Add option for retry number of connection attempts

This patch adds a new option (-r | --retries) to specify how many times the
client should attempt to connect to the Neutron server when using idempotent
methods (GET, PUT and DELETE). The patch also provides more user-friendly
message when it's impossible to connect to Neutron server from CLI and
ensures that connection-related exceptions are raised to the caller by
default when neutronclient is used as a library.

DocImpact
Closes-Bug: #1312225

Change-Id: Id74d7cf9a0e8c5d2cd3ee4851c883d5286bea19d

1 files changed, 17 insertions, 2 deletions

diff --git a/neutronclient/v2_0/client.py b/neutronclient/v2_0/client.py
index a102781..630d413 100644
--- a/neutronclient/v2_0/client.py
+++ b/neutronclient/v2_0/client.py
@@ -129,6 +129,12 @@ class Client(object):
                             http requests. (optional)
     :param bool insecure: SSL certificate validation. (optional)
     :param string ca_cert: SSL CA bundle file to use. (optional)
+    :param integer retries: How many times idempotent (GET, PUT, DELETE)
+                            requests to Neutron server should be retried if
+                            they fail (default: 0).
+    :param bool raise_errors: If True then exceptions caused by connection
+                              failure are propagated to the caller.
+                              (default: True)
 
     Example::
 
@@ -1194,7 +1200,8 @@ class Client(object):
         self.version = '2.0'
         self.format = 'json'
         self.action_prefix = "/v%s" % (self.version)
-        self.retries = 0
+        self.retries = kwargs.get('retries', 0)
+        self.raise_errors = kwargs.get('raise_errors', True)
         self.retry_interval = 1
 
     def _handle_fault_response(self, status_code, response_body):
@@ -1303,8 +1310,16 @@ class Client(object):
                 if i < self.retries:
                     _logger.debug('Retrying connection to Neutron service')
                     time.sleep(self.retry_interval)
+                elif self.raise_errors:
+                    raise
 
-        raise exceptions.ConnectionFailed(reason=_("Maximum attempts reached"))
+        if self.retries:
+            msg = (_("Failed to connect to Neutron server after %d attempts")
+                   % max_attempts)
+        else:
+            msg = _("Failed to connect Neutron server")
+
+        raise exceptions.ConnectionFailed(reason=msg)
 
     def delete(self, action, body=None, headers=None, params=None):
         return self.retry_request("DELETE", action, body=body,