Converting cURL request to http.Request - http

Question

This cURL command works how it should:
curl -i -v http://localhost:81/hallo
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 81 (#0)
> GET /hallo HTTP/1.1
> Host: localhost:81
> User-Agent: curl/7.55.1
> Accept: */*
>
1 -1 0* Connection #0 to host localhost left intact
Now I tried to do the same http-request in my go-service like this:
request, err := http.NewRequest("GET", "http://localhost:81/" + url.QueryEscape("Hallo"), nil)
client := &http.Client{}
resp, err := client.Do(request)
If I run the go code (I tried it with a test) it only produces this error: I only get the error net/http: HTTP/1.x transport connection broken: malformed HTTP status code "-1".
(I initially tried http.Get(myurl). this produces the same http Request. the current code was generated by https://mholt.github.io/curl-to-go/ )
Can anyone help me to understand why this two request produce different results?

Answer 1

Sample request and response to a really server:
[#xxxx ~]# curl -v -i 10.103.118.178:40000/ready
* About to connect() to 10.103.118.178 port 40000 (#0)
* Trying 10.103.118.178...
* Connected to 10.103.118.178 (10.103.118.178) port 40000 (#0)
> GET /ready HTTP/1.1
> User-Agent: curl/7.29.0
> Host: 10.103.118.178:40000
> Accept: */*
>
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< date: Fri, 25 Dec 2020 01:43:05 GMT
date: Fri, 25 Dec 2020 01:43:05 GMT
< content-length: 2
content-length: 2
< content-type: text/plain; charset=utf-8
content-type: text/plain; charset=utf-8
<
* Connection #0 to host 10.103.118.178 left intact
ok
You use -i to tell curl to include headers in the output. However, I cannot see any valid HTTP response header in your curl output. So probably your server is malfunctioning and did not make a valid HTTP response. So the Go program correctly reports about this, that it cannot interpret it as a valid HTTP header. (It tried to interpret it as an HTTP response header, but in where a status code should appear, it found -1 which is not a valid HTTP response code)