Route creation reconciler loop.

pkg/cloudprovider/routecontroller/routecontroller.go

@@ -0,0 +1,145 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package routecontroller
+
+import (
+	"fmt"
+	"net"
+	"strings"
+	"time"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/fields"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/golang/glog"
+)
+
+type RouteController struct {
+	routes      cloudprovider.Routes
+	kubeClient  client.Interface
+	clusterName string
+	clusterCIDR *net.IPNet
+}
+
+const k8sNodeRouteTag = "k8s-node-route"
+
+func New(routes cloudprovider.Routes, kubeClient client.Interface, clusterName string, clusterCIDR *net.IPNet) *RouteController {
+	return &RouteController{
+		routes:      routes,
+		kubeClient:  kubeClient,
+		clusterName: clusterName,
+		clusterCIDR: clusterCIDR,
+	}
+}
+
+func (rc *RouteController) Run(syncPeriod time.Duration) {
+	go util.Forever(func() {
+		if err := rc.reconcileNodeRoutes(); err != nil {
+			glog.Errorf("Couldn't reconcile node routes: %v", err)
+		}
+	}, syncPeriod)
+}
+
+func (rc *RouteController) reconcileNodeRoutes() error {
+	routeList, err := rc.routes.ListRoutes(rc.truncatedClusterName() + "-.*")
+	if err != nil {
+		return fmt.Errorf("error listing routes: %v", err)
+	}
+	nodeList, err := rc.kubeClient.Nodes().List(labels.Everything(), fields.Everything())
+	if err != nil {
+		return fmt.Errorf("error listing nodes: %v", err)
+	}
+	return rc.reconcile(nodeList.Items, routeList)
+}
+
+func (rc *RouteController) reconcile(nodes []api.Node, routes []*cloudprovider.Route) error {
+	// nodeCIDRs maps nodeName->nodeCIDR
+	nodeCIDRs := make(map[string]string)
+	// routeMap maps routeTargetInstance->route
+	routeMap := make(map[string]*cloudprovider.Route)
+	for _, route := range routes {
+		routeMap[route.TargetInstance] = route
+	}
+	for _, node := range nodes {
+		// Check if we have a route for this node w/ the correct CIDR.
+		r := routeMap[node.Name]
+		if r == nil || r.DestinationCIDR != node.Spec.PodCIDR {
+			// If not, create the route.
+			route := &cloudprovider.Route{
+				Name:            rc.truncatedClusterName() + "-" + string(node.UID),
+				TargetInstance:  node.Name,
+				DestinationCIDR: node.Spec.PodCIDR,
+				Description:     k8sNodeRouteTag,
+			}
+			go func(route *cloudprovider.Route) {
+				if err := rc.routes.CreateRoute(route); err != nil {
+					glog.Errorf("Could not create route %s: %v", route.Name, err)
+				}
+			}(route)
+		}
+		nodeCIDRs[node.Name] = node.Spec.PodCIDR
+	}
+	for _, route := range routes {
+		if rc.isResponsibleForRoute(route) {
+			// Check if this route applies to a node we know about & has correct CIDR.
+			if nodeCIDRs[route.TargetInstance] != route.DestinationCIDR {
+				// Delete the route.
+				go func(routeName string) {
+					if err := rc.routes.DeleteRoute(routeName); err != nil {
+						glog.Errorf("Could not delete route %s: %v", routeName, err)
+					}
+				}(route.Name)
+			}
+		}
+	}
+	return nil
+}
+
+func (rc *RouteController) truncatedClusterName() string {
+	if len(rc.clusterName) > 26 {
+		return rc.clusterName[:26]
+	}
+	return rc.clusterName
+}
+
+func (rc *RouteController) isResponsibleForRoute(route *cloudprovider.Route) bool {
+	_, cidr, err := net.ParseCIDR(route.DestinationCIDR)
+	if err != nil {
+		glog.Errorf("Ignoring route %s, unparsable CIDR: %v", route.Name, err)
+		return false
+	}
+	// Not responsible if this route's CIDR is not within our clusterCIDR
+	lastIP := make([]byte, len(cidr.IP))
+	for i := range lastIP {
+		lastIP[i] = cidr.IP[i] | ^cidr.Mask[i]
+	}
+	if !rc.clusterCIDR.Contains(cidr.IP) || !rc.clusterCIDR.Contains(lastIP) {
+		return false
+	}
+	// Not responsible if route name doesn't start with <clusterName>
+	if !strings.HasPrefix(route.Name, rc.clusterName) {
+		return false
+	}
+	// Not responsible if route description != "k8s-node-route"
+	if route.Description != k8sNodeRouteTag {
+		return false
+	}
+	return true
+}