOST",
+		Value:  "127.0.0.1",
+	},
+	cli.IntFlag{
+		Name:   "jaeger-port",
+		Usage:  "Jaeger port",
+		EnvVar: "JAEGER_PORT",
+		Value:  5775,
+	},
+	cli.Float64Flag{
+		Name:   "jaeger-sampler",
+		Usage:  "Jaeger sampler",
+		EnvVar: "JAEGER_SAMPLER",
+		Value:  0.05,
+	},
+	cli.StringFlag{
+		Name:   "jaeger-tags",
+		Usage:  "Jaeger tags",
+		EnvVar: "JAEGER_TAGS",
+		Value:  "directory",
+	},
 }

main.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"context"
+	"fmt"
+	"io"
 	"net"
 	"net/http"
 	"os"
@@ -18,12 +20,22 @@ import (
 	"github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing"
 	"github.com/grpc-ecosystem/go-grpc-prometheus"
 	"github.com/grpc-ecosystem/grpc-gateway/runtime"
+	opentracing "github.com/opentracing/opentracing-go"
+	"github.com/uber/jaeger-client-go/config"
+	"github.com/uber/jaeger-client-go/rpcmetrics"
+	"github.com/uber/jaeger-lib/metrics"
+	prometheus_metrics "github.com/uber/jaeger-lib/metrics/prometheus"
 
 	log "github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 	"google.golang.org/grpc"
 )
 
+var (
+	metricsFactory metrics.Factory
+	tracer         opentracing.Tracer
+)
+
 func main() {
 	app := cli.NewApp()
 	app.Name = path.Base(os.Args[0])
@@ -43,27 +55,46 @@ func start(c *cli.Context) {
 		log.Fatalf("failed to listen: %v", c.String("bind-grpc"))
 	}
 
+	// Logrus
 	logrusEntry := log.NewEntry(log.New())
 	grpc_logrus.ReplaceGrpcLogger(logrusEntry)
 	log.SetLevel(log.InfoLevel)
 
+	// Prometheus monitoring
+	metricsFactory = prometheus_metrics.New()
+
+	// Jaeger tracing
+	tracer, closer, err := newTracing(
+		"todo",
+		c.String("jaeger-host")+":"+c.String("jaeger-port"),
+		metricsFactory.Namespace("todo", nil),
+		logrusEntry,
+		c.Float64("jaeger-sampler"),
+	)
+	if err != nil {
+		panic(err.Error())
+	}
+	defer closer.Close()
+
+	// Set GRPC Interceptors
 	server := grpc.NewServer(
 		grpc.StreamInterceptor(grpc_middleware.ChainStreamServer(
-			grpc_ctxtags.StreamServerInterceptor(),
-			grpc_opentracing.StreamServerInterceptor(),
+			grpc_ctxtags.StreamServerInterceptor(grpc_ctxtags.WithFieldExtractor(grpc_ctxtags.CodeGenRequestFieldExtractor)),
+			grpc_opentracing.StreamServerInterceptor(grpc_opentracing.WithTracer(tracer)),
 			grpc_prometheus.StreamServerInterceptor,
 			grpc_logrus.StreamServerInterceptor(logrusEntry),
 			grpc_recovery.StreamServerInterceptor(),
 		)),
 		grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(
-			grpc_ctxtags.UnaryServerInterceptor(),
-			grpc_opentracing.UnaryServerInterceptor(),
+			grpc_ctxtags.UnaryServerInterceptor(grpc_ctxtags.WithFieldExtractor(grpc_ctxtags.CodeGenRequestFieldExtractor)),
+			grpc_opentracing.UnaryServerInterceptor(grpc_opentracing.WithTracer(tracer)),
 			grpc_prometheus.UnaryServerInterceptor,
 			grpc_logrus.UnaryServerInterceptor(logrusEntry),
 			grpc_recovery.UnaryServerInterceptor(),
 		)),
 	)
 
+	// Connect to PostgresQL
 	db := pg.Connect(&pg.Options{
 		User:     c.String("db-user"),
 		Password: c.String("db-password"),
@@ -77,6 +108,7 @@ func start(c *cli.Context) {
 	// Create Table from Todo struct generated by gRPC
 	db.CreateTable(&api.Todo{}, nil)
 
+	// Register Todo service, prometheus and HTTP service handler
 	api.RegisterTodoServiceServer(server, &todo.Service{DB: db})
 	grpc_prometheus.Register(server)
 	mux := runtime.NewServeMux()
@@ -94,3 +126,38 @@ func start(c *cli.Context) {
 	}
 	http.ListenAndServe(c.String("bind-http"), mux)
 }
+
+func newTracing(service, jaegerHost string, metrics metrics.Factory, logger *log.Entry, sampler float64) (tracer opentracing.Tracer, closer io.Closer, err error) {
+	cfg := config.Configuration{
+		Sampler: &config.SamplerConfig{
+			Type:  "const",
+			Param: sampler,
+		},
+		Reporter: &config.ReporterConfig{
+			LogSpans:            false,
+			BufferFlushInterval: 1 * time.Second,
+			LocalAgentHostPort:  jaegerHost,
+		},
+	}
+	tracer, closer, err = cfg.New(
+		service,
+		config.Logger(jaegerLoggerAdapter{logger}),
+		config.Observer(rpcmetrics.NewObserver(metricsFactory, rpcmetrics.DefaultNameNormalizer)),
+	)
+	if err != nil {
+		logger.Fatalf("cannot initialize Jaeger Tracer %s", err)
+	}
+	return
+}
+
+type jaegerLoggerAdapter struct {
+	logger *log.Entry
+}
+
+func (l jaegerLoggerAdapter) Error(msg string) {
+	l.logger.Error(msg)
+}
+
+func (l jaegerLoggerAdapter) Infof(msg string, args ...interface{}) {
+	l.logger.Info(fmt.Sprintf(msg, args...))
+}