add http post error

internal/http.go

@@ -18,7 +18,7 @@ func post(url string, contentType string, msg string) (*http.Response, error) {
 	return http.Post(url, contentType, bytes.NewBuffer([]byte(msg)))
 }
 
-func postSim(url string, msg string) string {
+func postSim(url string, msg string) (string, error) {
 	timeout := time.Duration(10 * time.Second)
 	client := http.Client{
 		Timeout: timeout,
@@ -26,24 +26,24 @@ func postSim(url string, msg string) string {
 
 	req, err := http.NewRequest(http.MethodPost, url, strings.NewReader(msg))
 	if err != nil {
-		return err.Error()
+		return err.Error(), err
 	}
 	req.Header.Set("Content-Type", defaultContentType)
 	req.Header.Set("User-Agent", defaultAgent)
 	req.Header.Set("SOAPAction", "")
 	resp, err := client.Do(req)
 	if err != nil {
-		return err.Error()
+		return err.Error(), err
 	}
 	defer resp.Body.Close()
 	respBytes, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
-		return err.Error()
+		return err.Error(), err
 	}
-	return string(respBytes)
+	return string(respBytes), nil
 }
 
 //Send message
-func Send(url string, message string) string {
+func Send(url string, message string) (string, error) {
 	return postSim(url, message)
 }