Checking if the endpoint is down when connecting

e2e/basic/basic.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/TykTechnologies/opentelemetry/config"
 	"github.com/TykTechnologies/opentelemetry/trace"
+	"github.com/sirupsen/logrus"
 	"go.opentelemetry.io/otel/attribute"
 )
 
@@ -22,14 +23,14 @@ func main() {
 	cfg := config.OpenTelemetry{
 		Enabled:           true,
 		Exporter:          "grpc",
-		Endpoint:          "otel-collector:4317",
+		Endpoint:          "localhost:4317",
 		ConnectionTimeout: 10,
 		ResourceName:      "e2e-basic",
 	}
 
 	log.Println("Initializing OpenTelemetry at e2e-basic:", cfg.Endpoint)
 
-	provider, err := trace.NewProvider(trace.WithContext(ctx), trace.WithConfig(&cfg))
+	provider, err := trace.NewProvider(trace.WithContext(ctx), trace.WithConfig(&cfg), trace.WithLogger(logrus.New()))
 	if err != nil {
 		log.Printf("error on otel provider init %s", err.Error())
 		return

e2e/basic/go.mod

@@ -4,6 +4,7 @@ go 1.19
 
 require (
 	github.com/TykTechnologies/opentelemetry v0.0.0-20230627083938-06db14948ffe
+	github.com/sirupsen/logrus v1.9.3
 	go.opentelemetry.io/otel v1.16.0
 )
 

e2e/basic/go.sum

@@ -53,6 +53,7 @@ github.com/cncf/xds/go v0.0.0-20210922020428-25de7278fc84/go.mod h1:eXthEFrGJvWH
 github.com/cncf/xds/go v0.0.0-20211011173535-cb28da3451f1/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
@@ -146,6 +147,7 @@ github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
@@ -289,6 +291,7 @@ golang.org/x/sys v0.0.0-20200803210538-64077c9b5642/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.9.0 h1:KS/R3tvhPqvJvwcKfnBHJwwthS11LRhmM5D59eEXa0s=
 golang.org/x/sys v0.9.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=

trace/exporter.go

@@ -3,6 +3,9 @@ package trace
 import (
 	"context"
 	"fmt"
+	"net"
+	"net/http"
+	"strings"
 	"time"
 
 	"github.com/TykTechnologies/opentelemetry/config"
@@ -13,24 +16,44 @@ import (
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 )
 
-func exporterFactory(ctx context.Context, cfg *config.OpenTelemetry) (sdktrace.SpanExporter, error) {
+func exporterFactory(ctx context.Context, provider *traceProvider) (sdktrace.SpanExporter, error) {
 	var client otlptrace.Client
 
-	switch cfg.Exporter {
+	switch provider.cfg.Exporter {
 	case config.GRPCEXPORTER:
-		client = newGRPCClient(ctx, cfg)
+		client = newGRPCClient(ctx, provider.cfg)
+
+		if !isGRPCEndpointActive(provider.cfg.Endpoint) {
+			provider.logger.Error("GRPC endpoint: ", provider.cfg.Endpoint, " is down")
+		}
 	case config.HTTPEXPORTER:
-		client = newHTTPClient(ctx, cfg)
+		client = newHTTPClient(ctx, provider.cfg)
+
+		if !isHTTPEndpointActive(provider.cfg.Endpoint) {
+			provider.logger.Error("HTTP endpoint: ", provider.cfg.Endpoint, " is down")
+		}
 	default:
-		return nil, fmt.Errorf("invalid exporter type: %s", cfg.Exporter)
+		return nil, fmt.Errorf("invalid exporter type: %s", provider.cfg.Exporter)
 	}
 
-	ctx, cancel := context.WithTimeout(ctx, time.Duration(cfg.ConnectionTimeout)*time.Second)
+	ctx, cancel := context.WithTimeout(ctx, time.Duration(provider.cfg.ConnectionTimeout)*time.Second)
 	defer cancel()
 	// Create the trace exporter
 	return otlptrace.New(ctx, client)
 }
 
+func isGRPCEndpointActive(endpoint string) bool {
+	conn, err := net.DialTimeout("tcp", endpoint, time.Second)
+
+	if err != nil {
+		return false
+	}
+
+	conn.Close()
+
+	return true
+}
+
 func newGRPCClient(ctx context.Context, cfg *config.OpenTelemetry) otlptrace.Client {
 	return otlptracegrpc.NewClient(
 		otlptracegrpc.WithEndpoint(cfg.Endpoint),
@@ -39,6 +62,27 @@ func newGRPCClient(ctx context.Context, cfg *config.OpenTelemetry) otlptrace.Cli
 	)
 }
 
+func isHTTPEndpointActive(endpoint string) bool {
+	client := http.Client{
+		Timeout: time.Second,
+	}
+
+	// Check if the endpoint has a protocol scheme (http/https), if not, append one
+	if !strings.HasPrefix(strings.ToLower(endpoint), "http") {
+		endpoint = "http://" + endpoint
+	}
+
+	// Using Head method to avoid downloading the whole body
+	req, err := http.NewRequestWithContext(context.Background(), http.MethodHead, endpoint, nil)
+	if err != nil {
+		return false
+	}
+
+	_, err = client.Do(req)
+
+	return err == nil
+}
+
 func newHTTPClient(ctx context.Context, cfg *config.OpenTelemetry) otlptrace.Client {
 	return otlptracehttp.NewClient(
 		otlptracehttp.WithEndpoint(cfg.Endpoint),

trace/exporter_test.go

@@ -109,8 +109,11 @@ func Test_ExporterFactory(t *testing.T) {
 
 				tc.givenConfig.Endpoint = endpoint
 			}
-
-			exporter, err := exporterFactory(ctx, tc.givenConfig)
+			provider := &traceProvider{
+				cfg:    tc.givenConfig,
+				logger: &mockLogger{},
+			}
+			exporter, err := exporterFactory(ctx, provider)
 			if tc.expectedErr != nil {
 				assert.NotNil(t, err)
 				assert.Equal(t, tc.expectedErr.Error(), err.Error())

trace/provider.go

@@ -89,7 +89,7 @@ func NewProvider(opts ...Option) (Provider, error) {
 	}
 
 	// create the exporter - here's where connecting to the collector happens
-	exporter, err := exporterFactory(provider.ctx, provider.cfg)
+	exporter, err := exporterFactory(provider.ctx, provider)
 	if err != nil {
 		provider.logger.Error("failed to create exporter", err)
 		return provider, fmt.Errorf("failed to create exporter: %w", err)
@@ -133,7 +133,6 @@ func NewProvider(opts ...Option) (Provider, error) {
 	})
 
 	provider.logger.Info("Tracer provider initialized successfully")
-
 	return provider, nil
 }