Data in transit over networks should be protected wherever possible. Although some data may not appear to have strong confidentiality or integrity requirements it is best practice to secure it.
When building any application that communicates over a network we have to assume that we do not control the network that the data travels over. We should consider that the network may have hostile actors who will attempt to view or change the data that we are transmitting.
OpenStack API calls often contain credentials or tokens that are very sensitive. If they are sent in plaintext they may be modified or stolen.
It is very important that API calls are protected from malicious third parties viewing them or tampering with their content - even for communications between services on an internal network.
Consider a server process that reports the current number of stars in the sky and sends the data over the network to clients using a simple webpage. There is no strong confidentiality requirement for this; the data is not secret. However integrity is important. An attacker on the network could alter the communications going from the server to clients and inject malicious traffic such as browser exploits into the HTTP stream, thus compromising vulnerable clients.
cfg.StrOpt('protocol', default='http', help='Default protocol to use when connecting to glance.'),
cfg.StrOpt('protocol', default='https', help='Default protocol to use when connecting to glance.'),