Refactor process_router method in L3 agent

Refactors the process_router method of the L3NATAgent class to several methods
that coherently group functionallity. The aim is to make the code more readable
and maintainable. There is no functional change in this patch.

Partially-Implements: bp restructure-l3-agent

Change-Id: Id35a5f10cd7d2dda565bffb14fc6a2fbd7eef3ea

diff --git a/neutron/agent/l3/agent.py b/neutron/agent/l3/agent.py
index 9ddf430f92a7bcad4decc34179b2b7db405cd309..bdd23759d6044a050b37cf74d579e5f93101e411 100644 (file)
--- a/neutron/agent/l3/agent.py
+++ b/neutron/agent/l3/agent.py
@@ -568,15 +568,8 @@ class L3NATAgent(firewall_l3_agent.FWaaSL3AgentRpcCallback,
         ip_devs = ip_wrapper.get_devices(exclude_loopback=True)
         return [ip_dev.name for ip_dev in ip_devs]
 
-    @common_utils.exception_logger()
-    def process_router(self, ri):
-        # TODO(mrsmith) - we shouldn't need to check here
-        if 'distributed' not in ri.router:
-            ri.router['distributed'] = False
-        ri.iptables_manager.defer_apply_on()
-        ex_gw_port = self._get_ex_gw_port(ri)
+    def _process_internal_ports(self, ri):
         internal_ports = ri.router.get(l3_constants.INTERFACE_KEY, [])
-        snat_ports = ri.router.get(l3_constants.SNAT_ROUTER_INTF_KEY, [])
         existing_port_ids = set([p['id'] for p in ri.internal_ports])
         current_port_ids = set([p['id'] for p in internal_ports
                                 if p['admin_state_up']])
@@ -604,6 +597,7 @@ class L3NATAgent(firewall_l3_agent.FWaaSL3AgentRpcCallback,
                     netaddr.IPNetwork(p['subnet']['cidr']).version == 6):
                 old_ipv6_port = True
 
+        # Enable RA
         if new_ipv6_port or old_ipv6_port:
             ra.enable_ipv6_ra(ri.router_id,
                               ri.ns_name,
@@ -624,8 +618,8 @@ class L3NATAgent(firewall_l3_agent.FWaaSL3AgentRpcCallback,
                                namespace=ri.ns_name,
                                prefix=INTERNAL_DEV_PREFIX)
 
-        # TODO(salv-orlando): RouterInfo would be a better place for
-        # this logic too
+    def _process_external_gateway(self, ri):
+        ex_gw_port = self._get_ex_gw_port(ri)
         ex_gw_port_id = (ex_gw_port and ex_gw_port['id'] or
                          ri.ex_gw_port and ri.ex_gw_port['id'])
 
@@ -651,6 +645,7 @@ class L3NATAgent(firewall_l3_agent.FWaaSL3AgentRpcCallback,
         elif not ex_gw_port and ri.ex_gw_port:
             self.external_gateway_removed(ri, ri.ex_gw_port, interface_name)
 
+        existing_devices = self._get_existing_devices(ri)
         stale_devs = [dev for dev in existing_devices
                       if dev.startswith(EXTERNAL_DEV_PREFIX)
                       and dev != interface_name]
@@ -662,51 +657,70 @@ class L3NATAgent(firewall_l3_agent.FWaaSL3AgentRpcCallback,
                                namespace=ri.ns_name,
                                prefix=EXTERNAL_DEV_PREFIX)
 
-        # Process static routes for router
-        self.routes_updated(ri)
         # Process SNAT rules for external gateway
         if (not ri.router['distributed'] or
             ex_gw_port and ri.router['gw_port_host'] == self.host):
             ri.perform_snat_action(self._handle_router_snat_rules,
                                    interface_name)
 
-        # Process SNAT/DNAT rules for floating IPs
+    def _process_snat_dnat_for_fip(self, ri):
+        ex_gw_port = self._get_ex_gw_port(ri)
+        if not ex_gw_port:
+            return
         fip_statuses = {}
         try:
-            if ex_gw_port:
-                existing_floating_ips = ri.floating_ips
-                self.process_router_floating_ip_nat_rules(ri)
-                ri.iptables_manager.defer_apply_off()
-                # Once NAT rules for floating IPs are safely in place
-                # configure their addresses on the external gateway port
-                fip_statuses = self.process_router_floating_ip_addresses(
-                    ri, ex_gw_port)
+            existing_floating_ips = ri.floating_ips
+            self.process_router_floating_ip_nat_rules(ri)
+            ri.iptables_manager.defer_apply_off()
+            # Once NAT rules for floating IPs are safely in place
+            # configure their addresses on the external gateway port
+            fip_statuses = self.process_router_floating_ip_addresses(
+                ri, ex_gw_port)
         except Exception:
             # TODO(salv-orlando): Less broad catching
             # All floating IPs must be put in error state
             for fip in ri.router.get(l3_constants.FLOATINGIP_KEY, []):
                 fip_statuses[fip['id']] = l3_constants.FLOATINGIP_STATUS_ERROR
 
-        if ex_gw_port:
-            # Identify floating IPs which were disabled
-            ri.floating_ips = set(fip_statuses.keys())
-            for fip_id in existing_floating_ips - ri.floating_ips:
-                fip_statuses[fip_id] = l3_constants.FLOATINGIP_STATUS_DOWN
-            # Update floating IP status on the neutron server
-            self.plugin_rpc.update_floatingip_statuses(
-                self.context, ri.router_id, fip_statuses)
-
-        # Update ex_gw_port and enable_snat on the router info cache
-        ri.ex_gw_port = ex_gw_port
-        ri.snat_ports = snat_ports
-        ri.enable_snat = ri.router.get('enable_snat')
+        # Identify floating IPs which were disabled
+        ri.floating_ips = set(fip_statuses.keys())
+        for fip_id in existing_floating_ips - ri.floating_ips:
+            fip_statuses[fip_id] = l3_constants.FLOATINGIP_STATUS_DOWN
+        # Update floating IP status on the neutron server
+        self.plugin_rpc.update_floatingip_statuses(
+            self.context, ri.router_id, fip_statuses)
 
+    def _process_ha_router(self, ri):
         if ri.is_ha:
             if ri.ha_port:
                 ri.spawn_keepalived()
             else:
                 ri.disable_keepalived()
 
+    @common_utils.exception_logger()
+    def process_router(self, ri):
+        # TODO(mrsmith) - we shouldn't need to check here
+        if 'distributed' not in ri.router:
+            ri.router['distributed'] = False
+
+        ri.iptables_manager.defer_apply_on()
+        self._process_internal_ports(ri)
+        self._process_external_gateway(ri)
+
+        # Process static routes for router
+        self.routes_updated(ri)
+
+        # Process SNAT/DNAT rules for floating IPs
+        self._process_snat_dnat_for_fip(ri)
+
+        # Enable or disable keepalived for ha routers
+        self._process_ha_router(ri)
+
+        # Update ex_gw_port and enable_snat on the router info cache
+        ri.ex_gw_port = self._get_ex_gw_port(ri)
+        ri.snat_ports = ri.router.get(l3_constants.SNAT_ROUTER_INTF_KEY, [])
+        ri.enable_snat = ri.router.get('enable_snat')
+
     def _handle_router_snat_rules(self, ri, ex_gw_port,
                                   interface_name, action):
         # Remove all the rules