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package main
import (
"bufio"
"bytes"
"fmt"
"io/ioutil"
golog "log"
"net/http"
"os"
"runtime"
"strings"
"golang.org/x/net/context"
"github.com/opentracing/basictracer-go/examples/dapperish"
opentracing "github.com/opentracing/opentracing-go"
"github.com/opentracing/opentracing-go/ext"
"github.com/opentracing/opentracing-go/log"
)
func client() {
reader := bufio.NewReader(os.Stdin)
for {
span := opentracing.StartSpan("getInput")
ctx := opentracing.ContextWithSpan(context.Background(), span)
// Make sure that global baggage propagation works.
span.SetBaggageItem("User", os.Getenv("USER"))
span.LogFields(log.Object("ctx", ctx))
fmt.Print("\n\nEnter text (empty string to exit): ")
text, _ := reader.ReadString('\n')
text = strings.TrimSpace(text)
if len(text) == 0 {
fmt.Println("Exiting.")
os.Exit(0)
}
span.LogFields(log.String("user text", text))
httpClient := &http.Client{}
httpReq, _ := http.NewRequest("POST", "http://localhost:8080/", bytes.NewReader([]byte(text)))
textCarrier := opentracing.HTTPHeadersCarrier(httpReq.Header)
err := span.Tracer().Inject(span.Context(), opentracing.TextMap, textCarrier)
if err != nil {
panic(err)
}
resp, err := httpClient.Do(httpReq)
if err != nil {
span.LogFields(log.Error(err))
} else {
span.LogFields(log.Object("response", resp))
}
span.Finish()
}
}
func server() {
http.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
textCarrier := opentracing.HTTPHeadersCarrier(req.Header)
wireSpanContext, err := opentracing.GlobalTracer().Extract(
opentracing.TextMap, textCarrier)
if err != nil {
panic(err)
}
serverSpan := opentracing.GlobalTracer().StartSpan(
"serverSpan",
ext.RPCServerOption(wireSpanContext))
serverSpan.SetTag("component", "server")
defer serverSpan.Finish()
fullBody, err := ioutil.ReadAll(req.Body)
if err != nil {
serverSpan.LogFields(log.Error(err))
}
serverSpan.LogFields(log.String("request body", string(fullBody)))
})
golog.Fatal(http.ListenAndServe(":8080", nil))
}
func main() {
opentracing.InitGlobalTracer(dapperish.NewTracer("dapperish_tester"))
go server()
go client()
runtime.Goexit()
}
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