Add support for updating AWS routing table entries

src/bosh_aws_cpi/lib/cloud/aws/instance.rb

@@ -83,6 +83,30 @@ def exists?
       @aws_instance.exists? && @aws_instance.status != :terminated
     end
 
+    def update_routing_tables(route_definitions)
+      if route_definitions.length > 0
+        @logger.debug("Associating instance with destinations in the routing tables")
+        tables = @aws_instance.vpc.route_tables
+        route_definitions.each do |definition|
+          @logger.debug("Finding routing table '#{definition["table_id"]}'")
+          table = tables[definition["table_id"]]
+          @logger.debug("Sending traffic for '#{definition["destination"]}' to '#{@aws_instance.id}' in '#{definition["table_id"]}'")
+
+          existing = false
+          table.routes.each do |route|
+              if definition["destination"] == route.destination_cidr_block
+                  existing = true
+              end
+          end
+          if existing
+            table.replace_route(definition["destination"], { :instance => @aws_instance })
+          else
+            table.create_route(definition["destination"], { :instance => @aws_instance })
+          end
+        end
+      end
+    end
+
     def attach_to_load_balancers(load_balancer_ids)
       load_balancer_ids.each do |load_balancer_id|
         lb = @elb.load_balancers[load_balancer_id]

src/bosh_aws_cpi/lib/cloud/aws/instance_manager.rb

@@ -33,6 +33,7 @@ def create(agent_id, stemcell_id, resource_pool, networks_spec, disk_locality, e
         # attach to a load balancer, the instance must be running.
         instance.wait_for_running
         instance.attach_to_load_balancers(resource_pool['elbs'] || [])
+        instance.update_routing_tables(resource_pool['advertised_instance_routes'] || [])
       rescue => e
         @logger.warn("Failed to configure instance '#{instance.id}': #{e.inspect}")
         begin

src/bosh_aws_cpi/spec/unit/instance_spec.rb

@@ -142,6 +142,32 @@ module Bosh::AwsCloud
       end
     end
 
+    describe '#update_routing_tables' do
+      let(:fake_vpc) { instance_double('AWS::EC2::VPC') }
+      let(:fake_tables) { instance_double('AWS::EC2::RouteTableCollection') }
+      let(:fake_table) { instance_double('AWS::EC2::RouteTable') }
+      let(:fake_route) { instance_double('AWS::EC2::Route') }
+      let(:fake_routes) {[ fake_route ]}
+
+      before do
+        allow(aws_instance).to receive(:vpc).and_return(fake_vpc)
+        allow(fake_vpc).to receive(:route_tables).and_return(fake_tables)
+        allow(fake_tables).to receive(:[]).with('r-12345').and_return(fake_table)
+        allow(fake_table).to receive(:routes).and_return(fake_routes)
+        allow(fake_route).to receive(:destination_cidr_block).and_return("10.0.0.0/16")
+      end
+      it 'updates the routing table entry with the instance ID when finding an existing route' do
+          destination = "10.0.0.0/16"
+          expect(fake_table).to receive(:replace_route).with(destination, { :instance => aws_instance })
+          instance.update_routing_tables [{ "table_id" => "r-12345", "destination" => destination }]
+      end
+      it 'creates a routing table entry with the instance ID when the route does not exist' do
+          destination = "10.5.0.0/16"
+          expect(fake_table).to receive(:create_route).with(destination, { :instance => aws_instance })
+          instance.update_routing_tables [{ "table_id" => "r-12345", "destination" => destination }]
+      end
+    end
+
     describe '#attach_to_load_balancers' do
       before { allow(elb).to receive(:load_balancers).and_return(load_balancers) }
       let(:load_balancers) { { 'fake-lb1-id' => load_balancer1, 'fake-lb2-id' => load_balancer2 } }