Add some tracing to service

server/middleware.go

@@ -1,10 +1,12 @@
 package server
 
 import (
+	"fmt"
 	"net/http"
 	"time"
 
 	"github.com/go-chi/chi/v5/middleware"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 )
 
 func (s *UserServer) MiddlewareLogging(next http.Handler) http.Handler {
@@ -24,3 +26,11 @@ func (s *UserServer) MiddlewareLogging(next http.Handler) http.Handler {
 	}
 	return http.HandlerFunc(fn)
 }
+
+func (s *UserServer) MiddlewareTracing(next http.Handler) http.Handler {
+	fn := func(w http.ResponseWriter, r *http.Request) {
+		h := otelhttp.NewHandler(next, fmt.Sprintf("%s %s", r.Method, r.URL.Path))
+		h.ServeHTTP(w, r)
+	}
+	return http.HandlerFunc(fn)
+}

server/server.go

@@ -2,11 +2,13 @@ package server
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"log/slog"
 	"net/http"
 	"os"
+	"time"
 
 	"git.t-juice.club/microfilm/auth"
 	"git.t-juice.club/microfilm/auth/authmw"
@@ -15,6 +17,12 @@ import (
 	"github.com/go-chi/chi/v5"
 	"github.com/google/uuid"
 	"github.com/nats-io/nats.go"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
 )
 
 type UserServer struct {
@@ -28,6 +36,13 @@ type UserServer struct {
 func NewServer(config *Config) (*UserServer, error) {
 	r := chi.NewRouter()
 	srv := &UserServer{}
+
+	tp, err := tracerProvider("jaeger:4318")
+	if err != nil {
+		return nil, err
+	}
+	otel.SetTracerProvider(tp)
+
 	srv.config = config
 
 	srv.Logger = slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
@@ -35,6 +50,7 @@ func NewServer(config *Config) (*UserServer, error) {
 	}))
 
 	r.Use(srv.MiddlewareLogging)
+	r.Use(srv.MiddlewareTracing)
 
 	verifyAdmin := authmw.VerifyToken("http://mf-auth:8082", []string{auth.RoleAdmin})
 
@@ -71,6 +87,26 @@ func NewServer(config *Config) (*UserServer, error) {
 	return srv, nil
 }
 
+func tracerProvider(url string) (*sdktrace.TracerProvider, error) {
+	exp, err := otlptracehttp.New(context.Background(), otlptracehttp.WithEndpoint(url), otlptracehttp.WithInsecure())
+	if err != nil {
+		return nil, err
+	}
+
+	res := resource.NewWithAttributes(semconv.SchemaURL,
+		semconv.ServiceName("mf-users"),
+		semconv.ServiceVersion(users.Version),
+	)
+	tp := sdktrace.NewTracerProvider(
+		sdktrace.WithBatcher(exp, sdktrace.WithBatchTimeout(time.Second)),
+		sdktrace.WithResource(res),
+	)
+	otel.SetTracerProvider(tp)
+	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
+
+	return tp, nil
+}
+
 func InfoHandler(w http.ResponseWriter, r *http.Request) {
 	enc := json.NewEncoder(w)