OpenTelemetry対応をする

.github/workflows/ci.yml

@@ -11,16 +11,16 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go_version: [ 1.21 ]
+        go_version: [ 1.22 ]
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Install Dependencies
       run: |
         sudo apt update
         sudo apt install -y webp
     - name: Setup Go
-      uses: actions/setup-go@v3
+      uses: actions/setup-go@v5
       with:
         go-version: ${{ matrix.go_version }}
     - name: Test

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.21-bullseye AS build
+FROM golang:1.22-bullseye AS build
 
 ARG OYAKI_VERSION
 

README.md

@@ -20,3 +20,7 @@ Environment variables bellow are available.
 - `OYAKI_ORIGIN_HOST`: Your origin host. Example: `example.com` (required)
 - `OYAKI_ORIGIN_SCHEME`: Scheme to request to your origin. Default: `https`
 - `OYAKI_QUALITY`: Image quality. Default: `90`
+
+### Use OpenTelemetry
+
+- `OTEL_EXPORTER_OTLP_ENDPOINT`: OpenTelemetry collector endpoint. Example: `localhost:4317`

convert.go

@@ -2,13 +2,17 @@ package main
 
 import (
 	"bytes"
+	"context"
 	"image/jpeg"
 	"io"
 
 	"github.com/disintegration/imaging"
 )
 
-func convert(src io.Reader, q int) (*bytes.Buffer, error) {
+func convert(ctx context.Context, src io.Reader, q int) (*bytes.Buffer, error) {
+	ctx, span := tracer.Start(ctx, "convert")
+	defer span.End()
+
 	img, err := imaging.Decode(src, imaging.AutoOrientation(true))
 	if err != nil {
 		return nil, err

go.mod

@@ -2,6 +2,29 @@ module github.com/pepabo/oyaki
 
 go 1.19
 
-require github.com/disintegration/imaging v1.6.2
+require (
+	github.com/disintegration/imaging v1.6.2
+	go.opentelemetry.io/otel v1.24.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.24.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.24.0
+	go.opentelemetry.io/otel/sdk v1.24.0
+	go.opentelemetry.io/otel/trace v1.24.0
+	google.golang.org/grpc v1.62.1
+)
 
-require golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8 // indirect
+require (
+	github.com/cenkalti/backoff/v4 v4.2.1 // indirect
+	github.com/go-logr/logr v1.4.1 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.0 // indirect
+	go.opentelemetry.io/otel/metric v1.24.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.1.0 // indirect
+	golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8 // indirect
+	golang.org/x/net v0.20.0 // indirect
+	golang.org/x/sys v0.17.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20240123012728-ef4313101c80 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240123012728-ef4313101c80 // indirect
+	google.golang.org/protobuf v1.32.0 // indirect
+)

go.sum

@@ -1,5 +1,56 @@
+github.com/cenkalti/backoff/v4 v4.2.1 h1:y4OZtCnogmCPw98Zjyt5a6+QwPLGkiQsYW5oUqylYbM=
+github.com/cenkalti/backoff/v4 v4.2.1/go.mod h1:Y3VNntkOUPxTVeUxJ/G5vcM//AlwfmyYozVcomhLiZE=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/disintegration/imaging v1.6.2 h1:w1LecBlG2Lnp8B3jk5zSuNqd7b4DXhcjwek1ei82L+c=
 github.com/disintegration/imaging v1.6.2/go.mod h1:44/5580QXChDfwIclfc/PCwrr44amcmDAg8hxG0Ewe4=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.4.1 h1:pKouT5E8xu9zeFC39JXRDukb6JFQPXM5p5I91188VAQ=
+github.com/go-logr/logr v1.4.1/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
+github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
+github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.0 h1:Wqo399gCIufwto+VfwCSvsnfGpF/w5E9CNxSwbpD6No=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.0/go.mod h1:qmOFXW2epJhM0qSnUUYpldc7gVz2KMQwJ/QYCDIa7XU=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+go.opentelemetry.io/otel v1.24.0 h1:0LAOdjNmQeSTzGBzduGe/rU4tZhMwL5rWgtp9Ku5Jfo=
+go.opentelemetry.io/otel v1.24.0/go.mod h1:W7b9Ozg4nkF5tWI5zsXkaKKDjdVjpD4oAt9Qi/MArHo=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.24.0 h1:t6wl9SPayj+c7lEIFgm4ooDBZVb01IhLB4InpomhRw8=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.24.0/go.mod h1:iSDOcsnSA5INXzZtwaBPrKp/lWu/V14Dd+llD0oI2EA=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.24.0 h1:Mw5xcxMwlqoJd97vwPxA8isEaIoxsta9/Q51+TTJLGE=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.24.0/go.mod h1:CQNu9bj7o7mC6U7+CA/schKEYakYXWr79ucDHTMGhCM=
+go.opentelemetry.io/otel/metric v1.24.0 h1:6EhoGWWK28x1fbpA4tYTOWBkPefTDQnb8WSGXlc88kI=
+go.opentelemetry.io/otel/metric v1.24.0/go.mod h1:VYhLe1rFfxuTXLgj4CBiyz+9WYBA8pNGJgDcSFRKBco=
+go.opentelemetry.io/otel/sdk v1.24.0 h1:YMPPDNymmQN3ZgczicBY3B6sf9n62Dlj9pWD3ucgoDw=
+go.opentelemetry.io/otel/sdk v1.24.0/go.mod h1:KVrIYw6tEubO9E96HQpcmpTKDVn9gdv35HoYiQWGDFg=
+go.opentelemetry.io/otel/trace v1.24.0 h1:CsKnnL4dUAr/0llH9FKuc698G04IrpWV0MQA/Y1YELI=
+go.opentelemetry.io/otel/trace v1.24.0/go.mod h1:HPc3Xr/cOApsBI154IU0OI0HJexz+aw5uPdbs3UCjNU=
+go.opentelemetry.io/proto/otlp v1.1.0 h1:2Di21piLrCqJ3U3eXGCTPHE9R8Nh+0uglSnOyxikMeI=
+go.opentelemetry.io/proto/otlp v1.1.0/go.mod h1:GpBHCBWiqvVLDqmHZsoMM3C5ySeKTC7ej/RNTae6MdY=
+go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8 h1:hVwzHzIUGRjiF7EcUjqNxk3NCfkPxbDKRdnNE1Rpg0U=
 golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
+golang.org/x/net v0.20.0 h1:aCL9BSgETF1k+blQaYUBx9hJ9LOGP3gAVemcZlf1Kpo=
+golang.org/x/net v0.20.0/go.mod h1:z8BVo6PvndSri0LbOE3hAn0apkU+1YvI6E70E9jsnvY=
+golang.org/x/sys v0.17.0 h1:25cE3gD+tdBA7lp7QfhuV+rJiE9YXTcS3VG1SqssI/Y=
+golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
+golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/genproto v0.0.0-20240123012728-ef4313101c80 h1:KAeGQVN3M9nD0/bQXnr/ClcEMJ968gUXJQ9pwfSynuQ=
+google.golang.org/genproto/googleapis/api v0.0.0-20240123012728-ef4313101c80 h1:Lj5rbfG876hIAYFjqiJnPHfhXbv+nzTWfm04Fg/XSVU=
+google.golang.org/genproto/googleapis/api v0.0.0-20240123012728-ef4313101c80/go.mod h1:4jWUdICTdgc3Ibxmr8nAJiiLHwQBY0UI0XZcEMaFKaA=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20240123012728-ef4313101c80 h1:AjyfHzEPEFp/NpvfN5g+KDla3EMojjhRVZc1i7cj+oM=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20240123012728-ef4313101c80/go.mod h1:PAREbraiVEVGVdTZsVWjSbbTtSyGbAgIIvni8a8CD5s=
+google.golang.org/grpc v1.62.1 h1:B4n+nfKzOICUXMgyrNd19h/I9oH0L1pizfk1d4zSgTk=
+google.golang.org/grpc v1.62.1/go.mod h1:IWTG0VlJLCh1SkC58F7np9ka9mx/WNkjl4PGJaiq+QE=
+google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
+google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
+google.golang.org/protobuf v1.32.0 h1:pPC6BG5ex8PDFnkbrGU3EixyhKcQ2aDuBS36lqK/C7I=
+google.golang.org/protobuf v1.32.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"context"
 	"errors"
 	"flag"
 	"fmt"
@@ -28,6 +29,12 @@ func main() {
 	flag.BoolVar(&ver, "version", false, "show version")
 	flag.Parse()
 
+	ctx := context.Background()
+	ctx, cancel := context.WithTimeout(ctx, 3*time.Second)
+	shutdown := initProvider(ctx)
+	defer cancel()
+	defer shutdown()
+
 	if ver {
 		fmt.Printf("oyaki %s\n", getVersion())
 		return
@@ -46,10 +53,17 @@ func main() {
 
 	log.Printf("starting oyaki %s\n", getVersion())
 	http.HandleFunc("/", proxy)
-	http.ListenAndServe(":8080", nil)
+
+	if err := http.ListenAndServe(":8080", nil); err != nil {
+		log.Fatal(err)
+	}
 }
 
 func proxy(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+	ctx, span := tracer.Start(ctx, "httpRequest")
+	defer span.End()
+
 	path := r.URL.RequestURI()
 	if path == "/" {
 		fmt.Fprintln(w, "Oyaki lives!")
@@ -82,7 +96,7 @@ func proxy(w http.ResponseWriter, r *http.Request) {
 	var orgRes *http.Response
 	pathExt := filepath.Ext(req.URL.Path)
 	if pathExt == ".webp" {
-		orgRes, err = doWebp(req)
+		orgRes, err = doWebp(ctx, req)
 	} else {
 		orgRes, err = client.Do(req)
 	}
@@ -147,15 +161,15 @@ func proxy(w http.ResponseWriter, r *http.Request) {
 
 		body := io.NopCloser(bytes.NewBuffer(resBytes))
 		defer body.Close()
-		buf, err = convWebp(body, []string{})
+		buf, err = convWebp(ctx, body, []string{})
 		if err == nil {
 			defer buf.Reset()
 			w.Header().Set("Content-Type", "image/webp")
 		} else {
 			// if err, normally convertion will be proceeded
 			body = io.NopCloser(bytes.NewBuffer(resBytes))
 			defer body.Close()
-			buf, err = convert(body, quality)
+			buf, err = convert(ctx, body, quality)
 			if err != nil {
 				http.Error(w, "Image convert failed", http.StatusInternalServerError)
 				log.Printf("Image convert failed. %v\n", err)
@@ -165,7 +179,7 @@ func proxy(w http.ResponseWriter, r *http.Request) {
 			w.Header().Set("Content-Type", "image/jpeg")
 		}
 	} else {
-		buf, err = convert(orgRes.Body, quality)
+		buf, err = convert(ctx, orgRes.Body, quality)
 		if err != nil {
 			http.Error(w, "Image convert failed", http.StatusInternalServerError)
 			log.Printf("Image convert failed. %v\n", err)

trace.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"context"
+	"log"
+	"os"
+	"strconv"
+	"time"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
+	"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/v1.4.0"
+	"google.golang.org/grpc"
+)
+
+var tracer = otel.Tracer("oyaki")
+
+func initProvider(ctx context.Context) func() {
+	res, err := resource.New(ctx,
+		resource.WithFromEnv(),
+		resource.WithProcess(),
+		resource.WithTelemetrySDK(),
+		resource.WithHost(),
+		resource.WithAttributes(
+			semconv.ServiceNameKey.String("oyaki"),
+		),
+	)
+	handleErr(err, "failed to create resource")
+
+	traceClient := otlptracegrpc.NewClient(
+		otlptracegrpc.WithInsecure(),
+		otlptracegrpc.WithDialOption(grpc.WithBlock()))
+	traceExp, err := otlptrace.New(ctx, traceClient)
+	handleErr(err, "Failed to create the collector trace exporter")
+
+	samplingRate := os.Getenv("OTEL_TRACES_SAMPLING_RATE")
+	if samplingRate == "" {
+		samplingRate = "1"
+	}
+	samplingRateFloat, err := strconv.ParseFloat(samplingRate, 64)
+	if err != nil {
+		handleErr(err, "Failed to parse OTEL_TRACES_SAMPLING_RATE as float64, using default 1.0")
+	}
+	sampler := sdktrace.ParentBased(sdktrace.TraceIDRatioBased(samplingRateFloat))
+
+	bsp := sdktrace.NewBatchSpanProcessor(traceExp)
+	tracerProvider := sdktrace.NewTracerProvider(
+		sdktrace.WithSampler(sampler),
+		sdktrace.WithResource(res),
+		sdktrace.WithSpanProcessor(bsp),
+	)
+
+	// set global propagator to tracecontext (the default is no-op).
+	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
+	otel.SetTracerProvider(tracerProvider)
+
+	return func() {
+		cxt, cancel := context.WithTimeout(ctx, time.Second)
+		defer cancel()
+		if err := traceExp.Shutdown(cxt); err != nil {
+			otel.Handle(err)
+		}
+	}
+}
+
+func handleErr(err error, message string) {
+	if err != nil {
+		log.Printf("%s: %v", message, err)
+	}
+}

webp.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"io"
 	"log"
@@ -13,7 +14,10 @@ import (
 	"github.com/disintegration/imaging"
 )
 
-func doWebp(req *http.Request) (*http.Response, error) {
+func doWebp(ctx context.Context, req *http.Request) (*http.Response, error) {
+	ctx, span := tracer.Start(ctx, "doWebp")
+	defer span.End()
+
 	var orgRes *http.Response
 	orgURL := req.URL
 	newPath := orgURL.Path[:len(orgURL.Path)-len(".webp")]
@@ -44,7 +48,10 @@ func doWebp(req *http.Request) (*http.Response, error) {
 	return orgRes, nil
 }
 
-func convWebp(src io.Reader, params []string) (*bytes.Buffer, error) {
+func convWebp(ctx context.Context, src io.Reader, params []string) (*bytes.Buffer, error) {
+	ctx, span := tracer.Start(ctx, "convWebp")
+	defer span.End()
+
 	f, err := os.CreateTemp("/tmp", "")
 	if err != nil {
 		return nil, err

webp_test.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"io"
 	"net/http"
 	"net/http/httptest"
@@ -18,7 +19,9 @@ func TestProxyWebP(t *testing.T) {
 	url := ts.URL + "/oyaki.jpg.webp"
 
 	req, _ := http.NewRequest("GET", url, nil)
-	resp, err := doWebp(req)
+
+	ctx := context.Background()
+	resp, err := doWebp(ctx, req)
 	if err != nil {
 		t.Fatal(err)
 	} else {
@@ -43,12 +46,13 @@ func TestConvJPG2WebP(t *testing.T) {
 	url := ts.URL + "/oyaki.jpg.webp"
 
 	req, _ := http.NewRequest("GET", url, nil)
-	resp, err := doWebp(req)
+	ctx := context.Background()
+	resp, err := doWebp(ctx, req)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer resp.Body.Close()
-	_, err = convWebp(resp.Body, []string{})
+	_, err = convWebp(ctx, resp.Body, []string{})
 	if err != nil {
 		t.Fatal(err)
 	}