tracer detection shifted to config

examples/simple-api/Dockerfile

@@ -0,0 +1,15 @@
+FROM golang:1.16
+
+RUN mkdir /src/
+WORKDIR /src/
+COPY . .
+RUN go get ./...
+RUN go build -ldflags "-linkmode external -extldflags -static" -a main.go
+
+FROM alpine:latest
+RUN apk add --no-cache tzdata ca-certificates
+COPY --from=0 /src/main /main
+COPY --from=0 /src/configs /configs
+EXPOSE 9000
+
+CMD ["/main"]

pkg/gofr/gofr.go

@@ -1,20 +1,18 @@
 package gofr
 
 import (
+	"fmt"
+	"github.com/vikash/gofr/pkg/gofr/config"
 	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/zipkin"
 	"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"
 	"log"
-	"net"
 	"os"
 	"strconv"
 	"sync"
-	"time"
-
-	"github.com/vikash/gofr/pkg/gofr/config"
-	"go.opentelemetry.io/otel/exporters/zipkin"
-	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 
 	gofrHTTP "github.com/vikash/gofr/pkg/gofr/http"
 )
@@ -130,20 +128,16 @@ func (a *App) SubCommand(pattern string, handler Handler) {
 }
 
 func (a *App) initTracer() {
-	// If zipkin is running on default port - start tracing
-	conn, err := net.DialTimeout("tcp", net.JoinHostPort("localhost", "9411"), 2*time.Second) //nolint:gomnd
-
-	if err != nil || conn == nil {
-		a.container.Logf("Tracer detection error: %v", err)
-		a.container.Log("To enable tracing locally, Run: docker run -d -p 9411:9411 openzipkin/zipkin")
-
+	tracerHost := a.Config.Get("TRACER_HOST")
+	tracerPort := a.Config.GetOrDefault("TRACER_PORT", "9411")
+	if tracerHost == "" {
 		return
 	}
 
 	a.container.Log("Exporting traces to zipkin.")
 
 	exporter, err := zipkin.New(
-		"http://localhost:9411/api/v2/spans",
+		fmt.Sprintf("http://%s:%s/api/v2/spans", tracerHost, tracerPort),
 		zipkin.WithSDKOptions(sdktrace.WithSampler(sdktrace.AlwaysSample())),
 	)
 

pkg/gofr/handler.go

@@ -28,6 +28,5 @@ type handler struct {
 
 func (h handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	c := newContext(http2.NewResponder(w), http2.NewRequest(r), h.container)
-	defer c.Trace("gofr-handler").End()
 	c.responder.Respond(h.function(c))
 }

pkg/gofr/http/router.go

@@ -1,7 +1,6 @@
 package http
 
 import (
-	"fmt"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"net/http"
 
@@ -29,6 +28,6 @@ func NewRouter() *Router {
 }
 
 func (rou *Router) Add(method, pattern string, handler http.Handler) {
-	h := otelhttp.NewHandler(handler, fmt.Sprintf("%s %s", method, pattern))
+	h := otelhttp.NewHandler(handler, "gofr-handler")
 	rou.Router.NewRoute().Methods(method).Path(pattern).Handler(h)
 }

pkg/gofr/service/new.go

@@ -1,12 +1,12 @@
 package service
 
 import (
+	"context"
 	"fmt"
-	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"go.opentelemetry.io/otel"
 	"net/http"
-	"context"
 	"net/http/httptrace"
 )
 
@@ -20,8 +20,6 @@ func (h *httpService) Get(ctx context.Context, path string, params map[string]in
 
 	uri := h.url + "/" + path
 
-	fmt.Sprintf("Making a request to %s\n", uri)
-
 	tr := otel.Tracer("gofr-http-client")
 	ctx, span := tr.Start(ctx, uri)
 	defer span.End()