Allow tox to pass more arguments to ostestr command

Co-Authored-By: Kevin Benton <blak111@gmail.com>
Change-Id: Ie9969e0a5254ab5dd33b287f6d3120362b73edd7
Closes-bug: #1490389

TESTING.rst

@@ -298,6 +298,10 @@ or::
       $ tox -e py27 neutron.tests.unit.test_manager.NeutronManagerTestCase
       $ tox -e py27 neutron.tests.unit.test_manager.NeutronManagerTestCase.test_service_plugin_is_loaded
 
+If you want to pass other arguments to ostestr, you can do the following::
+      $ tox -e -epy27 -- --regex neutron.tests.unit.test_manager --serial
+
+
 Coverage
 --------
 

tools/ostestr_compat_shim.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+# preserve old behavior of using an arg as a regex when '--' is not present
+case $@ in
+  (*--*) ostestr $@;;
+  ('') ostestr;;
+  (*) ostestr --regex "$@"
+esac

tox.ini

@@ -13,7 +13,7 @@ deps = -r{toxinidir}/requirements.txt
 whitelist_externals = sh
 commands =
   dsvm-functional: {toxinidir}/tools/deploy_rootwrap.sh {toxinidir} {envdir}/etc {envdir}/bin
-  ostestr --regex '{posargs}'
+  {toxinidir}/tools/ostestr_compat_shim.sh {posargs}
 # there is also secret magic in ostestr which lets you run in a fail only
 # mode. To do this define the TRACE_FAILONLY environmental variable.