authenticated http client requests from golang

问题:

I have the following code:

client := &http.Client{}

/* Authenticate */
req, err := http.NewRequest("GET", "http://164.99.113.32/Authenticate", nil)
req.SetBasicAuth("<username>","<password>")
resp, err := client.Do(req)
if err != nil {
    fmt.Printf("Error : %s", err)
}

/* Get Details */
req.URL, _ = url.Parse("http://164.99.113.32/Details")
resp, err = client.Do(req)
if err != nil {
    fmt.Printf("Error : %s", err)
}

Now, the second http call is failing with a 401 access-denied error. A different REST client (a firefox plugin) correctly gets the details from the server, so I know that nothing is wrong on the server side. Do I need to pass some kind of session string or something that we got in the previous request ?

回答1:

Okay. I have resolved this. I just needed to create a cookie jar.

I am surprised that this is not handled by default by the golang http req/client class.

The code that I had to use was:

type myjar struct {
    jar map[string] []*http.Cookie
}

func (p* myjar) SetCookies(u *url.URL, cookies []*http.Cookie) {
    fmt.Printf("The URL is : %s\n", u.String())
    fmt.Printf("The cookie being set is : %s\n", cookies)
    p.jar [u.Host] = cookies
}

func (p *myjar) Cookies(u *url.URL) []*http.Cookie {
    fmt.Printf("The URL is : %s\n", u.String())
    fmt.Printf("Cookie being returned is : %s\n", p.jar[u.Host])
    return p.jar[u.Host]
}

and then in main:

    jar := &myjar{}
    jar.jar = make(map[string] []*http.Cookie)
    client.Jar = jar

Works.

回答2:

With HTTP Basic Authentication, the credentials are required for every request. Try copying the

req.SetBasicAuth("<username>", "<password>")

line before the second client.Do(req).

The reason the Firefox plugin gets the details is that the browser will cache HTTP Basic Authentication tokens for subsequent use.

回答3:

There is a new official library, maybe this is helpful.

http://golang.org/pkg/net/http/cookiejar/

example: Golang: how to follow location with cookie