Added better support for non-github release repositories.

Fixes:
 - ros-infrastructure#101
 - ros/ros-overlay#30

src/rosdistro/rosdistro.py

@@ -197,6 +197,8 @@ def __init__(self, name, repository):
 
     def _fetch_package_xml(self, rosdistro):
         repo = self.repository
+        supported_non_githubs = [ 'gitlab', 'bitbucket' ]
+
         if 'github.com' in repo.url:
             url = repo.url
             release_tag = 'release/{0}/{1}/{2}'.format(rosdistro, self.name, repo.version)
@@ -222,7 +224,22 @@ def _fetch_package_xml(self, rosdistro):
             self._release_tags[rosdistro] = release_tag
             return package_xml, release_tag
         else:
-            raise Exception("Non-github repositories are net yet supported by the rosdistro tool")
+            release_tag = 'release/{0}/{1}/{2}'.format(rosdistro, self.name, repo.version)            
+            for nongithub in supported_non_githubs:
+                url = repo.url
+                try:
+                    url = url.replace('.git', {
+                        'gitlab' : '/raw/{0}/package.xml',
+                        'bitbucket' : '/raw/{0}/package.xml'
+                        }[nongithub].format(release_tag))
+                    package_xml = urlopen(url).read()
+                    self._package_xmls[rosdistro] = package_xml
+                    self._release_tags[rosdistro] = release_tag
+                    return package_xml, release_tag
+                except Exception as e:
+                    # If we get here, try the next one.
+                    pass
+            raise Exception('Failed to identify non-github repository type!')
 
     def get_package_xml(self, rosdistro):
         if rosdistro not in self._package_xmls: