Contrail charms

Change-Id: I2d259d03f63fce38348b8384e26ac23e3fce44a8
Signed-off-by: Stuart Mackie <wsmackie@juniper.net>

1 files changed, 55 insertions, 0 deletions

diff --git a/contrail-analytics/hooks/charmhelpers/core/decorators.py b/contrail-analytics/hooks/charmhelpers/core/decorators.py
new file mode 100644
index 0000000..6ad41ee
--- /dev/null
+++ b/contrail-analytics/hooks/charmhelpers/core/decorators.py
@@ -0,0 +1,55 @@
+# Copyright 2014-2015 Canonical Limited.
+#
+# 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.
+
+#
+# Copyright 2014 Canonical Ltd.
+#
+# Authors:
+#  Edward Hope-Morley <opentastic@gmail.com>
+#
+
+import time
+
+from charmhelpers.core.hookenv import (
+    log,
+    INFO,
+)
+
+
+def retry_on_exception(num_retries, base_delay=0, exc_type=Exception):
+    """If the decorated function raises exception exc_type, allow num_retries
+    retry attempts before raise the exception.
+    """
+    def _retry_on_exception_inner_1(f):
+        def _retry_on_exception_inner_2(*args, **kwargs):
+            retries = num_retries
+            multiplier = 1
+            while True:
+                try:
+                    return f(*args, **kwargs)
+                except exc_type:
+                    if not retries:
+                        raise
+
+                delay = base_delay * multiplier
+                multiplier += 1
+                log("Retrying '%s' %d more times (delay=%s)" %
+                    (f.__name__, retries, delay), level=INFO)
+                retries -= 1
+                if delay:
+                    time.sleep(delay)
+
+        return _retry_on_exception_inner_2
+
+    return _retry_on_exception_inner_1