Add app_cred_interface_type config file option

Currently the interface field in generated app creds is parsed from nova_client.endpoint_type in magnum.conf which is undesirable. We fix the issue here by adding an extra config option to the capi_helm group with a default value of 'public'.

Change-Id: I2b714a1a7429f28bfbc82177f75706e11de657d4

magnum_capi_helm/common/app_creds.py

@@ -62,7 +62,7 @@ def _create_app_cred(context, cluster):
             "openstack": {
                 "identity_api_version": 3,
                 "region_name": osc.cinder_region_name(),
-                "interface": CONF.nova_client.endpoint_type.replace("URL", ""),
+                "interface": CONF.capi_helm.app_cred_interface_type,
                 # This config item indicates whether TLS should be
                 # verified when connecting to the OpenStack API
                 "verify": CONF.drivers.verify_ca,

magnum_capi_helm/conf.py

@@ -117,6 +117,14 @@ capi_helm_opts = [
             "volume binding and dynamic provisioning should occur."
         ),
     ),
+    cfg.StrOpt(
+        "app_cred_interface_type",
+        default="public",
+        help=(
+            "The value to use in the interface field of "
+            "generated application credentials."
+        ),
+    ),
 ]
 
 CONF = cfg.CONF