Adds output_policy_command.py in scripts directory

The script outputs openstack commands that create policy and policy
rules defined in a config file. The config file is formatted in json
style. Sample config file is located at
congress/scripts/preload-policies/policy-rules.json.sample

Change-Id: Ica6bb1bfdc3092a306a890e38ee156ffc71821c0
Partial-Bug: #1638742

scripts/preload-policies/output_policy_command.py

@@ -0,0 +1,90 @@
+#!/usr/bin/python
+# Copyright (c) 2017 NTT All rights reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+# This script outputs pre definded policies and rules in a config file.
+# The config file content should look like following:
+# {
+#   "policies":
+#     [
+#       {
+#         "name": "sample_policy",
+#         "rules": [
+#                    {
+#                      "rule": "p(x):- q(x)",
+#                      "name": "rule1"
+#                    },
+#                    {
+#                      "rule": "q(1)"
+#                    },
+#                    {
+#                      "rule": "q('sample-row')"
+#                    },
+#                    {
+#                      "rule": "server_ids(x):- nova:servers(id=x)"
+#                    }
+#         ]
+#       }
+#    ]
+# }
+#
+# Config file option:
+#    - "name" key in rule object is option
+#
+# sample config file is located at
+# /path/to/congress/scripts/preload-polices/policy-rules.json.sample
+
+
+import argparse
+import json
+import sys
+
+OPENSTACK_COMMAND = 'openstack congress'
+POLICY_CREATE = 'policy create'
+RULE_CREATE = 'policy rule create'
+NAME_OPTION = '--name %s'
+
+
+def load_policies(policy_file):
+    with open(args.policy_file, 'r') as f:
+        data = f.read()
+        policies = json.loads(data)
+    return policies
+
+
+def main(args):
+    defined_policies = load_policies(args.policy_file)
+
+    for p in defined_policies['policies']:
+        # create defined policy
+        sys.stdout.write(' '.join([OPENSTACK_COMMAND, POLICY_CREATE,
+                                   p['name'], '\n']))
+        # create defined rules
+        for r in p['rules']:
+            cmd_string = [OPENSTACK_COMMAND, RULE_CREATE]
+            if r.get('name'):
+                cmd_string.append(NAME_OPTION % r['name'])
+            cmd_string.extend([p['name'], '"%s"' % r['rule'], '\n'])
+            sys.stdout.write(' '.join(cmd_string))
+
+
+parser = argparse.ArgumentParser(description='Output pre-defined policy in '
+                                             'openstack command style.')
+parser.add_argument('policy_file', type=str,
+                    help='Path to pre defined policies and rules.')
+
+
+if __name__ == '__main__':
+    args = parser.parse_args()
+    main(args)

scripts/preload-policies/policy-rules.json.sample

@@ -0,0 +1,23 @@
+{
+  "policies":
+    [
+      {
+        "name": "sample_policy",
+        "rules": [
+                   {
+                     "rule": "p(x):- q(x)",
+                     "name": "rule1"
+                   },
+                   {
+                     "rule": "q(1)"
+                   },
+                   {
+                     "rule": "q('sample-row')"
+                   },
+                   {
+                     "rule": "server_ids(x):- nova:servers(id=x)"
+                   }
+        ]
+      }
+   ]
+}