Add policy sample generation

This adds the entry point and config file necessary for using the
oslo.policy sample generation script. It also adds a tox target to
simplify the usage of it.

The command is also run in the docs tox target since the sample file
can be considered documentation.

Change-Id: I18a1fa567fc04b0e0a37c02f20024b2ce483f060
Partially-Implements: bp policy-in-code

.gitignore

@@ -33,6 +33,7 @@ doc/build/*
 api-guide/build/*
 api-ref/build/*
 etc/nova/nova.conf.sample
+etc/nova/policy.yaml.sample
 instances
 keeper
 keys

etc/nova/nova-policy-generator.conf

@@ -0,0 +1,3 @@
+[DEFAULT]
+output_file = etc/nova/policy.yaml.sample
+namespace = nova

setup.cfg

@@ -36,6 +36,13 @@ oslo.config.opts =
 oslo.config.opts.defaults =
     nova.api = nova.common.config:set_middleware_defaults
 
+oslo.policy.policies =
+    # The sample policies will be ordered by entry point and then by list
+    # returned from that entry point. If more control is desired split out each
+    # list_rules method into a separate entry point rather than using the
+    # aggregate method.
+    nova = nova.policies:list_rules
+
 nova.compute.monitors.cpu =
     virt_driver = nova.compute.monitors.cpu.virt_driver:Monitor
 nova.compute.resources =

tox.ini

@@ -60,6 +60,9 @@ commands =
 [testenv:genconfig]
 commands = oslo-config-generator --config-file=etc/nova/nova-config-generator.conf
 
+[testenv:genpolicy]
+commands = oslopolicy-sample-generator --config-file=etc/nova/nova-policy-generator.conf
+
 [testenv:cover]
 # Also do not run test_coverage_ext tests while gathering coverage as those
 # tests conflict with coverage.
@@ -87,6 +90,7 @@ commands =
   python setup.py build_sphinx
   bash -c '! find doc/ -type f -name *.json | xargs -t -n1 python -m json.tool 2>&1 > /dev/null | grep -B1 -v ^python'
   oslo-config-generator --config-file=etc/nova/nova-config-generator.conf
+  oslopolicy-sample-generator --config-file=etc/nova/nova-policy-generator.conf
   sphinx-build -W -b html api-guide/source api-guide/build/html
   sphinx-build -W -b html api-ref/source api-ref/build/html