Currently, we create a compute.rpcapi.ComputeAPI object during
NovaProxyRequestHandler.__init__ in order to make calls to nova-compute
for console token authorizations (port validation). This is problematic
in the event that we receive a TCP RST as it results in constructing a
ComputeAPI object only to throw it away and a large number of TCP RST
sent can cause excessive resource consumption.
This moves the creation of the ComputeAPI object from __init__ to being
lazily instantiated upon first use by access of a property, thus
avoiding creation of ComputeAPI objects when we receive TCP RST
messages.
Closes-Bug: #1816727
Change-Id: I3fe5540ea460fb32767b5e681295fdaf89ce17c5
(cherry picked from commit e4fa061f17)
b1b28169af