force option to attempt http2

[golgoth31]

Resty does not use http2 golang conn. Forcing attempt option in transport allow resty to use http2

[codecov]

Codecov Report

Merging #325 into master will decrease coverage by 0.15%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #325      +/-   ##
==========================================
- Coverage   95.64%   95.48%   -0.16%     
==========================================
  Files           9        9              
  Lines        1195     1197       +2     
==========================================
  Hits         1143     1143              
- Misses         30       31       +1     
- Partials       22       23       +1     

Impacted Files	Coverage Δ
client.go	96.27% <100.00%> (-0.61%)	⬇️

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[jeevatkm]

@golgoth31 Thanks for submitting the PR.

By default Go HTTP client capable of handling HTTP2 and 1.1; what is the problem?

I would like to understand the problem you're trying to solve. How is a clone is solving the problem?

FYI, due to supported API
This PR has failing build https://www.travis-ci.org/github/go-resty/resty/jobs/671228244

[golgoth31]

Hi, Thank you for your answer.
I'm ok to say that, by default, GO HTTP client is http/2 aware but, in the resty client definition, you create a totally new transport layer based on the Transport struct. This layer is not http/2 aware by default, leading your client not using http/2. It's not really clear but it's explained here: https://golang.org/src/net/http/transport.go

// ForceAttemptHTTP2 controls whether HTTP/2 is enabled when a non-zero
// Dial, DialTLS, or DialContext func or TLSClientConfig is provided.
// By default, use of any those fields conservatively disables HTTP/2.
// To use a custom dialer or TLS config and still attempt HTTP/2
// upgrades, set this to true.

I wrote a simple main file:

package main

import (
	"fmt"
	"net/http"
	"github.com/go-resty/resty/v2"
)

func main() {
	client := resty.New()
	rresp, _ := client.R().Get("https://httpbin.org/ip")
	fmt.Printf("resty response protocol: %s\n", rresp.RawResponse.Proto)

	httpclient := http.DefaultClient
	hresp, _ := httpclient.Get("https://httpbin.org/ip")
	fmt.Printf("net/http response protocol: %s\n", hresp.Proto)
}

The result is as follow:

• without my patch:
  ❯ go run test.go
  resty response protocol: HTTP/1.1
  net/http response protocol: HTTP/2.0
• with my patch:
  ❯ go run test.go
  resty response protocol: HTTP/2.0
  net/http response protocol: HTTP/2.0

As shown, the current resty client is not http/2.

For the CI problem, between 1.12 and 1.13, the http2 transport enabling has been changed. I will investigate on that.

[jeevatkm]

@golgoth31 Thanks for submitting PR. And providing insight into the issue.
golang.org/x/net/http2 package is part of the language since go1.6. So externally referring is not required.

I will investigate http2 and address it. Thanks again.

[jeevatkm]

@golgoth31 Just now I have analyzed it using your code snippet.

• It seems HTTP 2.0 broken go1.13 onwards
• It was working until go1.12
• So, it's clearly evident it was working up to go1.12 so I did not go further.

Results are -

Broken on go.14

Broken on go.13

Success on go.12

Success on go.11

[jeevatkm]

@golgoth31 Closing this PR in-favor of #339