http.Client.Do停止执行，没有任何错误

Question

I faced with weird behavior of Do function in http library. In my program I have a worker reading a channel. On each message worker calls a function which makes a http request. Here are the function:

func FetchUrlWithProxy(url string, proxy string) (*http.Response, error) {
    proxyUrl, err := urllib.Parse(proxy) // [1]
    if err != nil {
        return nil, err
    }

    client := &http.Client{Transport: &http.Transport{Proxy: http.ProxyURL(proxyUrl)}}
    request, err := http.NewRequest("GET", url, nil)
    if err != nil {
        return nil, err
    }

    log.Println("try ", url) // [2]
    response, err := client.Do(request)
    log.Println("done ", url) // [3]

    if err != nil { // [4]
        return nil, err
    }

    return response, nil
}

• [1] - it's just net/url imported this this name.
• [2] - this line is printed eveytime.
• [3] - this line is never printed without any errors/panics.
• [4] - so this checking of return value is useless. Execution doesn't reach this point.

This behavior definitely is not what I expected. But if I remove proxy usage and create client as client := &http.Client{} it will work. On other hand the proxy is not broken. I checked it using curl. How can it be?

I will provide any additional information if you need.

Answer 1

Your code seems to work - I would suspect that there is something happening with the proxy that you are actually using ?

code :

package main

import (
    "log"
    "net/http"
    urllib "net/url"
)

func FetchUrlWithProxy(url string, proxy string) (*http.Response, error) {
    proxyUrl, err := urllib.Parse(proxy) // [1]
    if err != nil {
        return nil, err
    }

    client := &http.Client{Transport: &http.Transport{Proxy: http.ProxyURL(proxyUrl)}}
    request, err := http.NewRequest("GET", url, nil)
    if err != nil {
        return nil, err
    }

    log.Println("try ", url) // [2]
    response, err := client.Do(request)
    log.Println("done ", url) // [3]

    if err != nil { // [4]
        return nil, err
    }

    return response, nil
}

func main() {
    res, err := FetchUrlWithProxy("https://www.google.com", "https://www.google.com")
    log.Printf("R %v E %v
", res, err)
}

And the output :

➜ go run p.go
2015/07/20 21:44:45 try  https://www.google.com
2015/07/20 21:44:46 done  https://www.google.com
2015/07/20 21:44:46 <nil> Get https://www.google.com: unexpected EOF