CookieJar不捕获传入的Cookie

Question

I'm trying to have Go submit a form on a webpage for me to simulate a login. From there I'm trying to use the cookies to keep a persistent session for one more call to a sub-page.

I'm able to successfully do the log in with no issues, I'm just having issues catching the cookies being set by the returning server. I'm wondering if it's because their login script does several redirects? (I am getting an output).

Any ideas why I'm not catching the cookies being returned?

Here is the code I'm using:

 import (
    "crypto/tls"
    "fmt"
    "io/ioutil"
    "net/http"
    "net/url"
    "strings"
    "sync"
)

type Jar struct {
    lk      sync.Mutex
    cookies map[string][]*http.Cookie
}

var CookieJar *Jar

func NewJar() *Jar {
    jar := new(Jar)
    jar.cookies = make(map[string][]*http.Cookie)
    return jar
}

// SetCookies handles the receipt of the cookies in a reply for the
// given URL.  It may or may not choose to save the cookies, depending
// on the jar's policy and implementation.
func (jar *Jar) SetCookies(u *url.URL, cookies []*http.Cookie) {
    jar.lk.Lock()
    jar.cookies[u.Host] = cookies
    jar.lk.Unlock()
}

// Cookies returns the cookies to send in a request for the given URL.
// It is up to the implementation to honor the standard cookie use
// restrictions such as in RFC 6265.
func (jar *Jar) Cookies(u *url.URL) []*http.Cookie {
    return jar.cookies[u.Host]
}

func NewClient() *http.Client {
    tr := &http.Transport{
    TLSClientConfig: &tls.Config{InsecureSkipVerify: false},
}

    CookieJar = NewJar()
    client := &http.Client{
        Transport:     tr,
        CheckRedirect: nil,
        Jar:           CookieJar,
    }

    return client
 }

 func Login() {
    client := NewClient()

    api := "https://www.statuscake.com/App/"
    uri, _ := url.Parse("https://www.statuscake.com")

    fmt.Printf("uri: %s
", uri)

    values := url.Values{}
    values.Add("username", username)
    values.Add("password", password)
    values.Add("Login", "yes")
    values.Add("redirect", "")
    str := values.Encode()
    req, err := http.NewRequest("POST", api, strings.NewReader(str))

    req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
    req.Header.Set("Accept", "text/html")
    req.Header.Set("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.65 Safari/537.36")
    cookies := CookieJar.Cookies(uri)
    for i := 0; i < len(cookies); i++ {
        fmt.Printf("Cookie[%d]: %s", i, cookies[i])
        req.AddCookie(cookies[i])
    }

    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    fmt.Printf("Response: %v
", resp)

    fmt.Printf("Response.Cookies: %v
", resp.Cookies())

    cookies = resp.Cookies()
    CookieJar.SetCookies(uri, cookies)

    defer resp.Body.Close()

    if resp.StatusCode == 200 {
        fmt.Printf("

-----
")
        fmt.Println("HTTP Code: ", resp.StatusCode)
        fmt.Println("Response Cookies: ", resp.Cookies())
        fmt.Println("Request Headers: ", req.Header)
        fmt.Println("Request Cookies: ", req.Cookies())
        fmt.Println("Response Headers: ", resp.Header)
        fmt.Printf("-----

")
    }
 }

Answer 1

Not sure where the problem really is, but two notes:

1. There is no need to populate the request manually with cookies if your Client has a working Jar. The client should handle all cookie stuff transparently for you: It extracts cookies from the response and store in the jar and populates the response with cookies from the jar (even during redirects). Maybe this overwrites your manually set cookies.

2. Do not roll your own CookieJar implementation. Cookie handling is awful (you may believe me). Just use http://golang.org/pkg/net/http/cookiejar/ maybe in combination with code.google.com/p/go.net/publicsuffix