Automatic merge from submit-queue (batch tested with PRs 40932, 41896, 41815, 41309, 41628)
Add custom CA file to openstack cloud provider config
**What this PR does / why we need it**: Adds ability to specify custom CA bundle file to verify OpenStack endpoint against. Useful in tests and PoC deployments. Similar to what https://github.com/kubernetes/kubernetes/pull/35488 did for authentication.
**Which issue this PR fixes**: None
**Special notes for your reviewer**: Based on https://github.com/kubernetes/kubernetes/pull/35488 which added support for custom CA file for authentication.
**Release note**:
This change migrates the 'openstack' provider and 'keystone'
authenticator plugin to the newer gophercloud/gophercloud library.
Note the 'rackspace' provider still uses rackspace/gophercloud.
Fixes#30404
In cases where insecure OpenStack endpoint is to be used
(e.g., when testing), gophercloud will fail to connect
to such endpoints. This patch adds support for custom CA
file configuration option, which, when provided, will
make gophercloud validate OpenStack endpoint against
certificate(s) read from file specified in that option.
This change implements the Routes API using Neutron's "extraroute"
extension.
To use, this requires all the nodes to be on the same Neutron network
and the UUID of the Neutron router on that network.
Required cloud provider config section:
[Route]
router-id = <UUID of Neutron router>
Ensure kube-controllermanager is started with (non-default)
`--allocate-node-cidrs=true` and set `--cluster-cidr` to the POD
super-subnet (a private /16 would be reasonable).
Based on an earlier version by @timbyr (#19473)
