tox: Slight tweaks

- Use 'ignore_basepython_conflict' and set 'basepython' globally,
  avoiding the need to do it in each environment
- Set 'commands' in the top-level 'testenv' and just reference this
  where needed
- Remove unneeded 'setenv'

Change-Id: Ib2ac6279abf5cf3fa39cb1b72622e41c502429b5
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

tox.ini

@@ -1,10 +1,14 @@
 [tox]
-envlist = pep8,py27,py36,py37,py3-dj111,releasenotes,npm
-minversion = 2.5.0
+minversion = 3.1
+envlist = pep8,py27,py36,py37,py3-dj{111,21,22},releasenotes,npm
 skipsdist = True
+# Automatic envs (pyXX) will only use the python version appropriate to that
+# env and ignore basepython inherited from [testenv] if we set
+# ignore_basepython_conflict.
+ignore_basepython_conflict = True
 
 [testenv]
-install_command = pip install {opts} {packages}
+basepython = python3
 usedevelop = True
 setenv =
   VIRTUAL_ENV={envdir}
@@ -15,52 +19,29 @@ deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
-commands = {[unit_tests]commands}
-
-[unit_tests]
 commands =
-    find . -type f -name "*.pyc" -delete
-    bash {toxinidir}/tools/unit_tests.sh {envpython} {toxinidir} {posargs}
-
-[testenv:py3-dj21]
-basepython = python3
-commands =
-  pip install django>=2.1<2.2
-  {[unit_tests]commands}
-
-[testenv:py3-dj22]
-basepython = python3
-commands =
-  pip install django>=2.2<2.3
-  {[unit_tests]commands}
-
-
-[testenv:py3-dj111]
-basepython = python3
-commands =
-  pip install django>=1.11,<2
-  {[unit_tests]commands}
+  dj111: pip install django>=1.11,<2.0
+  dj21: pip install django>=2.1,<2.2
+  dj22: pip install django>=2.2,<2.3
+  find . -type f -name "*.pyc" -delete
+  bash {toxinidir}/tools/unit_tests.sh {envpython} {toxinidir} {posargs}
 
 [testenv:lower-constraints]
-basepython = python3
 deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [testenv:pep8]
-basepython = python3
 # NOTE: Due to doc dependencies, we don't share envdir with "venv".
 # sphinx (precisely Pygments) needs to be installed to make doc8 work properly
 deps =
   {[testenv]deps}
   -r{toxinidir}/doc/requirements.txt
 setenv =
-  {[testenv]setenv}
   DJANGO_SETTINGS_MODULE=openstack_dashboard.test.settings
 commands =
   flake8 {posargs}
@@ -70,7 +51,6 @@ commands =
   pylint -j 4 --verbose --rcfile=.pylintrc -f colorized openstack_dashboard openstack_auth horizon
 
 [testenv:cover]
-basepython = python3
 envdir = {toxworkdir}/venv
 commands =
   coverage erase
@@ -81,36 +61,29 @@ commands =
   coverage html
 
 [testenv:selenium]
-basepython = python3
 envdir = {toxworkdir}/venv
 setenv =
   {[testenv]setenv}
   WITH_SELENIUM=1
   SKIP_UNITTESTS=1
-commands = {[unit_tests]commands}
 
 [testenv:selenium-headless]
-basepython = python3
 envdir = {toxworkdir}/venv
 setenv =
   {[testenv]setenv}
   SELENIUM_HEADLESS=1
   WITH_SELENIUM=1
   SKIP_UNITTESTS=1
-commands = {[unit_tests]commands}
 
 [testenv:selenium-phantomjs]
-basepython = python3
 envdir = {toxworkdir}/venv
 setenv =
   {[testenv]setenv}
   SELENIUM_PHANTOMJS=1
   WITH_SELENIUM=1
   SKIP_UNITTESTS=1
-commands = {[unit_tests]commands}
 
 [testenv:integration]
-basepython = python3
 envdir = {toxworkdir}/venv
 # Run integration tests only
 passenv = AVCONV_INSTALLED
@@ -121,7 +94,6 @@ setenv =
 commands = {envpython} {toxinidir}/manage.py test openstack_dashboard --settings=openstack_dashboard.test.settings --verbosity 2 --tag integration {posargs}
 
 [testenv:npm]
-basepython = python3
 passenv =
   HOME
   DISPLAY
@@ -131,7 +103,6 @@ commands =
   npm run {posargs:test}
 
 [testenv:tests_system_packages]
-basepython = python3
 # Provide an environment for system packagers that dont want anything from pip
 # Any extra deps needed for this env can be passed by setting TOX_EXTRA_DEPS
 sitepackages = True
@@ -140,10 +111,9 @@ passenv = TOX_EXTRA_DEPS http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy
 deps =
 commands =
   pip install -U {env:TOX_EXTRA_DEPS:}
-  {[unit_tests]commands}
+  {[testenv]commands}
 
 [testenv:docs]
-basepython = python3
 # We need to install horizon dependecies to build module references
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
@@ -153,19 +123,16 @@ commands =
   sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:releasenotes]
-basepython = python3
 envdir = {toxworkdir}/docs
 deps = {[testenv:docs]deps}
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:manage]
-basepython = python3
 envdir = {toxworkdir}/venv
 commands = {envpython} {toxinidir}/manage.py {posargs}
 
 [testenv:runserver]
-basepython = python3
 envdir = {toxworkdir}/venv
 commands =
     {envpython} {toxinidir}/manage.py compilemessages
@@ -173,13 +140,11 @@ commands =
     {envpython} {toxinidir}/manage.py runserver {posargs}
 
 [testenv:bandit]
-basepython = python3
 envdir = {toxworkdir}/venv
 commands = bandit -r horizon openstack_auth openstack_dashboard -n5 -x tests -ll
 
 [testenv:bandit-baseline]
 envdir = {toxworkdir}/venv
-basepython = python3
 commands = bandit-baseline -r horizon  openstack_auth openstack_dashboard -n5 -x tests -ii -ll
 
 [flake8]