Implements provider subnets

JIRA:NCP-1580

Implements hooks for showing provider subnets, which are merely aliases
for subnets owned by provider networks. Unlike provider networks, they
are merely placeholders and will never be related in the schema to any
other object.

quark/plugin_views.py

@@ -71,16 +71,20 @@ def _make_network_dict(network, fields=None):
         else:
             res["subnets"] = [s["id"] for s in network.get("subnets", [])]
     else:
-        res["subnets"] = []
+        res["subnets"] = STRATEGY.subnet_ids_for_network(network["id"])
     return res
 
 
 def _make_subnet_dict(subnet, fields=None):
     dns_nameservers = [str(netaddr.IPAddress(dns["ip"]))
-                       for dns in subnet.get("dns_nameservers")]
-    net_id = subnet["network_id"]
+                       for dns in subnet.get("dns_nameservers", [])]
+    subnet_id = subnet.get("id")
+    if STRATEGY.is_provider_subnet(subnet_id):
+        net_id = STRATEGY.get_network_for_subnet(subnet_id)
+    else:
+        net_id = subnet["network_id"]
 
-    res = {"id": subnet.get("id"),
+    res = {"id": subnet_id,
            "name": subnet.get("name"),
            "tenant_id": subnet.get("tenant_id"),
            "network_id": net_id,
@@ -93,7 +97,8 @@ def _make_subnet_dict(subnet, fields=None):
     if CONF.QUARK.show_subnet_ip_policy_id:
         res['ip_policy_id'] = subnet.get("ip_policy_id")
 
-    if CONF.QUARK.show_allocation_pools:
+    if (CONF.QUARK.show_allocation_pools and not
+            STRATEGY.is_provider_subnet(subnet_id)):
         res["allocation_pools"] = subnet.allocation_pools
     else:
         res["allocation_pools"] = []
@@ -102,11 +107,10 @@ def _make_subnet_dict(subnet, fields=None):
         return {"destination": route["cidr"],
                 "nexthop": route["gateway"]}
 
-    # TODO(mdietz): really inefficient, should go away
     res["gateway_ip"] = None
     res["host_routes"] = []
     default_found = False
-    for route in subnet["routes"]:
+    for route in subnet.get("routes", []):
         netroute = netaddr.IPNetwork(route["cidr"])
         if _is_default_route(netroute):
             # NOTE(mdietz): This has the potential to find more than one
@@ -252,8 +256,7 @@ def _make_ports_list(query, fields=None):
 def _make_subnets_list(query, fields=None):
     subnets = []
     for subnet in query:
-        subnet_dict = _make_subnet_dict(subnet, fields=fields)
-        subnets.append(subnet_dict)
+        subnets.append(_make_subnet_dict(subnet, fields=fields))
     return subnets