Point roles docs bugs to openstack-ansible LP

Currently when clicking on the small bug in the roles'
docs, we land on openstack-manuals launchpad.

This should solve it.

Change-Id: I7a20b4a0c43ff61f72678a65e57d55d26abcae02

doc/source/conf.py

@@ -83,6 +83,22 @@ release = version_info.version_string_with_vcs()
 # The short X.Y version.
 version = version_info.canonical_version_string()
 
+# A few variables have to be set for the log-a-bug feature.
+#   giturl: The location of conf.py on Git. Must be set manually.
+#   gitsha: The SHA checksum of the bug description.
+#           Automatically extracted from git log.
+#   bug_tag: Tag for categorizing the bug. Must be set manually.
+# These variables are passed to the logabug code via html_context.
+giturl = ("http://git.openstack.org/cgit/openstack/{0}"
+          "/tree/doc/source").format(target_name)
+git_cmd = "/usr/bin/git log | head -n1 | cut -f2 -d' '"
+gitsha = os.popen(git_cmd).read().strip('\n')
+bug_project = project.lower()
+bug_title = "Documentation bug"
+html_context = {"gitsha": gitsha, "giturl": giturl,
+                "bug_tag": "docs", "bug_title": bug_title,
+                "bug_project": bug_project}
+
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
 #