Prevent doc generation failure on OVO decorators

Currently Sphinx will fail to generate the documentation if we are using
decorators from any OVO in cinder.objects, because the OVOs are only
added to the cinder.objects namespace when the CLI programs are run.

So we need to run `register_all` method during documentation generation
to avoid failures like:

    AttributeError: 'module' object has no attribute 'Volume'

This patch modifies autogenerated doc/source/conf.py file and since now
it is no longer completely autogenerated it is added to PEP8 checks,
which required some minor changes.

Change-Id: Ifeeef61a778f9e3f3daceba8ed05cd2036219499

doc/source/conf.py

@@ -1,3 +1,15 @@
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
 # cinder documentation build configuration file, created by
 # sphinx-quickstart on Sat May  1 15:17:47 2010.
 #
@@ -15,6 +27,16 @@ import subprocess
 import sys
 import warnings
 
+from cinder import objects
+
+
+# NOTE(geguileo): Sphinx will fail to generate the documentation if we are
+# using decorators from any OVO in cinder.objects, because the OVOs are only
+# added to the cinder.objects namespace when the CLI programs are run.  So we
+# need to run it here as well to avoid failures like:
+#    AttributeError: 'module' object has no attribute 'Volume'
+objects.register_all()
+
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
@@ -38,7 +60,8 @@ extensions = ['sphinx.ext.autodoc',
               'ext.cinder_driverlist',
               ]
 
-config_generator_config_file = '../../cinder/config/cinder-config-generator.conf'
+config_generator_config_file = (
+    '../../cinder/config/cinder-config-generator.conf')
 sample_config_basename = '_static/cinder'
 
 # autodoc generation is a bit aggressive and a nuisance
@@ -63,7 +86,7 @@ else:
 source_suffix = '.rst'
 
 # The encoding of source files.
-#source_encoding = 'utf-8'
+# source_encoding = 'utf-8'
 
 # The master toctree document.
 master_doc = 'index'
@@ -84,13 +107,13 @@ version = version_info.version_string()
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
-#language = None
+# language = None
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
-#today = ''
+# today = ''
 # Else, today_fmt is used as the format for a strftime call.
-#today_fmt = '%B %d, %Y'
+# today_fmt = '%B %d, %Y'
 
 # List of documents that shouldn't be included in the build.
 unused_docs = [
@@ -104,10 +127,10 @@ exclude_trees = []
 
 # The reST default role (used for this markup: `text`) to use
 # for all documents.
-#default_role = None
+# default_role = None
 
 # If true, '()' will be appended to :func: etc. cross-reference text.
-#add_function_parentheses = True
+# add_function_parentheses = True
 
 # If true, the current module name will be prepended to all description
 # unit titles (such as .. function::).
@@ -143,26 +166,26 @@ man_pages = [
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
 # documentation.
-#html_theme_options = {}
+# html_theme_options = {}
 
 # Add any paths that contain custom themes here, relative to this directory.
-#html_theme_path = []
+# html_theme_path = []
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
-#html_title = None
+# html_title = None
 
 # A shorter title for the navigation bar.  Default is the same as html_title.
-#html_short_title = None
+# html_short_title = None
 
 # The name of an image file (relative to this directory) to place at the top
 # of the sidebar.
-#html_logo = None
+# html_logo = None
 
 # The name of an image file (within the static path) to use as favicon of the
 # docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
 # pixels large.
-#html_favicon = None
+# html_favicon = None
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
@@ -171,9 +194,9 @@ html_static_path = ['_static']
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
-#html_last_updated_fmt = '%b %d, %Y'
+# html_last_updated_fmt = '%b %d, %Y'
 git_cmd = ["git", "log", "--pretty=format:'%ad, commit %h'", "--date=local",
-    "-n1"]
+           "-n1"]
 try:
     html_last_updated_fmt = subprocess.Popen(
         git_cmd, stdout=subprocess.PIPE).communicate()[0]
@@ -183,34 +206,34 @@ except Exception:
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
-#html_use_smartypants = True
+# html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
-#html_sidebars = {}
+# html_sidebars = {}
 
 # Additional templates that should be rendered to pages, maps page names to
 # template names.
-#html_additional_pages = {}
+# html_additional_pages = {}
 
 # If false, no module index is generated.
-#html_use_modindex = True
+# html_use_modindex = True
 
 # If false, no index is generated.
-#html_use_index = True
+# html_use_index = True
 
 # If true, the index is split into individual pages for each letter.
-#html_split_index = False
+# html_split_index = False
 
 # If true, links to the reST sources are added to the pages.
-#html_show_sourcelink = True
+# html_show_sourcelink = True
 
 # If true, an OpenSearch description file will be output, and all pages will
 # contain a <link> tag referring to it.  The value of this option must be the
 # base URL from which the finished HTML is served.
-#html_use_opensearch = ''
+# html_use_opensearch = ''
 
 # If nonempty, this is the file name suffix for HTML files (e.g. ".xhtml").
-#html_file_suffix = ''
+# html_file_suffix = ''
 
 # Output file base name for HTML help builder.
 htmlhelp_basename = 'cinderdoc'
@@ -219,10 +242,10 @@ htmlhelp_basename = 'cinderdoc'
 # -- Options for LaTeX output -------------------------------------------------
 
 # The paper size ('letter' or 'a4').
-#latex_paper_size = 'letter'
+# latex_paper_size = 'letter'
 
 # The font size ('10pt', '11pt' or '12pt').
-#latex_font_size = '10pt'
+# latex_font_size = '10pt'
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass
@@ -234,17 +257,17 @@ latex_documents = [
 
 # The name of an image file (relative to this directory) to place at the top of
 # the title page.
-#latex_logo = None
+# latex_logo = None
 
 # For "manual" documents, if this is true, then toplevel headings are parts,
 # not chapters.
-#latex_use_parts = False
+# latex_use_parts = False
 
 # Additional stuff for the LaTeX preamble.
-#latex_preamble = ''
+# latex_preamble = ''
 
 # Documents to append as an appendix to all manuals.
-#latex_appendices = []
+# latex_appendices = []
 
 # If false, no module index is generated.
-#latex_use_modindex = True
+# latex_use_modindex = True

tox.ini

@@ -127,7 +127,7 @@ commands = bandit -r cinder -n5 -x tests -ll
 # E251 unexpected spaces around keyword / parameter equals
 # reason: no improvement in readability
 ignore = E251
-exclude = .git,.venv,.tox,dist,tools,doc,*egg,build
+exclude = .git,.venv,.tox,dist,tools,doc/ext,*egg,build
 max-complexity=30
 
 [hacking]