sphinxext: Start parsing 'Opt.help' as rST

Users expect this to be parsed as rST and write their docstrings
accordingly. This has the potential to introduce warnings for users with
improperly formatted rST and these warnings can be promoted to errors if
'sphinx-build' is used with the '-W' option. As a result, we disable the
'warning-is-error' logger for these options. We may wish to change this
behavior in the future.

It is not really possible to test this yet as the output wouldn't look
much different. In addition, the error messages generated are rather
unhelpful. Both of these can be changed in a future modification.

Change-Id: Ic6c2dcbe7823dd3fdc71db8dc5afab2d604559e3
Closes-Bug: #1755783

oslo_config/sphinxext.py

@@ -20,6 +20,7 @@
 from sphinx.domains import Domain
 from sphinx.domains import ObjType
 from sphinx.roles import XRefRole
+from sphinx.util import logging
 from sphinx.util.nodes import make_refnode
 from sphinx.util.nodes import nested_parse_with_titles
 
@@ -53,7 +54,7 @@ def _list_table(headers, data, title='', columns=None):
 
 def _indent(text, n=2):
     padding = ' ' * n
-    return '\n'.join(padding + l for l in text.splitlines())
+    return '\n'.join(padding + l if l else l for l in text.splitlines())
 
 
 def _make_anchor_target(group_name, option_name):
@@ -98,8 +99,9 @@ def _format_opt(opt, group_name):
     yield _indent(':Type: %s' % opt_type)
     for default in generator._format_defaults(opt):
         if default:
-            default = '``' + default + '``'
-        yield _indent(':Default: %s' % default)
+            yield _indent(':Default: ``%s``' % default)
+        else:
+            yield _indent(':Default: ``%r``' % default)
     if getattr(opt.type, 'min', None) is not None:
         yield _indent(':Minimum Value: %s' % opt.type.min)
     if getattr(opt.type, 'max', None) is not None:
@@ -148,7 +150,8 @@ def _format_opt(opt, group_name):
         help_text = opt.help
     if help_text:
         yield ''
-        yield _indent(help_text.strip())
+        for line in help_text.strip().splitlines():
+            yield _indent(line.rstrip())
 
     # We don't bother outputting this if not using new-style choices with
     # inline descriptions
@@ -183,8 +186,10 @@ def _format_opt(opt, group_name):
         yield _indent('   Its value may be silently ignored ')
         yield _indent('   in the future.')
         if opt.deprecated_reason:
+            reason = ' '.join([x.strip() for x in
+                               opt.deprecated_reason.splitlines()])
             yield ''
-            yield _indent('   :Reason: ' + opt.deprecated_reason)
+            yield _indent('   :Reason: ' + reason)
 
     yield ''
 
@@ -307,7 +312,14 @@ def run(self):
 
         node = nodes.section()
         node.document = self.state.document
-        nested_parse_with_titles(self.state, result, node)
+
+        # With the resolution for bug #1755783, we now parse the 'Opt.help'
+        # attribute as rST. Unfortunately, there are a lot of broken option
+        # descriptions out there and we don't want to break peoples' builds
+        # suddenly. As a result, we disable 'warning-is-error' temporarily.
+        # Users will still see the warnings but the build will continue.
+        with logging.skip_warningiserror():
+            nested_parse_with_titles(self.state, result, node)
 
         return node.children