add pretty_tox to nova functional tests

debugging tests is a lot easier when you can actually inject stderr
directly through even on successes. Add the pretty tox facility from
nova / tempest-lib into python-nova client as well for functional
tests.

Change-Id: I5c1f8244a5c743b590b74a8eb3eaf4a699555644

tools/pretty_tox.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+set -o pipefail
+
+TESTRARGS=$1
+
+# --until-failure is not compatible with --subunit see:
+#
+# https://bugs.launchpad.net/testrepository/+bug/1411804
+#
+# this work around exists until that is addressed
+if [[ "$TESTARGS" =~ "until-failure" ]]; then
+    python setup.py testr --slowest --testr-args="$TESTRARGS"
+else
+    python setup.py testr --slowest --testr-args="--subunit $TESTRARGS" | subunit-trace -f
+fi

tox.ini

@@ -8,6 +8,7 @@ skipsdist = True
 usedevelop = True
 # tox is silly... these need to be separated by a newline....
 whitelist_externals = find
+                    bash
 install_command = pip install -U {opts} {packages}
 setenv = VIRTUAL_ENV={envdir}
 
@@ -15,7 +16,9 @@ deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands =
   find . -type f -name "*.pyc" -delete
-  python setup.py testr --testr-args='{posargs}'
+  bash tools/pretty_tox.sh '{posargs}'
+  # there is also secret magic in pretty_tox.sh which lets you run in a fail only
+  # mode. To do this define the TRACE_FAILONLY environmental variable.
 
 [testenv:pep8]
 commands = flake8 {posargs}