robin/dttmr-api
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Added OpenTelemetry and use structured logging

Browse Source
This commit is contained in:
Robin Dittmar
2026-07-07 16:18:14 +02:00
parent 860563b47f
commit 0dec97a865
10 changed files with 191 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Dockerfile
+1 -2
View File
@@ -1,8 +1,7 @@
FROM golang:1.26 AS build
WORKDIR /app
#COPY go.mod go.sum ./
COPY go.mod ./
COPY go.mod go.sum ./
RUN go mod download
cmd/api-server/main.go
+46 -7
View File
@@ -3,7 +3,7 @@ package main
import (
"context"
"errors"
"log"
"log/slog"
"net/http"
"os"
"os/signal"
@@ -11,9 +11,44 @@ import (
"time"
"github.com/robindittmar/dttmr-api/internal/api/router"
"github.com/robindittmar/dttmr-api/internal/telemetry"
)
func main() {
serviceName := "dttmr-api"
serviceVersion := "0.1.0"
if err := run(serviceName, serviceVersion); err != nil {
slog.Error("Service crashed", slog.Any("error", err))
os.Exit(1)
}
}
func run(serviceName string, serviceVersion string) error {
baseHandler := slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
Level: slog.LevelInfo,
})
traceHandler := &telemetry.TraceHandler{Handler: baseHandler}
logger := slog.New(traceHandler)
slog.SetDefault(logger)
slog.Info("Starting service", slog.String("service", serviceName), slog.String("version", serviceVersion))
shutdownTelemetry, err := telemetry.Init(context.Background(), serviceName, serviceVersion)
if err != nil {
slog.Error("Failed to initialize telemetry", err)
return err
}
defer func() {
shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
if err := shutdownTelemetry(shutdownCtx); err != nil {
slog.Error("Failed to shutdown telemetry", err)
}
}()
cfg := router.Config{}
mux := router.NewMux(cfg)
@@ -26,22 +61,26 @@ func main() {
}
go func() {
log.Printf("Listening on %s\n", srv.Addr)
slog.Info("Starting http server", "addr", srv.Addr)
if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
log.Fatalf("Failed to start server: %v", err)
slog.Error("Failed to start http server", err)
os.Exit(1)
}
}()
quit := make(chan os.Signal, 1)
signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
<-quit
log.Println("Shutting down server...")
sig := <-quit
slog.Info("Shutting down server...", slog.String("signal", sig.String()))
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
if err := srv.Shutdown(ctx); err != nil {
log.Fatalf("Server forced to shutdown: %v", err)
slog.Error("Server forced to shutdown", slog.Any("error", err))
return err
}
log.Println("Server shutdown successful!")
slog.Info("Service shutdown successful!")
return nil
}
go.mod
+29
View File
@@ -1,3 +1,32 @@
module github.com/robindittmar/dttmr-api
go 1.26
require (
go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.69.0
go.opentelemetry.io/otel v1.44.0
go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.44.0
go.opentelemetry.io/otel/sdk v1.44.0
)
require (
github.com/cenkalti/backoff/v5 v5.0.3 // indirect
github.com/cespare/xxhash/v2 v2.3.0 // indirect
github.com/felixge/httpsnoop v1.0.4 // indirect
github.com/go-logr/logr v1.4.3 // indirect
github.com/go-logr/stdr v1.2.2 // indirect
github.com/google/uuid v1.6.0 // indirect
github.com/grpc-ecosystem/grpc-gateway/v2 v2.29.0 // indirect
go.opentelemetry.io/auto/sdk v1.2.1 // indirect
go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.44.0 // indirect
go.opentelemetry.io/otel/metric v1.44.0 // indirect
go.opentelemetry.io/otel/trace v1.44.0 // indirect
go.opentelemetry.io/proto/otlp v1.10.0 // indirect
golang.org/x/net v0.55.0 // indirect
golang.org/x/sys v0.45.0 // indirect
golang.org/x/text v0.37.0 // indirect
google.golang.org/genproto/googleapis/api v0.0.0-20260526163538-3dc84a4a5aaa // indirect
google.golang.org/genproto/googleapis/rpc v0.0.0-20260526163538-3dc84a4a5aaa // indirect
google.golang.org/grpc v1.81.1 // indirect
google.golang.org/protobuf v1.36.11 // indirect
)
internal/api/handler/default.go
+13 -11
View File
@@ -1,7 +1,7 @@
package handler
import (
"log"
"log/slog"
"net/http"
"github.com/robindittmar/dttmr-api/internal/api/response"
@@ -18,15 +18,17 @@ type apiResponse struct {
}
func DefaultHandler(w http.ResponseWriter, r *http.Request) {
var resp apiResponse
ctx := r.Context()
resp.Method = r.Method
resp.Url = r.URL.String()
resp.Proto = r.Proto
resp.Header = make(map[string]string)
resp.Host = r.Host
resp.RemoteAddr = r.RemoteAddr
resp.Form = make(map[string]string)
resp := apiResponse{
Method: r.Method,
Url: r.URL.String(),
Proto: r.Proto,
Header: make(map[string]string),
Host: r.Host,
RemoteAddr: r.RemoteAddr,
Form: make(map[string]string),
}
for k, v := range r.Header {
resp.Header[k] = v[0]
@@ -37,8 +39,8 @@ func DefaultHandler(w http.ResponseWriter, r *http.Request) {
resp.Form[k] = v[0]
}
} else {
log.Println(err)
slog.ErrorContext(ctx, "Error parsing form", slog.Any("error", err))
}
response.JSON(w, http.StatusOK, resp)
response.JSON(ctx, w, http.StatusOK, resp)
}
internal/api/handler/health.go
+3 -2
View File
@@ -11,9 +11,10 @@ type healthResponse struct {
}
func HealthHandler(w http.ResponseWriter, r *http.Request) {
_ = r
ctx := r.Context()
resp := healthResponse{
Status: "ok",
}
response.JSON(w, http.StatusOK, resp)
response.JSON(ctx, w, http.StatusOK, resp)
}
internal/api/middleware/telemetry.go
+3 -2
View File
@@ -2,9 +2,10 @@ package middleware
import (
"net/http"
"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
)
func WithTelemetry(next http.Handler) http.Handler {
//return otelhttp.NewHandler(next, "dttmr-api")
return next
return otelhttp.NewHandler(next, "dttmr-api")
}
internal/api/response/json.go
+7 -6
View File
@@ -1,19 +1,20 @@
package response
import (
"context"
"encoding/json"
"log"
"log/slog"
"net/http"
)
func JSON(w http.ResponseWriter, status int, data any) {
func JSON(ctx context.Context, w http.ResponseWriter, status int, data any) {
payload, err := json.Marshal(data)
if err != nil {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusInternalServerError)
_, err := w.Write([]byte(`{"error": "internal server error: failed to marshal response"}`))
if err != nil {
log.Println(err)
slog.ErrorContext(ctx, "Failed to write JSON", slog.Any("error", err))
return
}
return
@@ -23,11 +24,11 @@ func JSON(w http.ResponseWriter, status int, data any) {
w.WriteHeader(status)
_, err = w.Write(payload)
if err != nil {
log.Println(err)
slog.ErrorContext(ctx, "Failed to write response", slog.Any("error", err))
return
}
}
func Error(w http.ResponseWriter, status int, message string) {
JSON(w, status, map[string]string{"error": message})
func Error(ctx context.Context, w http.ResponseWriter, status int, message string) {
JSON(ctx, w, status, map[string]string{"error": message})
}
internal/telemetry/.gitkeep
View File
internal/telemetry/logger.go
+32
View File
@@ -0,0 +1,32 @@
package telemetry
import (
"context"
"log/slog"
"go.opentelemetry.io/otel/trace"
)
type TraceHandler struct {
slog.Handler
}
func (h *TraceHandler) Handle(ctx context.Context, r slog.Record) error {
spanCtx := trace.SpanContextFromContext(ctx)
if spanCtx.HasTraceID() {
r.AddAttrs(
slog.String("trace_id", spanCtx.TraceID().String()),
slog.String("span_id", spanCtx.SpanID().String()),
)
}
return h.Handler.Handle(ctx, r)
}
func (h *TraceHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
return &TraceHandler{Handler: h.Handler.WithAttrs(attrs)}
}
func (h *TraceHandler) WithGroup(name string) slog.Handler {
return &TraceHandler{Handler: h.Handler.WithGroup(name)}
}
internal/telemetry/otel.go
+57
View File
@@ -0,0 +1,57 @@
package telemetry
import (
"context"
"errors"
"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
"go.opentelemetry.io/otel/propagation"
"go.opentelemetry.io/otel/sdk/resource"
sdktrace "go.opentelemetry.io/otel/sdk/trace"
semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
)
func Init(ctx context.Context, serviceName string, version string) (func(context.Context) error, error) {
var shutdownFns []func(context.Context) error
shutdown := func(ctx context.Context) error {
var err error
for _, fn := range shutdownFns {
err = errors.Join(err, fn(ctx))
}
shutdownFns = nil
return err
}
res, err := resource.New(ctx,
resource.WithAttributes(
semconv.ServiceName(serviceName),
semconv.ServiceVersion(version),
),
)
if err != nil {
return shutdown, err
}
otel.SetTextMapPropagator(
propagation.NewCompositeTextMapPropagator(
propagation.TraceContext{},
propagation.Baggage{},
),
)
traceExporter, err := otlptracegrpc.New(ctx)
if err != nil {
return shutdown, err
}
tracerProvider := sdktrace.NewTracerProvider(
sdktrace.WithBatcher(traceExporter),
sdktrace.WithResource(res),
)
otel.SetTracerProvider(tracerProvider)
shutdownFns = append(shutdownFns, tracerProvider.Shutdown)
return shutdown, nil
}