1 files changed, 49 insertions, 0 deletions
diff --git a/ceilometer/compute/util.py b/ceilometer/compute/util.py
new file mode 100644
index 00000000..ba142b45
--- /dev/null
+++ b/ceilometer/compute/util.py
@@ -0,0 +1,49 @@
+# -*- encoding: utf-8 -*-
+#
+# Copyright © 2014 Red Hat, Inc
+#
+# Author: Eoghan Glynn <eglynn@redhat.com>
+#
+# 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.
+
+from oslo.config import cfg
+
+
+OPTS = [
+    cfg.ListOpt('reserved_metadata_namespace',
+                default=['metering.'],
+                help='List of metadata prefixes reserved for metering use.'),
+    cfg.IntOpt('reserved_metadata_length',
+               default=256,
+               help='Limit on length of reserved metadata values.'),
+]
+
+cfg.CONF.register_opts(OPTS)
+
+
+def add_reserved_user_metadata(src_metadata, dest_metadata):
+    limit = cfg.CONF.reserved_metadata_length
+    user_metadata = {}
+    for prefix in cfg.CONF.reserved_metadata_namespace:
+        md = dict(
+            (k[len(prefix):].replace('.', '_'),
+             v[:limit] if isinstance(v, basestring) else v)
+            for k, v in src_metadata.items()
+            if (k.startswith(prefix) and
+                k[len(prefix):].replace('.', '_') not in dest_metadata)
+        )
+        user_metadata.update(md)
+    if user_metadata:
+        dest_metadata['user_metadata'] = user_metadata
+
+    return dest_metadata