tox: generate config file on test run

We already do that for Aodh and Gnocchi, and that makes sure we don't
break the config generator when committing new things.

Change-Id: I049f86dc85d7d4c365cdd622cefd4025ae0cebc3

generate-config-file.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+oslo-config-generator --output-file etc/ceilometer/ceilometer.conf \
+    --namespace ceilometer \
+    --namespace oslo.concurrency \
+    --namespace oslo.db \
+    --namespace oslo.log \
+    --namespace oslo.messaging \
+    --namespace oslo.policy \
+    --namespace oslo.service.service \
+    --namespace keystonemiddleware.auth_token

tox.ini

@@ -13,6 +13,7 @@ setenv = VIRTUAL_ENV={envdir}
          OS_TEST_PATH=ceilometer/tests/unit
 commands =
    python setup.py testr --slowest --testr-args="{posargs}"
+   {toxinidir}/generate-config-file.sh
 whitelist_externals = bash
 
 # TODO(ityaptin): With separation tests to unit and functional folders we need
@@ -93,16 +94,7 @@ commands =
     bash -c "find ceilometer -type f -regex '.*\.pot?' -print0|xargs -0 -n 1 msgfmt --check-format -o /dev/null"
 
 [testenv:genconfig]
-commands =
+commands = {toxinidir}/generate-config-file.sh
-    oslo-config-generator --output-file etc/ceilometer/ceilometer.conf \
-    --namespace ceilometer \
-    --namespace oslo.concurrency \
-    --namespace oslo.db \
-    --namespace oslo.log \
-    --namespace oslo.messaging \
-    --namespace oslo.policy \
-    --namespace oslo.service.service \
-    --namespace keystonemiddleware.auth_token
 
 [testenv:docs]
 commands = python setup.py build_sphinx