use either pycurl or wget to download from launchpad, also improve error message…

use either pycurl or wget to download from launchpad, also improve error message if neither is installed

library/packaging/apt_repository

@@ -30,6 +30,7 @@ notes:
     - This module works on Debian and Ubuntu and requires only C(python-apt) package.
     - This module supports Debian Squeeze (version 6) as well as its successors.
     - This module treats Debian and Ubuntu distributions separately. So PPA could be installed only on Ubuntu machines.
+    - For PPA support you either need python-pycurl or wget on the client.
 options:
     repo:
         required: true
@@ -66,8 +67,8 @@ import glob
 import json
 import os
 import re
+import subprocess
 import tempfile
-import pycurl
 
 try:
     import apt_pkg
@@ -80,6 +81,7 @@ except ImportError:
 
 VALID_SOURCE_TYPES = ('deb', 'deb-src')
 
+
 class CurlCallback:
     def __init__(self):
         self.contents = ''
@@ -87,10 +89,20 @@ class CurlCallback:
     def body_callback(self, buf):
         self.contents = self.contents + buf
 
+
 class InvalidSource(Exception):
     pass
 
 
+def get_executable_from_path(cmd):
+    full_path = [os.path.join(p, cmd)
+                 for p in os.environ.get("PATH", "").split(":")
+                 if os.path.isfile(os.path.join(p, cmd))]
+    if full_path:
+        return full_path[0]
+    return None
+
+
 # Simple version of aptsources.sourceslist.SourcesList.
 # No advanced logic and no backups inside.
 class SourcesList(object):
@@ -250,12 +262,30 @@ class SourcesList(object):
 
 
 class UbuntuSourcesList(SourcesList):
+
+    LP_API = 'https://launchpad.net/api/1.0/~%s/+archive/%s' 
+
     def __init__(self, add_ppa_signing_keys_callback=None):
         self.add_ppa_signing_keys_callback = add_ppa_signing_keys_callback
         super(UbuntuSourcesList, self).__init__()
 
     def _get_ppa_info(self, owner_name, ppa_name):
-        lp_api = 'https://launchpad.net/api/1.0/~%s/+archive/%s' % (owner_name, ppa_name)
+        # we can not use urllib2 here as it does not do cert verification
+        lp_api = self.LP_API % (owner_name, ppa_name)
+        try:
+            return self._get_ppa_info_curl(lp_api)
+        except ImportError:
+            return self._get_ppa_info_wget(lp_api)
+
+    def _get_ppa_info_wget(self, lp_api):
+        wget = get_executable_from_path("wget")
+        p = subprocess.Popen([wget, "-q", "-O", "-",
+                              "--header=Accept: application/json",
+                              lp_api], stdout=subprocess.PIPE)
+        return json.loads(p.communicate()[0])
+
+    def _get_ppa_info_curl(self, lp_api):
+        import pycurl
         callback = CurlCallback()
         curl = pycurl.Curl()
         curl.setopt(pycurl.SSL_VERIFYPEER, 1)
@@ -321,6 +351,15 @@ def main():
     if not HAVE_PYTHON_APT:
         module.fail_json(msg='Could not import python modules: apt_pkg. Please install python-apt package.')
 
+    # see if we have something that can download from https with cert
+    # checking
+    try:
+        import pycurl
+    except ImportError:
+        wget = get_executable_from_path("wget")
+        if not wget:
+            module.fail_json(msg="Need the python-pycurl or wget package")
+
     repo = module.params['repo']
     state = module.params['state']
     sourceslist = None