Switch to newer openstackdocstheme and reno versions

Switch to openstackdocstheme 2.2.1 and reno 3.1.0 versions. Using
these versions will allow especially:
* Linking from HTML to PDF document
* Allow parallel building of documents
* Fix some rendering problems

Update Sphinx version as well.

Set openstackdocs_pdf_link to link to PDF file. Note that
the link to the published document only works on docs.openstack.org
where the PDF file is placed in the top-level html directory. The
site-preview places the PDF in a pdf directory.

Disable openstackdocs_auto_name to use 'project' variable as name.

Change pygments_style to 'native' since old theme version always used
'native' and the theme now respects the setting and using 'sphinx' can
lead to some strange rendering.

openstackdocstheme renames some variables, so follow the renames
before the next release removes them. A couple of variables are also
not needed anymore, remove them.

See also
http://lists.openstack.org/pipermail/openstack-discuss/2020-May/014971.html

Change-Id: Ieaaff8278e93f85bd711a340f9621ae18841e720

2 files changed, 9 insertions, 12 deletions

diff --git a/doc/requirements.txt b/doc/requirements.txt
index 598dd8aa..a5a208c9 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,6 +1,6 @@
-sphinx!=1.6.6,!=1.6.7,>=1.6.2  # BSD
+sphinx>=2.0.0,!=2.1.0 # BSD
 sphinxcontrib-httpdomain>=1.3.0 # BSD
 sphinxcontrib-blockdiag>=1.5.4 # BSD
-reno>=2.5.0 # Apache-2.0
+reno>=3.1.0 # Apache-2.0
 os-api-ref>=1.4.0 # Apache-2.0
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=2.2.1 # Apache-2.0
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 51bcb90e..b1b610b7 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -93,7 +93,7 @@ exclude_patterns = ['**/#*', '**~', '**/#*#']
 show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = 'sphinx'
+pygments_style = 'native'
 
 # A list of ignored prefixes for module index sorting.
 #modindex_common_prefix = []
@@ -111,9 +111,11 @@ nitpicky = False
 html_theme = 'openstackdocs'
 
 # openstackdocstheme options
-repository_name = 'openstack/ceilometer'
-bug_project = 'ceilometer'
-bug_tag = ''
+openstackdocs_repo_name = 'openstack/ceilometer'
+openstackdocs_pdf_link = True
+openstackdocs_auto_name = False
+openstackdocs_bug_project = 'ceilometer'
+openstackdocs_bug_tag = ''
 
 # Add any paths that contain custom themes here, relative to this directory.
 #html_theme_path = []
@@ -139,11 +141,6 @@ bug_tag = ''
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
 
-# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
-# using the given strftime format.
-# Must set this variable to include year, month, day, hours, and minutes.
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
-
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
 #html_use_smartypants = True