Add a tempestrunrc for configuring run-tempest

Add a tempestrunrc file which is sourced by run-tempest
to get input settings such as image-name and concurrency.

Variables in tempestrunrc can be via the ExtraConfig of
the image where the element is deployed.

Change-Id: I24b04b22e911732ffb9884a15cc45afabc02100a

elements/tempest/README.md

@@ -10,7 +10,10 @@ To successfully run tempest your overcloud should have
 To use you should simply run the command run-tempest with the
 OS_* environment variables for admin defined.
 
+Tempest configuration may be overwritten via pass-through.
+tempest-run configuration is defined in etc/tempestrunrc; values in there
+may be overwritten using ExtraConfig.
+
 TODO:
 * Remove as many of the filters in tests2skip.txt as possible
-* Investigate setting allow_tenant_isolation to true
 * Investigate setting run_ssh to true

elements/tempest/bin/run-tempest

@@ -18,9 +18,15 @@
 set -eux
 set -o pipefail
 
-# Setup the environment
-TEMPEST_RUN_CONCURRENCY=${TEMPEST_RUN_CONCURRENCY:-0}
-TEMPEST_IMAGE_NAME=${TEMPEST_IMAGE_NAME:-user}
+function check_environment {
+    # Check the environment to fail nicely if something is missing
+    TEMPEST_RUN_CONCURRENCY=${TEMPEST_RUN_CONCURRENCY:?"TEMPEST_RUN_CONCURRENCY must be defined"}
+    TEMPEST_IMAGE_NAME=${TEMPEST_IMAGE_NAME:?"TEMPEST_IMAGE_NAME must be defined"}
+}
+
+# Setup the environment. tempestrunrc file must exist, if not we fail
+source /etc/tempestrunrc
+check_environment
 
 cd /opt/stack/tempest
 

elements/tempest/os-apply-config/etc/tempestrunrc

@@ -0,0 +1,16 @@
+{{#tempestrun.concurrency}}
+# Number of test processes spawned by testr
+TEMPEST_RUN_CONCURRENCY={{tempestrun.concurrency}}
+{{/tempestrun.concurrency}}
+{{^tempestrun.concurrency}}
+# Number of test processes spawned by testr
+TEMPEST_RUN_CONCURRENCY=0
+{{/tempestrun.concurrency}}
+{{#tempestrun.image}}
+# Name of the test image to be used
+TEMPEST_IMAGE_NAME={{tempestrun.image}}
+{{/tempestrun.image}}
+{{^tempestrun.image}}
+# Name of the test image to be used
+TEMPEST_IMAGE_NAME=user
+{{/tempestrun.image}}