Fix tox.ini misconfigurations

Previous setup introduce several problems because pre-commit was never run with
all configured hooks. New setup does not require any changes to tox.ini when
new linters/hooks are added.

- openstack-tox-pep8 removed, replaced by generic linters
- fixed bug where CI did not run all linters, mainly because of tox.ini env layout
- kept only one linters environment with its sole requirement
- saved considerable amount of time wasted installing unused dependencies
- moved doc8 config to setup.cfg (standard location)

Change-Id: Idda6418ea1dcc3877e078f3cd9c59631fcc2ec68

setup.cfg

@@ -50,3 +50,8 @@ skip_changelog = True
 # based on https://github.com/psf/black
 ignore = E203,E501,W503,W504,D
 # "D" added because we do not use docstrings checks, yet
+
+[doc8]
+# Settings for doc8:
+extensions = .rst
+ignore = D001

test-requirements.txt

@@ -1,4 +1,3 @@
-pre-commit # MIT
 netaddr # BSD
 mock>=2.0.0 # BSD
 stestr>=2.0.0 # Apache-2.0

tox.ini

@@ -42,55 +42,21 @@ whitelist_externals =
 deps = bindep
 commands = bindep test
 
+[testenv:linters]
+description =
+    Runs all linters, if you want to run a single one, use posargs to mention
+    it. Example `tox -e linters -- ansible-lint`
+deps =
+   pre-commit>=1.20  # MIT
+commands =
+    python -m pre_commit run -a {posargs}
+
+# Use 'linters' instead, kept only for compatibility with:
+# https://opendev.org/openstack/openstack-zuul-jobs/src/branch/master/zuul.d/project-templates.yaml#L459
 [testenv:pep8]
 envdir = {toxworkdir}/linters
-commands =
-    python -m pre_commit run flake8 -a
-
-[testenv:ansible-lint]
-envdir = {toxworkdir}/linters
-deps =
-  {[testenv:linters]deps}
-commands =
-  python -m pre_commit run ansible-lint -a
-#  bash -c "ANSIBLE_ROLES_PATH='{toxinidir}/roles' \
-#           ansible-galaxy install -fr {toxinidir}/ansible-role-requirements.yml"
-
-[testenv:yamllint]
-envdir = {toxworkdir}/linters
 deps =  {[testenv:linters]deps}
-commands =
-    python -m pre_commit run yamllint -a
-
-[testenv:bashate]
-envdir = {toxworkdir}/linters
-deps = {[testenv:linters]deps}
-commands =
-    python -m pre_commit run bashate -a
-
-[testenv:whitespace]
-envdir = {toxworkdir}/linters
-deps = {[testenv:linters]deps}
-commands =
-    python -m pre_commit run trailing-whitespace -a
-
-[testenv:shebangs]
-envdir = {toxworkdir}/linters
-deps = {[testenv:linters]deps}
-commands =
-    python -m pre_commit run check-executables-have-shebangs -a
-
-[testenv:linters]
-deps =
-    -r {toxinidir}/requirements.txt
-    -r {toxinidir}/test-requirements.txt
-commands =
-    {[testenv:pep8]commands}
-    {[testenv:ansible-lint]commands}
-    {[testenv:bashate]commands}
-    {[testenv:yamllint]commands}
-    {[testenv:whitespace]commands}
-    {[testenv:shebangs]commands}
+commands =  {[testenv:linters]commands}
 
 [testenv:releasenotes]
 basepython = python3
@@ -106,11 +72,6 @@ commands=
     doc8 doc
     sphinx-build -a -E -W -d doc/build/doctrees --keep-going -b html doc/source doc/build/html -T
 
-[doc8]
-# Settings for doc8:
-extensions = .rst
-ignore = D001
-
 [testenv:venv]
 commands = {posargs}
 
@@ -140,3 +101,5 @@ deps =
     oslotest
 commands =
     python -m pytest -ra --continue-on-collection-errors -v --color=yes --html={envlogdir}/reports.html --self-contained-html {tty:-s} -k {posargs}
+
+# do not put tool config in tox.ini, use setup.cfg or tool specific files