fix tox python3 overrides

We want to default to running all tox environments under python 3, so
set the basepython value in each environment.

We do not want to specify a minor version number, because we do not
want to have to update the file every time we upgrade python.

We do not want to set the override once in testenv, because that
breaks the more specific versions used in default environments like
py35 and py36.

Change-Id: Ic9645685e0f9ae25b0b2b754b11e34d8aef41829
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

tox.ini

@@ -5,7 +5,6 @@ skipsdist = True
 
 [testenv]
 # Set default python version
-basepython = python2.7
 setenv =
   VIRTUAL_ENV={envdir}
   PYTHONWARNINGS=default::DeprecationWarning
@@ -64,6 +63,7 @@ commands =
   stestr run --whitelist-file ./broken-functional-py35-ssl-tests.txt {posargs}
 
 [testenv:pep8]
+basepython = python3
 commands =
   flake8 {posargs}
   # Run security linter
@@ -73,6 +73,7 @@ commands =
   doc8 {posargs}
 
 [testenv:genconfig]
+basepython = python3
 commands =
   oslo-config-generator --config-file etc/oslo-config-generator/glance-api.conf
   oslo-config-generator --config-file etc/oslo-config-generator/glance-registry.conf
@@ -82,6 +83,7 @@ commands =
   oslo-config-generator --config-file etc/oslo-config-generator/glance-image-import.conf
 
 [testenv:api-ref]
+basepython = python3
 # This environment is called from CI scripts to test and publish
 # the API Ref to developer.openstack.org.
 deps =
@@ -92,6 +94,7 @@ commands =
   sphinx-build -W -b html -d api-ref/build/doctrees api-ref/source api-ref/build/html
 
 [testenv:bindep]
+basepython = python3
 # Do not install any requirements. We want this to be fast and work even if
 # system dependencies are missing, since it's used to tell you what system
 # dependencies are missing! This also means that bindep must be installed
@@ -119,6 +122,7 @@ local-check-factory = glance.hacking.checks.factory
 import_exceptions = glance.i18n
 
 [testenv:docs]
+basepython = python3
 deps =
     -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
     -r{toxinidir}/doc/requirements.txt
@@ -128,12 +132,15 @@ commands =
   whereto doc/source/_extra/.htaccess doc/test/redirect-tests.txt
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:bandit]
+basepython = python3
 commands = bandit -c bandit.yaml -r glance -n5 -p gate
 
 [testenv:releasenotes]
+basepython = python3
 deps =
     -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
     -r{toxinidir}/doc/requirements.txt
@@ -141,6 +148,7 @@ commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:cover]
+basepython = python3
 setenv =
     PYTHON=coverage run --source glance --parallel-mode
 commands =
@@ -150,6 +158,7 @@ commands =
     coverage xml -o cover/coverage.xml
 
 [testenv:debug]
+basepython = python3
 commands =
   oslo_debug_helper {posargs}