Check the number of tests that were run after tox before success

This adds a dirty check of the output file after a tox run to make
sure that at least one test passed. If not, then we shouldn't
allow a successful result. This is intended to catch the case where
none of the tests run because of some parse or test setup error,
which might otherwise be considered a successful run.

Change-Id: I598262f47971e238876b38416c00a70de8313543
Reviewed-on: https://review.openstack.org/14402
Reviewed-by: Monty Taylor <mordred@inaugust.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins

modules/jenkins/files/slave_scripts/run-tox.sh

@@ -63,4 +63,23 @@ then
     exit 1
 fi
 
+htmlreport=$(find . -name $NOSE_HTML_OUT_FILE)
+if [ -f "$htmlreport" ]
+then
+    passcount=$(grep -c 'tr class=.passClass' $htmlreport)
+    if [ $passcount -eq "0" ]
+    then
+        echo
+        echo "Zero tests passed, which probably means there was an error"
+        echo "parsing one of the python files, or that some other failure"
+        echo "during test setup prevented a sane run."
+        echo
+        exit 1
+    fi
+else
+    echo
+    echo "WARNING: Unable to find $NOST_HTML_OUT_FILE to confirm results!"
+    echo
+fi
+
 exit $result