Complete tracing using zipkin-go - go

Question

I have some services. I want to trace those services using zipkin-go. In every service, I am calling some of my other internal services or db calls. I want to trace every activity like how much time it has taken to call internal services or db. I have implemented using available tutorials on internet. Below is my code:
package main
import (
"fmt"
"os"
"net/http"
"log"
"github.com/gorilla/handlers"
"github.com/gorilla/mux"
"Upload-Image-API/services/controllers/updatemodrefid"
"Upload-Image-API/services/controllers/uploadimage"
"Upload-Image-API/services/utils"
"github.com/openzipkin/zipkin-go"
"github.com/openzipkin/zipkin-go/model"
zipkinhttp "github.com/openzipkin/zipkin-go/middleware/http"
reporterhttp "github.com/openzipkin/zipkin-go/reporter/http"
)
const endpointURL = "http://localhost:9411/api/v2/spans"
func newTracer() (*zipkin.Tracer, error) {
// The reporter sends traces to zipkin server
reporter := reporterhttp.NewReporter(endpointURL)
port := utils.GetString("serviceListeningPort")
if port == "" {
fmt.Println("Port is not defined in configuration ...!!!")
os.Exit(1)
}
// Local endpoint represent the local service information
localEndpoint := &model.Endpoint{ServiceName: "Upload-Image-API", Port: 7795}
// Sampler tells you which traces are going to be sampled or not. In this case we will record 100% (1.00) of traces.
sampler, err := zipkin.NewCountingSampler(1)
if err != nil {
return nil, err
}
t, err := zipkin.NewTracer(
reporter,
zipkin.WithSampler(sampler),
zipkin.WithLocalEndpoint(localEndpoint),
)
if err != nil {
return nil, err
}
return t, err
}
func main() {
var err error
var environment = os.Args[1]
err = utils.LoadDefaultConfig(environment)
tracer, err := newTracer()
if err != nil {
log.Fatal(err)
}
// We add the instrumented transport to the defaultClient
// that comes with the zipkin-go library
http.DefaultClient.Transport, err = zipkinhttp.NewTransport(
tracer,
zipkinhttp.TransportTrace(true),
)
if err != nil {
log.Fatal(err)
}
if err != nil {
fmt.Println("Could not load the configuration because of following err " + err.Error() + " ...!!!")
os.Exit(1)
} else {
fmt.Println("Configurations sucessfully loaded for environment " + environment + " ...!!!")
}
allowedHeaders := handlers.AllowedHeaders([]string{"X-Requested-With"})
allowedOrigins := handlers.AllowedOrigins([]string{"*"})
allowedMethods := handlers.AllowedMethods([]string{"GET", "HEAD", "POST", "PUT", "DELETE", "OPTIONS"})
port := utils.GetString("serviceListeningPort")
if port == "" {
fmt.Println("Port is not defined in configuration ...!!!")
os.Exit(1)
}
router := mux.NewRouter().StrictSlash(true)
router.HandleFunc("/uploadimage", uploadimage.UploadImages).Methods("POST", "GET")
router.HandleFunc("/updatemodrefid", updatemodrefid.UpdateModRefId).Methods("POST", "GET")
router.Use(zipkinhttp.NewServerMiddleware(
tracer,
zipkinhttp.SpanName("request")), // name for request span
)
err = http.ListenAndServe(port, handlers.CORS(allowedHeaders, allowedOrigins, allowedMethods)(router))
if err != nil {
fmt.Println("Count not start the server because of following err " + err.Error())
return
}
}
I am getting my request traced but I am not able to trace what is happening inside the uploadimage controller. Below is the screenshot of my zipkin UI:
I want to trace all the activities happening inside uploadimage controller. What should I need to pass so that I can trace all.

Answer 1

I am new to zipkin and golang, If you want to trace internal process, then you can create span from context
example: say you have api called Login, inside login you might perform database operation or any other operations
func Login(res http.ResponseWriter, req *http.Request) {
span, _ := tracer.StartSpanFromContext(req.Context(), "database")
databaseOperation()
span.Finish()
}