Drop python 2.7 support and testing

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

glance_store is ready with python 3 and ok to drop the
python 2.7 support.

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://review.opendev.org/#/c/691178/

Change-Id: I6166a20610f77e0df7da75198e0c8273bb121d1f

.zuul.yaml

@@ -12,6 +12,7 @@
     vars:
       devstack_localrc:
         LIBS_FROM_GIT: glance_store
+        USE_PYTHON3: True
       devstack_services:
         # turn off ceilometer
         ceilometer-acentral: false
@@ -54,14 +55,6 @@
       - name: openstack/os-brick
       - name: openstack/python-cinderclient
 
-- job:
-    name: glance_store-tox-py27-cinder-tips
-    parent: glance_store-tox-cinder-tips-base
-    description: |
-      glance_store py27 unit tests vs. cinder masters
-    vars:
-      tox_envlist: py27
-
 - job:
     name: glance_store-tox-py36-cinder-tips
     parent: glance_store-tox-cinder-tips-base
@@ -79,14 +72,6 @@
       - name: openstack/keystoneauth
       - name: openstack/python-keystoneclient
 
-- job:
-    name: glance_store-tox-py27-keystone-tips
-    parent: glance_store-tox-keystone-tips-base
-    description: |
-      glance_store py27 unit tests vs. keystone masters
-    vars:
-      tox_envlist: py27
-
 - job:
     name: glance_store-tox-py36-keystone-tips
     parent: glance_store-tox-keystone-tips-base
@@ -111,14 +96,6 @@
       - name: openstack/oslo.vmware
       - name: openstack/stevedore
 
-- job:
-    name: glance_store-tox-py27-oslo-tips
-    parent: glance_store-tox-oslo-tips-base
-    description: |
-      glance_store py27 unit tests vs. oslo masters
-    vars:
-      tox_envlist: py27
-
 - job:
     name: glance_store-tox-py36-oslo-tips
     parent: glance_store-tox-oslo-tips-base
@@ -135,14 +112,6 @@
     required-projects:
       - name: openstack/python-swiftclient
 
-- job:
-    name: glance_store-tox-py27-swift-tips
-    parent: glance_store-tox-swift-tips-base
-    description: |
-      glance_store py27 unit tests vs. swift masters
-    vars:
-      tox_envlist: py27
-
 - job:
     name: glance_store-tox-py36-swift-tips
     parent: glance_store-tox-swift-tips-base
@@ -157,8 +126,7 @@
       - lib-forward-testing
       - lib-forward-testing-python3
       - openstack-lower-constraints-jobs
-      - openstack-python-jobs
-      - openstack-python3-train-jobs
+      - openstack-python3-ussuri-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3
     check:
@@ -192,19 +160,11 @@
         # to define these jobs in the openstack/project-config repo.
         # That would make us less agile in adjusting these tests, so we
         # aren't doing that either.
-        - glance_store-tox-py27-cinder-tips:
-            branches: master
         - glance_store-tox-py36-cinder-tips:
             branches: master
-        - glance_store-tox-py27-keystone-tips:
-            branches: master
         - glance_store-tox-py36-keystone-tips:
             branches: master
-        - glance_store-tox-py27-oslo-tips:
-            branches: master
         - glance_store-tox-py36-oslo-tips:
             branches: master
-        - glance_store-tox-py27-swift-tips:
-            branches: master
         - glance_store-tox-py36-swift-tips:
             branches: master

releasenotes/notes/drop-py-2-7-345cafc9c1d3f892.yaml

@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    Python 2.7 support has been dropped. Last release of glance_store
+    to support py2.7 is OpenStack Train. The minimum version of Python now
+    supported by glance_store is Python 3.6.

setup.cfg

@@ -14,8 +14,6 @@ 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

tox.ini

@@ -1,9 +1,11 @@
 [tox]
-minversion = 1.6
-envlist = py27,py37,pep8
+minversion = 3.1.1
+envlist = py37,py36,pep8
 skipsdist = True
+ignore_basepython_conflict = True
 
 [testenv]
+basepython = python3
 setenv = VIRTUAL_ENV={envdir}
 usedevelop = True
 deps =
@@ -14,23 +16,19 @@ passenv = OS_TEST_*
 commands = stestr run --slowest {posargs}
 
 [testenv:docs]
-basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:releasenotes]
-basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -a -E -W -d releasenotes/build/.doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:pep8]
-basepython = python3
 commands =
   flake8 {posargs}
   doc8 {posargs}
 
 [testenv:cover]
-basepython = python3
 setenv =
     PYTHON=coverage run --source glance_store --parallel-mode
 commands =
@@ -40,7 +38,6 @@ commands =
     coverage xml -o cover/coverage.xml
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 # See glance_store/tests/functional/README.rst for information on writing or
@@ -66,7 +63,6 @@ ignore = H301,H404,H405
 exclude = .venv,.git,.tox,dist,doc,etc,*glance_store/locale*,*lib/python*,*egg,build
 
 [testenv:lower-constraints]
-basepython = python3
 deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt