Implement kubernetes & kubernetes-ro services

pkg/master/publish.go

@@ -0,0 +1,113 @@
+/*
+Copyright 2014 Google Inc. 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 master
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+
+	"github.com/golang/glog"
+)
+
+func (m *Master) serviceWriterLoop(stop chan struct{}) {
+	for {
+		// Update service & endpoint records.
+		// TODO: when it becomes possible to change this stuff,
+		// stop polling and start watching.
+		// TODO: add endpoints of all replicas, not just the elected master.
+		if m.readWriteServer != "" {
+			if err := m.createMasterServiceIfNeeded("kubernetes", 443); err != nil {
+				glog.Errorf("Can't create rw service: %v", err)
+			}
+			if err := m.setEndpoints("kubernetes", []string{m.readWriteServer}); err != nil {
+				glog.Errorf("Can't create rw endpoints: %v", err)
+			}
+		} else {
+			m.deleteMasterService("kubernetes")
+		}
+		if m.readOnlyServer != "" {
+			if err := m.createMasterServiceIfNeeded("kubernetes-ro", 80); err != nil {
+				glog.Errorf("Can't create ro service: %v", err)
+			}
+			if err := m.setEndpoints("kubernetes-ro", []string{m.readOnlyServer}); err != nil {
+				glog.Errorf("Can't create rw endpoints: %v", err)
+			}
+		} else {
+			m.deleteMasterService("kubernetes-ro")
+		}
+
+		select {
+		case <-stop:
+			return
+		case <-time.After(10 * time.Second):
+		}
+	}
+}
+
+// createMasterServiceIfNeeded will create the specified service if it
+// doesn't already exist.
+func (m *Master) createMasterServiceIfNeeded(serviceName string, port int) error {
+	ctx := api.NewDefaultContext()
+	if _, err := m.serviceRegistry.GetService(ctx, serviceName); err == nil {
+		// The service already exists.
+		return nil
+	}
+	svc := &api.Service{
+		ObjectMeta: api.ObjectMeta{
+			Name:      serviceName,
+			Namespace: "default",
+		},
+		Port: port,
+		// We're going to add the endpoints by hand, so this selector is mainly to
+		// prevent identification of other pods. This selector will be useful when
+		// we start hosting apiserver in a pod.
+		Selector: map[string]string{"provider": "kubernetes", "component": "apiserver"},
+	}
+	// Kids, don't do this at home: this is a hack. There's no good way to call the business
+	// logic which lives in the REST object from here.
+	c, err := m.storage["services"].Create(ctx, svc)
+	if err != nil {
+		return err
+	}
+	resp := <-c
+	if _, ok := resp.(*api.Service); ok {
+		// If all worked, we get back an *api.Service object.
+		return nil
+	}
+	return fmt.Errorf("Unexpected response: %#v", resp)
+}
+
+func (m *Master) deleteMasterService(serviceName string) {
+	ctx := api.NewDefaultContext()
+	m.serviceRegistry.DeleteService(ctx, serviceName)
+}
+
+// setEndpoints sets the endpoints for the given service.
+func (m *Master) setEndpoints(serviceName string, endpoints []string) error {
+	ctx := api.NewDefaultContext()
+	e, err := m.endpointRegistry.GetEndpoints(ctx, serviceName)
+	if err != nil {
+		e = &api.Endpoints{}
+		// Fill in ID if it didn't exist already
+		e.ObjectMeta.Name = serviceName
+		e.ObjectMeta.Namespace = "default"
+	}
+	e.Endpoints = endpoints
+	return m.endpointRegistry.UpdateEndpoints(ctx, e)
+}