Fix pifpaf not returning error code upon test failure

For whatever reason, the following command:

   pifpaf run postgresql -- <test command>

is not returning a non-zero error code on test failure.

(An example print out is included below.)

This PS updates pretty_tox.sh to forcibly raise a non-zero error
code in the event of test failure. It also renames the script
to run_pifpaf.sh to be more intuitive.

Example:

======
Totals
======
Ran: 7 tests in 5.7673 sec.
 - Passed: 6
 - Skipped: 0
 - Expected Fail: 0
 - Unexpected Success: 0
 - Failed: 1
Sum of execute time for each test: 2.6962 sec.

==============
Worker Balance
==============
 - Worker 0 (7 tests) => 0:00:02.698323
+ exit 0

  py35: commands succeeded
  congratulations :)

Change-Id: I7b1fa9d42295d06752997f251a0ec14082b44d03

tools/pretty_tox.sh

@@ -1,16 +0,0 @@
-#!/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

tools/run_pifpaf.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+# This script is used for guaranteeing that `pifpaf` returns non-zero codes
+# upon test failure.
+
+function cleanup {
+    pifpaf_stop
+}
+
+trap cleanup EXIT
+
+# Instantiate an ephemeral PostgreSQL DB and print out the `pifpaf` environment
+# variables for debugging purposes.
+set -ex
+eval `pifpaf run postgresql`
+env | grep PIFPAF
+set +ex
+
+set -eo pipefail
+
+TESTRARGS=$1
+
+python setup.py testr --slowest --testr-args="--subunit --concurrency=1 $TESTRARGS" | subunit-trace -f

tox.ini

@@ -21,12 +21,12 @@ commands =
 [testenv:py27]
 commands =
     {[testenv]commands}
-    pifpaf run postgresql -- '{toxinidir}'/tools/pretty_tox.sh '--concurrency=1 {posargs}'
+    {toxinidir}/tools/run_pifpaf.sh '{posargs}'
 
 [testenv:py35]
 commands =
     {[testenv]commands}
-    pifpaf run postgresql -- '{toxinidir}'/tools/pretty_tox.sh '--concurrency=1 {posargs}'
+    {toxinidir}/tools/run_pifpaf.sh '{posargs}'
 
 [testenv:functional]
 usedevelop = True