add controller to autoregister APIServices

staging/src/k8s.io/kube-aggregator/pkg/controllers/autoregister/autoregister_controller.go

+/*
+Copyright 2017 The Kubernetes Authors.
+
+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 autoregister
+
+import (
+	"fmt"
+	"reflect"
+	"sync"
+	"time"
+
+	"github.com/golang/glog"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/conversion"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/client-go/tools/cache"
+	"k8s.io/client-go/util/workqueue"
+
+	"k8s.io/kube-aggregator/pkg/apis/apiregistration"
+	apiregistrationclient "k8s.io/kube-aggregator/pkg/client/clientset_generated/internalclientset/typed/apiregistration/internalversion"
+	informers "k8s.io/kube-aggregator/pkg/client/informers/internalversion/apiregistration/internalversion"
+	listers "k8s.io/kube-aggregator/pkg/client/listers/apiregistration/internalversion"
+)
+
+const (
+	AutoRegisterManagedLabel = "kube-aggregator.kubernetes.io/automanaged"
+)
+
+var (
+	cloner = conversion.NewCloner()
+)
+
+// AutoAPIServiceRegistration is an interface which callers can re-declare locally and properly cast to for
+// adding and removing APIServices
+type AutoAPIServiceRegistration interface {
+	// AddAPIServiceToSync adds an API service to auto-register.
+	AddAPIServiceToSync(in *apiregistration.APIService)
+	// RemoveAPIServiceToSync removes an API service to auto-register.
+	RemoveAPIServiceToSync(name string)
+}
+
+// autoRegisterController is used to keep a particular set of APIServices present in the API.  It is useful
+// for cases where you want to auto-register APIs like TPRs or groups from the core kube-apiserver
+type autoRegisterController struct {
+	apiServiceLister listers.APIServiceLister
+	apiServiceSynced cache.InformerSynced
+	apiServiceClient apiregistrationclient.APIServicesGetter
+
+	apiServicesToSyncLock sync.RWMutex
+	apiServicesToSync     map[string]*apiregistration.APIService
+
+	syncHandler func(apiServiceName string) error
+
+	// queue is where incoming work is placed to de-dup and to allow "easy" rate limited requeues on errors
+	queue workqueue.RateLimitingInterface
+}
+
+func NewAutoRegisterController(apiServiceInformer informers.APIServiceInformer, apiServiceClient apiregistrationclient.APIServicesGetter) *autoRegisterController {
+	c := &autoRegisterController{
+		apiServiceLister:  apiServiceInformer.Lister(),
+		apiServiceSynced:  apiServiceInformer.Informer().HasSynced,
+		apiServiceClient:  apiServiceClient,
+		apiServicesToSync: map[string]*apiregistration.APIService{},
+		queue:             workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), "autoregister"),
+	}
+	c.syncHandler = c.checkAPIService
+
+	apiServiceInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{
+		AddFunc: func(obj interface{}) {
+			cast := obj.(*apiregistration.APIService)
+			c.queue.Add(cast.Name)
+		},
+		UpdateFunc: func(_, obj interface{}) {
+			cast := obj.(*apiregistration.APIService)
+			c.queue.Add(cast.Name)
+		},
+		DeleteFunc: func(obj interface{}) {
+			cast, ok := obj.(*apiregistration.APIService)
+			if !ok {
+				tombstone, ok := obj.(cache.DeletedFinalStateUnknown)
+				if !ok {
+					glog.V(2).Infof("Couldn't get object from tombstone %#v", obj)
+					return
+				}
+				cast, ok = tombstone.Obj.(*apiregistration.APIService)
+				if !ok {
+					glog.V(2).Infof("Tombstone contained unexpected object: %#v", obj)
+					return
+				}
+			}
+			c.queue.Add(cast.Name)
+		},
+	})
+
+	return c
+}
+
+func (c *autoRegisterController) Run(threadiness int, stopCh chan struct{}) {
+	// don't let panics crash the process
+	defer utilruntime.HandleCrash()
+	// make sure the work queue is shutdown which will trigger workers to end
+	defer c.queue.ShutDown()
+
+	glog.Infof("Starting autoregister controller")
+	defer glog.Infof("Shutting down autoregister controller")
+
+	// wait for your secondary caches to fill before starting your work
+	if !cache.WaitForCacheSync(stopCh, c.apiServiceSynced) {
+		return
+	}
+
+	// start up your worker threads based on threadiness.  Some controllers have multiple kinds of workers
+	for i := 0; i < threadiness; i++ {
+		// runWorker will loop until "something bad" happens.  The .Until will then rekick the worker
+		// after one second
+		go wait.Until(c.runWorker, time.Second, stopCh)
+	}
+
+	// wait until we're told to stop
+	<-stopCh
+}
+
+func (c *autoRegisterController) runWorker() {
+	// hot loop until we're told to stop.  processNextWorkItem will automatically wait until there's work
+	// available, so we don't worry about secondary waits
+	for c.processNextWorkItem() {
+	}
+}
+
+// processNextWorkItem deals with one key off the queue.  It returns false when it's time to quit.
+func (c *autoRegisterController) processNextWorkItem() bool {
+	// pull the next work item from queue.  It should be a key we use to lookup something in a cache
+	key, quit := c.queue.Get()
+	if quit {
+		return false
+	}
+	// you always have to indicate to the queue that you've completed a piece of work
+	defer c.queue.Done(key)
+
+	// do your work on the key.  This method will contains your "do stuff" logic
+	err := c.syncHandler(key.(string))
+	if err == nil {
+		// if you had no error, tell the queue to stop tracking history for your key.  This will
+		// reset things like failure counts for per-item rate limiting
+		c.queue.Forget(key)
+		return true
+	}
+
+	// there was a failure so be sure to report it.  This method allows for pluggable error handling
+	// which can be used for things like cluster-monitoring
+	utilruntime.HandleError(fmt.Errorf("%v failed with : %v", key, err))
+	// since we failed, we should requeue the item to work on later.  This method will add a backoff
+	// to avoid hotlooping on particular items (they're probably still not going to work right away)
+	// and overall controller protection (everything I've done is broken, this controller needs to
+	// calm down or it can starve other useful work) cases.
+	c.queue.AddRateLimited(key)
+
+	return true
+}
+
+func (c *autoRegisterController) checkAPIService(name string) error {
+	desired := c.GetAPIServiceToSync(name)
+	curr, err := c.apiServiceLister.Get(name)
+
+	switch {
+	// we had a real error, just return it
+	case err != nil && !apierrors.IsNotFound(err):
+		return err
+
+	// we don't have an entry and we don't want one
+	case apierrors.IsNotFound(err) && desired == nil:
+		return nil
+
+	// we don't have an entry and we do want one
+	case apierrors.IsNotFound(err) && desired != nil:
+		_, err := c.apiServiceClient.APIServices().Create(desired)
+		return err
+
+	// we aren't trying to manage this APIService.  If the user removes the label, he's taken over management himself
+	case curr.Labels[AutoRegisterManagedLabel] != "true":
+		return nil
+
+	// we have a spurious APIService that we're managing, delete it
+	case desired == nil:
+		return c.apiServiceClient.APIServices().Delete(curr.Name, nil)
+
+	// if the specs already match, nothing for us to do
+	case reflect.DeepEqual(curr.Spec, desired.Spec):
+		return nil
+	}
+
+	// we have an entry and we have a desired, now we deconflict.  Only a few fields matter.
+	apiService := &apiregistration.APIService{}
+	if err := apiregistration.DeepCopy_apiregistration_APIService(curr, apiService, cloner); err != nil {
+		return err
+	}
+	apiService.Spec = desired.Spec
+	_, err = c.apiServiceClient.APIServices().Update(apiService)
+	return err
+}
+
+func (c *autoRegisterController) GetAPIServiceToSync(name string) *apiregistration.APIService {
+	c.apiServicesToSyncLock.RLock()
+	defer c.apiServicesToSyncLock.RUnlock()
+
+	return c.apiServicesToSync[name]
+}
+
+func (c *autoRegisterController) AddAPIServiceToSync(in *apiregistration.APIService) {
+	c.apiServicesToSyncLock.Lock()
+	defer c.apiServicesToSyncLock.Unlock()
+
+	apiService := &apiregistration.APIService{}
+	if err := apiregistration.DeepCopy_apiregistration_APIService(in, apiService, cloner); err != nil {
+		// this shouldn't happen
+		utilruntime.HandleError(err)
+		return
+	}
+	if apiService.Labels == nil {
+		apiService.Labels = map[string]string{}
+	}
+	apiService.Labels[AutoRegisterManagedLabel] = "true"
+
+	c.apiServicesToSync[apiService.Name] = apiService
+	c.queue.Add(apiService.Name)
+}
+
+func (c *autoRegisterController) RemoveAPIServiceToSync(name string) {
+	c.apiServicesToSyncLock.Lock()
+	defer c.apiServicesToSyncLock.Unlock()
+
+	delete(c.apiServicesToSync, name)
+	c.queue.Add(name)
+}

vendor/BUILD

@@ -16312,3 +16312,41 @@ filegroup(
     srcs = [":package-srcs"],
     tags = ["automanaged"],
 )
+
+go_test(
+    name = "k8s.io/kube-aggregator/pkg/controllers/autoregister_test",
+    srcs = ["k8s.io/kube-aggregator/pkg/controllers/autoregister/autoregister_controller_test.go"],
+    library = ":k8s.io/kube-aggregator/pkg/controllers/autoregister",
+    tags = ["automanaged"],
+    deps = [
+        "//vendor:k8s.io/apimachinery/pkg/api/errors",
+        "//vendor:k8s.io/apimachinery/pkg/api/meta",
+        "//vendor:k8s.io/apimachinery/pkg/apis/meta/v1",
+        "//vendor:k8s.io/apimachinery/pkg/util/wait",
+        "//vendor:k8s.io/apimachinery/pkg/watch",
+        "//vendor:k8s.io/client-go/testing",
+        "//vendor:k8s.io/kube-aggregator/pkg/apis/apiregistration",
+        "//vendor:k8s.io/kube-aggregator/pkg/client/clientset_generated/internalclientset",
+        "//vendor:k8s.io/kube-aggregator/pkg/client/clientset_generated/internalclientset/fake",
+        "//vendor:k8s.io/kube-aggregator/pkg/client/informers/internalversion",
+    ],
+)
+
+go_library(
+    name = "k8s.io/kube-aggregator/pkg/controllers/autoregister",
+    srcs = ["k8s.io/kube-aggregator/pkg/controllers/autoregister/autoregister_controller.go"],
+    tags = ["automanaged"],
+    deps = [
+        "//vendor:github.com/golang/glog",
+        "//vendor:k8s.io/apimachinery/pkg/api/errors",
+        "//vendor:k8s.io/apimachinery/pkg/conversion",
+        "//vendor:k8s.io/apimachinery/pkg/util/runtime",
+        "//vendor:k8s.io/apimachinery/pkg/util/wait",
+        "//vendor:k8s.io/client-go/tools/cache",
+        "//vendor:k8s.io/client-go/util/workqueue",
+        "//vendor:k8s.io/kube-aggregator/pkg/apis/apiregistration",
+        "//vendor:k8s.io/kube-aggregator/pkg/client/clientset_generated/internalclientset/typed/apiregistration/internalversion",
+        "//vendor:k8s.io/kube-aggregator/pkg/client/informers/internalversion/apiregistration/internalversion",
+        "//vendor:k8s.io/kube-aggregator/pkg/client/listers/apiregistration/internalversion",
+    ],
+)