[ussuri][goal] Drop python 2.7 support and testing

OpenStack is dropping the py2.7 support in ussuri cycle.

Complete discussion & schedule can be found in
- http://lists.openstack.org/pipermail/openstack-discuss/2019-October/010142.html
- https://etherpad.openstack.org/p/drop-python2-support

Ussuri Communtiy-wide goal:
https://governance.openstack.org/tc/goals/selected/ussuri/drop-py27.html

Cleanup tox.ini and setup.cfg from old cruft, use sphinx-build.

Change-Id: I395558c888d31925c26571f62ffc1ea556f2e2c4
Co-Authored-By: Hervé Beraud <hberaud@redhat.com>

.zuul.yaml

@@ -1,10 +1,8 @@
 - project:
     templates:
       - check-requirements
-      - lib-forward-testing
       - lib-forward-testing-python3
       - openstack-lower-constraints-jobs
-      - openstack-python-jobs
       - openstack-python3-train-jobs
       - periodic-stable-jobs
       - publish-openstack-docs-pti

lower-constraints.txt

@@ -8,7 +8,6 @@ dulwich==0.15.0
 extras==1.0.0
 fixtures==3.0.0
 flake8==2.2.4
-funcsigs==1.0.0
 hacking==0.10.3
 imagesize==0.7.1
 Jinja2==2.10

releasenotes/notes/drop-python-2-7-73d3113c69d724d6.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - |
+    Python 2.7 support has been dropped. The minimum version of Python now
+    supported by debtcollector is Python 3.6.

requirements.txt

@@ -5,4 +5,3 @@
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 six>=1.10.0 # MIT
 wrapt>=1.7.0 # BSD License
-funcsigs>=1.0.0;python_version=='2.7' or python_version=='2.6' # Apache-2.0

setup.cfg

@@ -6,6 +6,7 @@ description-file =
 author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 home-page =  https://docs.openstack.org/debtcollector/latest
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -13,24 +14,12 @@ classifier =
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
     Programming Language :: Python
-    Programming Language :: Python :: 2
-    Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3 :: Only
+    Programming Language :: Python :: Implementation :: CPython
 
 [files]
 packages =
     debtcollector
-
-[build_sphinx]
-source-dir = doc/source
-build-dir = doc/build
-all_files = 1
-warning-is-error = 1
-
-[upload_sphinx]
-upload-dir = doc/build/html
-
-[wheel]
-universal = 1

setup.py

@@ -16,14 +16,6 @@
 # THIS FILE IS MANAGED BY THE GLOBAL REQUIREMENTS REPO - DO NOT EDIT
 import setuptools
 
-# In python < 2.7.4, a lazy loading of package `pbr` will break
-# setuptools if some other modules registered functions in `atexit`.
-# solution from: http://bugs.python.org/issue15881#msg170215
-try:
-    import multiprocessing  # noqa
-except ImportError:
-    pass
-
 setuptools.setup(
     setup_requires=['pbr>=2.0.0'],
     pbr=True)

test-requirements.txt

@@ -6,8 +6,7 @@ hacking<0.11,>=0.10.0
 
 coverage!=4.4,>=4.0 # Apache-2.0
 python-subunit>=1.0.0 # Apache-2.0/BSD
-sphinx!=1.6.6,!=1.6.7,>=1.6.5,<2.0.0;python_version=='2.7' # BSD
-sphinx!=1.6.6,!=1.6.7,>=1.6.5;python_version>='3.4' # BSD
+sphinx!=1.6.6,!=1.6.7,>=1.6.5 # BSD
 openstackdocstheme>=1.18.1 # Apache-2.0
 stestr>=2.0.0 # Apache-2.0
 testtools>=2.2.0 # MIT

tox.ini

@@ -1,37 +1,31 @@
 [tox]
-minversion = 2.0
-envlist = py27,py37,pep8
+minversion = 3.1.1
+envlist = py37,pep8
+ignore_basepython_conflict = True
 
 [testenv]
+basepython = python3
 setenv =
     VIRTUAL_ENV={envdir}
-    BRANCH_NAME=master
-    CLIENT_NAME=debtcollector
-install_command = pip install {opts} {packages}
 deps =
  -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
  -r{toxinidir}/test-requirements.txt
  -r{toxinidir}/requirements.txt
-commands = stestr run --slowest {posargs}
+commands =
+    stestr run --slowest {posargs}
+    sphinx-build -b doctest doc/source doc/build
+    doc8 --ignore-path "doc/source/history.rst" doc/source
 
 [testenv:debug]
-basepython = python3
-commands = oslo_debug_helper {posargs}
-
-[testenv:debug-py27]
-basepython = python2.7
 commands = oslo_debug_helper {posargs}
 
 [testenv:pep8]
-basepython = python3
 commands = flake8
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [testenv:cover]
-basepython = python3
 setenv =
     PYTHON=coverage run --source $project --parallel-mode
 commands =
@@ -41,15 +35,7 @@ commands =
     coverage xml -o cover/coverage.xml
 
 [testenv:docs]
-basepython = python3
-commands = python setup.py build_sphinx
-
-[testenv:py27]
-basepython = python2.7
-commands =
-    stestr run --slowest {posargs}
-    sphinx-build -b doctest doc/source doc/build
-    doc8 --ignore-path "doc/source/history.rst" doc/source
+commands = sphinx-build -W --keep-going -b html -d doc/build/doctrees doc/source doc/build/html
 
 [flake8]
 # E123, E125 skipped as they are invalid PEP-8.
@@ -58,11 +44,9 @@ ignore = E123,E125
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 
 [testenv:releasenotes]
-basepython = python3
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:lower-constraints]
-basepython = python3
 deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt