Support to create public trove instance

- The users need to specify the network to create Trove instance, but
  trove-taskmanager will create port in that network for Nova instance
  creation. Using port gives Trove more capabilities to define how the
  database service is exposed.
- Deprecate ICMP protocol for the instance.
- Restrict 'nics' parameter for creating instance.
- Add 'access' parameter for creating instance.
- Add 'public_network_id' option in order to create floating IP for the
  instance.
- Do not create records for security groups, but Trove can still delete
  existing instances for backward compatibility.
- Delete unreasonable Host, Account, Storage API.

Story: 2006500
Task: 36468
Task: 36466
Change-Id: I80827e1ad5e6b130cbf94c2bb7a909c44d5cf1e5

1 files changed, 7 insertions, 4 deletions

diff --git a/trove/common/utils.py b/trove/common/utils.py
index 91ed1698..c6a730ac 100644
--- a/trove/common/utils.py
+++ b/trove/common/utils.py
@@ -185,16 +185,19 @@ class MethodInspector(object):
 
 def build_polling_task(retriever, condition=lambda value: value,
                        sleep_time=1, time_out=0):
+    """Run a function in a loop with backoff on error.
+
+    The condition function runs based on the retriever function result.
+    """
 
     def poll_and_check():
         obj = retriever()
         if condition(obj):
             raise loopingcall.LoopingCallDone(retvalue=obj)
 
-    return loopingcall.BackOffLoopingCall(
-        f=poll_and_check).start(initial_delay=False,
-                                starting_interval=sleep_time,
-                                max_interval=30, timeout=time_out)
+    call = loopingcall.BackOffLoopingCall(f=poll_and_check)
+    return call.start(initial_delay=False, starting_interval=sleep_time,
+                      max_interval=30, timeout=time_out)
 
 
 def wait_for_task(polling_task):