Merge lp:~morphis/jenkins-launchpad-plugin/preemptive-auth-handler into lp:jenkins-launchpad-plugin

[Simon Fels]

Use PreemptiveBasicAuthHandler authentication handler to make sure we
sent authentication headers with every request and not as urllib2 would
do when we receive a HTTP 403 error code.

Jenkins doesn't return a 401 HTTP error code to tell the client to retry with authentication details as urllib2 by default expects but sents a 403 error code straight away. See https://wiki.jenkins-ci.org/display/JENKINS/Authenticating+scripted+clients and https://stackoverflow.com/questions/16907684/fetching-a-url-from-a-basic-auth-protected-jenkins-server-with-urllib2 for details on this.

[lp:~morphis/jenkins-launchpad-plugin/preemptive-auth-handler]

134. By Simon Fels on 2017-03-03

Add missing import for base64 package

Unmerged revisions

134. By Simon Fels on 2017-03-03

Add missing import for base64 package

133. By Simon Fels on 2017-03-03

Use PreemptiveBasicAuthHandler authentication handler to make sure we
sent authentication headers with every request and not as urllib2 would
do when we receive a HTTP 403 error code.

=== modified file 'jlp/jsonjenkins.py'
--- jlp/jsonjenkins.py	2015-12-14 15:31:54 +0000
+++ jlp/jsonjenkins.py	2017-03-03 07:10:17 +0000
@@ -1,6 +1,27 @@
 import json
 import urllib2
-
+import base64
+
+# Taken from https://stackoverflow.com/questions/16907684/
+class PreemptiveBasicAuthHandler(urllib2.HTTPBasicAuthHandler):
+    '''Preemptive basic auth.
+
+    Instead of waiting for a 403 to then retry with the credentials,
+    send the credentials if the url is handled by the password manager.
+    Note: please use realm=None when calling add_password.'''
+    def http_request(self, req):
+        url = req.get_full_url()
+        realm = None
+        # this is very similar to the code from retry_http_basic_auth()
+        # but returns a request object.
+        user, pw = self.passwd.find_user_password(realm, url)
+        if pw:
+            raw = "%s:%s" % (user, pw)
+            auth = 'Basic %s' % base64.b64encode(raw).strip()
+            req.add_unredirected_header(self.auth_header, auth)
+        return req
+
+    https_request = http_request
 
 class JSONJenkins():
     urllib_opener = None
@@ -11,7 +32,7 @@
 
         passman = urllib2.HTTPPasswordMgrWithDefaultRealm()
         passman.add_password(None, jenkins_url, username, password)
-        authhandler = urllib2.HTTPBasicAuthHandler(passman)
+        authhandler = PreemptiveBasicAuthHandler(passman)
         self.urllib_opener = urllib2.build_opener(authhandler)
         urllib2.install_opener(self.urllib_opener)