Adding pre-commit

Introduced changes:
- pre-commit config and rules
- Add pre-commit to pep8 gate, Flake8 is covered in the pre-commit hooks.
- Applying fixes for pre-commit compliance in all code.

Also commit hash will be used instead of version tags in pre-commit to
prevend arbitrary code from running in developer's machines.

pre-commit will be used to:
- trailing whitespace;
- Replaces or checks mixed line ending (mixed-line-ending);
- Forbid files which have a UTF-8 byte-order marker (check-byte-order-marker);
- Checks that non-binary executables have a proper
  shebang (check-executables-have-shebangs);
- Check for files that contain merge conflict strings (check-merge-conflict);
- Check for debugger imports and py37+ breakpoint()
  calls in python source (debug-statements);
- Attempts to load all yaml files to verify syntax (check-yaml);
- Run flake8 checks (flake8) (local)

For further details about tests please refer to:
https://github.com/pre-commit/pre-commit-hooks

Change-Id: If4bd505d6bf73d06ce2f6080cedb3b5576c881d9
Signed-off-by: Moisés Guimarães de Medeiros <moguimar@redhat.com>

7 files changed, 80 insertions, 164 deletions

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..9d94556
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,35 @@
+# We from the Oslo project decided to pin repos based on the
+# commit hash instead of the version tag to prevend arbitrary
+# code from running in developer's machines.  To update to a
+# newer version, run `pre-commit autoupdate` and then replace
+# the newer versions with their commit hash.
+
+default_language_version:
+  python: python3
+
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: ebc15addedad713c86ef18ae9632c88e187dd0af  # v3.1.0
+    hooks:
+      - id: trailing-whitespace
+      # Replaces or checks mixed line ending
+      - id: mixed-line-ending
+        args: ['--fix', 'lf']
+        exclude: '.*\.(svg)$'
+      # Forbid files which have a UTF-8 byte-order marker
+      - id: check-byte-order-marker
+      # Checks that non-binary executables have a proper shebang
+      - id: check-executables-have-shebangs
+      # Check for files that contain merge conflict strings.
+      - id: check-merge-conflict
+      # Check for debugger imports and py37+ breakpoint()
+      # calls in python source
+      - id: debug-statements
+      - id: check-yaml
+        files: .*\.(yaml|yml)$
+  - repo: https://gitlab.com/pycqa/flake8
+    rev: 181bb46098dddf7e2d45319ea654b4b4d58c2840 # 3.8.3
+    hooks:
+      - id: flake8
+        additional_dependencies:
+          - hacking>=3.0.1,<3.1.0
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 67978eb..f904f7f 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -1,9 +1,23 @@
 # -*- coding: utf-8 -*-
+# Copyright (C) 2020 Red Hat, Inc.
+#
+# 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.
 #
 # OSprofiler documentation build configuration file, created by
 # sphinx-quickstart on Fri Jan 10 23:19:18 2014.
 #
-# This file is execfile()d with the current directory set to its containing dir.
+# This file is execfile()d with the current directory set to its
+# containing dir.
 #
 # Note that not all possible configuration values are present in this
 # autogenerated file.
@@ -14,21 +28,19 @@
 import os
 import sys
 
-# 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.
+# 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.
 sys.path.extend([
     os.path.abspath('../..'),
 ])
 
 
-# -- General configuration -----------------------------------------------------
+# -- General configuration ---------------------
 
-# If your documentation needs a minimal Sphinx version, state it here.
-#needs_sphinx = '1.0'
-
-# Add any Sphinx extension module names here, as strings. They can be extensions
-# coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
 extensions = [
     'sphinx.ext.autodoc',
     'sphinx.ext.doctest',
@@ -53,9 +65,6 @@ templates_path = ['_templates']
 # The suffix of source filenames.
 source_suffix = '.rst'
 
-# The encoding of source files.
-#source_encoding = 'utf-8-sig'
-
 # The master toctree document.
 master_doc = 'index'
 
@@ -63,23 +72,10 @@ master_doc = 'index'
 project = u'OSprofiler'
 copyright = u'2016, OpenStack Foundation'
 
-# The language for content autogenerated by Sphinx. Refer to documentation
-# for a list of supported languages.
-#language = None
-
-# There are two options for replacing |today|: either, you set today to some
-# non-false value, then it is used:
-#today = ''
-# Else, today_fmt is used as the format for a strftime call.
-#today_fmt = '%B %d, %Y'
-
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
 exclude_patterns = []
 
-# The reST default role (used for this markup: `text`) to use for all documents.
-#default_role = None
-
 # If true, '()' will be appended to :func: etc. cross-reference text.
 add_function_parentheses = True
 
@@ -87,108 +83,30 @@ add_function_parentheses = True
 # unit titles (such as .. function::).
 add_module_names = True
 
-# If true, sectionauthor and moduleauthor directives will be shown in the
-# output. They are ignored by default.
-#show_authors = False
-
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'native'
 
-# A list of ignored prefixes for module index sorting.
-#modindex_common_prefix = []
-
-
-# -- Options for HTML output ---------------------------------------------------
+# -- Options for HTML output ------------
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 html_theme = 'openstackdocs'
 
-# 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 = {}
-
-# Add any paths that contain custom themes here, relative to this directory.
-#html_theme_path = []
-
-# The name for this set of Sphinx documents.  If None, it defaults to
-# "<project> v<release> documentation".
-#html_title = None
-
-# A shorter title for the navigation bar.  Default is the same as html_title.
-#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
-
-# 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
-
 # 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,
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = []
 
-# If true, SmartyPants will be used to convert quotes and dashes to
-# typographically correct entities.
-#html_use_smartypants = True
-
-# Custom sidebar templates, maps document names to template names.
-#html_sidebars = {}
-
-# Additional templates that should be rendered to pages, maps page names to
-# template names.
-#html_additional_pages = {}
-
-# If false, no module index is generated.
-#html_domain_indices = True
-
-# If false, no index is generated.
-#html_use_index = True
-
-# If true, the index is split into individual pages for each letter.
-#html_split_index = False
-
-# If true, links to the reST sources are added to the pages.
-#html_show_sourcelink = True
-
-# If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
-#html_show_sphinx = True
-
-# If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
-#html_show_copyright = 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 = ''
-
-# This is the file name suffix for HTML files (e.g. ".xhtml").
-#html_file_suffix = None
-
 # Output file base name for HTML help builder.
 htmlhelp_basename = '%sdoc' % project
 
+# -- Options for LaTeX output --------------
 
-# -- Options for LaTeX output --------------------------------------------------
-
-latex_elements = {
-# The paper size ('letterpaper' or 'a4paper').
-#'papersize': 'letterpaper',
-
-# The font size ('10pt', '11pt' or '12pt').
-#'pointsize': '10pt',
-
-# Additional stuff for the LaTeX preamble.
-#'preamble': '',
-}
+latex_elements = {}
 
 # Grouping the document tree into LaTeX files. List of tuples
-# (source start file, target name, title, author, documentclass [howto/manual]).
+# (source start file, target name, title, author,
+# documentclass [howto/manual]).
 latex_documents = [
     ('index',
      '%s.tex' % project,
@@ -196,56 +114,19 @@ latex_documents = [
      u'OpenStack Foundation', 'manual'),
 ]
 
-# The name of an image file (relative to this directory) to place at the top of
-# the title page.
-#latex_logo = None
-
-# For "manual" documents, if this is true, then toplevel headings are parts,
-# not chapters.
-#latex_use_parts = False
-
-# If true, show page references after internal links.
-#latex_show_pagerefs = False
-
-# If true, show URL addresses after external links.
-#latex_show_urls = False
-
-# Documents to append as an appendix to all manuals.
-#latex_appendices = []
-
-# If false, no module index is generated.
-#latex_domain_indices = True
-
-
-# -- Options for manual page output --------------------------------------------
-
-# One entry per manual page. List of tuples
-# (source start file, name, description, authors, manual section).
-#man_pages = [
-#    ('index', 'rally', u'Rally Documentation',
-#     [u'Rally Team'], 1)
-#]
-
-# If true, show URL addresses after external links.
-#man_show_urls = False
-
-
-# -- Options for Texinfo output ------------------------------------------------
+# -- Options for Texinfo output -----------
 
 # Grouping the document tree into Texinfo files. List of tuples
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-  ('index', 'OSprofiler', u'OSprofiler Documentation',
-   u'OSprofiler Team', 'OSprofiler', 'One line description of project.',
-   'Miscellaneous'),
+    (
+        'index',
+        'OSprofiler',
+        u'OSprofiler Documentation',
+        u'OSprofiler Team',
+        'OSprofiler',
+        'One line description of project.',
+        'Miscellaneous'
+    ),
 ]
-
-# Documents to append as an appendix to all manuals.
-#texinfo_appendices = []
-
-# If false, no module index is generated.
-#texinfo_domain_indices = True
-
-# How to display URL addresses: 'footnote', 'no', or 'inline'.
-#texinfo_show_urls = 'footnote'
diff --git a/osprofiler/tests/unit/doc/test_specs.py b/osprofiler/tests/unit/doc/test_specs.py
index fe2b867..e875227 100644
--- a/osprofiler/tests/unit/doc/test_specs.py
+++ b/osprofiler/tests/unit/doc/test_specs.py
@@ -74,7 +74,7 @@ class TitlesTestCase(test.TestCase):
             self.assertTrue(
                 len(line) < 80,
                 msg="%s:%d: Line limited to a maximum of 79 characters." %
-                (tpl, i+1))
+                (tpl, i + 1))
 
     def _check_no_cr(self, tpl, raw):
         matches = re.findall("\r", raw)
@@ -88,7 +88,7 @@ class TitlesTestCase(test.TestCase):
             trailing_spaces = re.findall(" +$", line)
             self.assertEqual(
                 len(trailing_spaces), 0,
-                "Found trailing spaces on line %s of %s" % (i+1, tpl))
+                "Found trailing spaces on line %s of %s" % (i + 1, tpl))
 
     def test_template(self):
         with open(os.path.join(self.specs_path, "template.rst")) as f:
diff --git a/test-requirements.txt b/test-requirements.txt
index a227fe4..a2ca153 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -25,3 +25,5 @@ reno>=3.1.0 # Apache-2.0
 
 # For Jaeger Tracing
 jaeger-client>=3.8.0 # Apache-2.0
+
+pre-commit>=2.6.0 # MIT
diff --git a/tools/lint.py b/tools/lint.py
index d2a545b..62864eb 100644
--- a/tools/lint.py
+++ b/tools/lint.py
@@ -12,9 +12,6 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
-#
-# @author: Zhongyue Luo, Intel Corporation.
-#
 
 import sys
 
@@ -28,5 +25,6 @@ def main(dirpath):
     enable_opt = '--enable=%s' % ','.join(ENABLED_PYLINT_MSGS)
     lint.Run(['--reports=n', '--disable=all', enable_opt, dirpath])
 
+
 if __name__ == '__main__':
     main(sys.argv[1])
diff --git a/tools/patch_tox_venv.py b/tools/patch_tox_venv.py
index ee8f53c..52b724c 100644
--- a/tools/patch_tox_venv.py
+++ b/tools/patch_tox_venv.py
@@ -41,8 +41,9 @@ def main(argv):
     project = 'oslo'
     install = install_venv.InstallVenv(root, venv, pip_requires, test_requires,
                                        py_version, project)
-    #NOTE(dprince): For Tox we only run post_process (which patches files, etc)
+    # NOTE(dprince): For Tox we only run post_process, which patches files, etc
     install.post_process()
 
+
 if __name__ == '__main__':
     main(sys.argv)
diff --git a/tox.ini b/tox.ini
index 112fd78..0c34eba 100644
--- a/tox.ini
+++ b/tox.ini
@@ -34,7 +34,7 @@ deps =
 
 [testenv:pep8]
 commands =
-  flake8
+  pre-commit run -a
   # Run security linter
   bandit -r osprofiler -n5
 distribute = false
@@ -76,7 +76,6 @@ extension =
     N322 = checks:assert_equal_none
     N323 = checks:assert_true_or_false_with_in
     N324 = checks:assert_equal_in
-    N350 = checks:check_quotes
     N351 = checks:check_no_constructor_data_struct
     N352 = checks:check_dict_formatting_in_string
     N353 = checks:check_using_unicode