net/http: TLS server on a goroutine won't respond to clients on different goroutines

[gopherbot]

by elazarl:

To recreate the problem:

$ mkdir $GOPATH/httpstest
$ cd $GOPATH/httpstest
$ cat ->https_test.go
package main

import ("net/http"
        "crypto/tls"
        "testing")

func init() {
        go http.ListenAndServeTLS(":10122", "cert.pem", "key.pem", nil)
}

func TestHttps(t *testing.T) {
        var acceptAllCerts = &tls.Config{InsecureSkipVerify: true}
        client := &http.Client{Transport:&http.Transport{TLSClientConfig:acceptAllCerts}}
        _,err := client.Get("https://localhost:10122/bobo";)
        if err != nil {
                t.Error("can't connect to server",err)
        }
}

$ go test
--- FAIL: TestHttps (0.05 seconds)
        https_test.go:16: can't connect to server Get https://localhost:10122/bobo: dial tcp 127.0.0.1:10122: connection refused
FAIL
exit status 1
FAIL    _/home/vmplanet/gopath/testhttps        0.058s

Other processes can access the http-TLS server.

$ hg id
f4470a54e6db weekly/weekly.2012-03-04

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 11.04
Release:        11.04
Codename:       natty


$ uname -a
Linux ubuntu-vm 2.6.38-10-generic #46-Ubuntu SMP Tue Jun 28 15:05:41 UTC 2011 i686 i686
i386 GNU/Linux

[bradfitz]

Comment 1:

I think this is just a race.  There's no guarantee that ListenAndServeTLS will be
running by the time client.Get runs.
init runs first, but the goroutine that it starts isn't guaranteed to start running
before TestHttps.
I bet if you add a time.Sleep at the beginning of TestHttps it "works", but that's a
hacky solution.
The better solution is to start listening first with a new net.Listener, then start a
serving goroutine (using the listener you already started), and *then* make your HTTP
request.
Or just use:
http://weekly.golang.org/pkg/net/http/httptest/#NewTLSServer

Status changed to Invalid.