hystrix POST with retry returns "http: ContentLength=... with Body length 0"

[sebastian-popa]

It looks like the retries with POST used in a hystrix client run into some error related to the request being already used. Error returned from http call is "{"status":"Post "http://localhost:8080/sampleLookup\": http: ContentLength=14 with Body length 0"}", which seems incorrect - we shouldn't run into an issue of request being reused several times.

Did anyone encounter this?

Thanks!

Source code following, curl command under the code.

package main

import (
	"bytes"
	"encoding/json"
	"io/ioutil"
	"log"
	"net/http"
	"time"

	hystrix "github.com/gojek/heimdall/v7/hystrix"
)

type SampleRequest struct {
	String string `json:"string"`
}

type SampleResponse struct {
	Status string `json:"status"`
}

func initialEndpoint(w http.ResponseWriter, r *http.Request) {
	var sampleRequest SampleRequest

	// hystrix client
	client := hystrix.NewClient(
		hystrix.WithHystrixTimeout(1000*time.Millisecond),
		hystrix.WithRetryCount(3),
	)

	// request buffer
	var buf bytes.Buffer
	_ = json.NewEncoder(&buf).Encode(sampleRequest)

	// send request
	headers := http.Header{}
	headers.Set("Content-Type", "application/json")
	res, err := client.Post("http://localhost:8080/sampleLookup", &buf, headers)

	// interpret response
	if err != nil {
		sampleResponse := SampleResponse{
			Status: err.Error(),
		}
		json.NewEncoder(w).Encode(sampleResponse)
		return
	}
	body, _ := ioutil.ReadAll(res.Body)
	json.NewEncoder(w).Encode(body)
	res.Body.Close()
}

// just wait for 3 sec
func sampleLookup(w http.ResponseWriter, r *http.Request) {
	time.Sleep(3 * time.Second)
	json.NewEncoder(w).Encode(SampleResponse{
		Status: "ok",
	})
}

// start server with 2 endpoints
func main() {
	http.HandleFunc("/initialEndpoint", initialEndpoint)
	http.HandleFunc("/sampleLookup", sampleLookup)
	log.Fatal(http.ListenAndServe(":8080", nil))
}

Curl command:

curl --location --request GET 'http://localhost:8080/initialEndpoint' \
--header 'Content-Type: text/plain' \
--data-raw '{
    "String": "some value"
}'