How to implement cookie support in ruby net/http?

I'd like to add cookie support to a ruby class utilizing net/http to browse the web. Cookies have to be stored in a file to survive after the script has ended. Of course I can read the specs and write some kind of a handler, use some cookie.txt format and so on, but it seems to mean reinventing the wheel. Is there a better way to accomplish this task? Maybe some kind of a cooie jar class to take care of cookies?

The accepted answer will not work if your server returns and expects multiple cookies. This could happen, for example, if the server returns a set of FedAuth[n] cookies. If this affects you, you might want to look into using something along the lines of the following instead:

http = Net::HTTP.new('https://example.com', 443)
http.use_ssl = true
path1 = '/index.html'
path2 = '/index2.html'

# make a request to get the server's cookies
response = http.get(path)
if (response.code == '200')
    all_cookies = response.get_fields('set-cookie')
    cookies_array = Array.new
    all_cookies.each { | cookie |
        cookies_array.push(cookie.split('; ')[0])
    }
    cookies = cookies_array.join('; ')

    # now make a request using the cookies
    response = http.get(path2, { 'Cookie' => cookies })
end

Taken from DZone Snippets

http = Net::HTTP.new('profil.wp.pl', 443)
http.use_ssl = true
path = '/login.html'

# GET request -> so the host can set his cookies
resp, data = http.get(path, nil)
cookie = resp.response['set-cookie'].split('; ')[0]


# POST request -> logging in
data = 'serwis=wp.pl&url=profil.html&tryLogin=1&countTest=1&logowaniessl=1&login_username=blah&login_password=blah'
headers = {
  'Cookie' => cookie,
  'Referer' => 'http://profil.wp.pl/login.html',
  'Content-Type' => 'application/x-www-form-urlencoded'
}

resp, data = http.post(path, data, headers)


# Output on the screen -> we should get either a 302 redirect (after a successful login) or an error page
puts 'Code = ' + resp.code
puts 'Message = ' + resp.message
resp.each {|key, val| puts key + ' = ' + val}
puts data

update

#To save the cookies, you can use PStore
cookies = PStore.new("cookies.pstore")

# Save the cookie  
cookies.transaction do
  cookies[:some_identifier] = cookie
end

# Retrieve the cookie back
cookies.transaction do
  cookie = cookies[:some_identifier] 
end

The accepted answer does not work. You need to access the internal representation of the response header where the multiple set-cookie values are stores separately and then remove everything after the first semicolon from these string and join them together. Here is code that works

r = http.get(path)
cookie = {'Cookie'=>r.to_hash['set-cookie'].collect{|ea|ea[/^.*?;/]}.join}
r = http.get(next_path,cookie)

Use http-cookie, which implements RFC-compliant parsing and rendering, plus a jar.

A crude example that happens to follow a redirect post-login:

require 'uri'
require 'net/http'
require 'http-cookie'

uri = URI('...')
jar = HTTP::CookieJar.new

Net::HTTP.start(uri.host, uri.port, use_ssl: uri.scheme == 'https') do |http|
  req = Net::HTTP::Post.new uri
  req.form_data = { ... }
  res = http.request req
  res.get_fields('Set-Cookie').each do |value|
    jar.parse(value, req.uri)
  end

  fail unless res.code == '302'

  req = Net::HTTP::Get.new(uri + res['Location'])
  req['Cookie'] = HTTP::Cookie.cookie_value(jar.cookies(uri))
  res = http.request req
end

Why do this? Because the answers above are incredibly insufficient and flat out don't work in many RFC-compliant scenarios (happened to me), so relying on the very lib implementing just what's needed is infinitely more robust if you want to handle more than one particular case.

I've used Curb and Mechanize for a similar project. Just enable cookies support and save the cookies to a temp cookiejar... If your using net/http or packages without cookie support built in, you will need to write your own cookie handling.

You can send receive cookies using headers.

You can store the header in any persistence framework. Whether it is some sort of database, or files.