Vendor main dependencies.

vendor/k8s.io/client-go/1.5/tools/cache/reflector.go

@@ -0,0 +1,419 @@
+/*
+Copyright 2014 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 cache
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"math/rand"
+	"net"
+	"net/url"
+	"reflect"
+	"regexp"
+	goruntime "runtime"
+	"runtime/debug"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+
+	"github.com/golang/glog"
+	"k8s.io/client-go/1.5/pkg/api"
+	apierrs "k8s.io/client-go/1.5/pkg/api/errors"
+	"k8s.io/client-go/1.5/pkg/api/meta"
+	"k8s.io/client-go/1.5/pkg/runtime"
+	utilruntime "k8s.io/client-go/1.5/pkg/util/runtime"
+	"k8s.io/client-go/1.5/pkg/util/wait"
+	"k8s.io/client-go/1.5/pkg/watch"
+)
+
+// ListerWatcher is any object that knows how to perform an initial list and start a watch on a resource.
+type ListerWatcher interface {
+	// List should return a list type object; the Items field will be extracted, and the
+	// ResourceVersion field will be used to start the watch in the right place.
+	List(options api.ListOptions) (runtime.Object, error)
+	// Watch should begin a watch at the specified version.
+	Watch(options api.ListOptions) (watch.Interface, error)
+}
+
+// Reflector watches a specified resource and causes all changes to be reflected in the given store.
+type Reflector struct {
+	// name identifies this reflector.  By default it will be a file:line if possible.
+	name string
+
+	// The type of object we expect to place in the store.
+	expectedType reflect.Type
+	// The destination to sync up with the watch source
+	store Store
+	// listerWatcher is used to perform lists and watches.
+	listerWatcher ListerWatcher
+	// period controls timing between one watch ending and
+	// the beginning of the next one.
+	period       time.Duration
+	resyncPeriod time.Duration
+	// now() returns current time - exposed for testing purposes
+	now func() time.Time
+	// lastSyncResourceVersion is the resource version token last
+	// observed when doing a sync with the underlying store
+	// it is thread safe, but not synchronized with the underlying store
+	lastSyncResourceVersion string
+	// lastSyncResourceVersionMutex guards read/write access to lastSyncResourceVersion
+	lastSyncResourceVersionMutex sync.RWMutex
+}
+
+var (
+	// We try to spread the load on apiserver by setting timeouts for
+	// watch requests - it is random in [minWatchTimeout, 2*minWatchTimeout].
+	// However, it can be modified to avoid periodic resync to break the
+	// TCP connection.
+	minWatchTimeout = 5 * time.Minute
+	// If we are within 'forceResyncThreshold' from the next planned resync
+	// and are just before issuing Watch(), resync will be forced now.
+	forceResyncThreshold = 3 * time.Second
+	// We try to set timeouts for Watch() so that we will finish about
+	// than 'timeoutThreshold' from next planned periodic resync.
+	timeoutThreshold = 1 * time.Second
+)
+
+// NewNamespaceKeyedIndexerAndReflector creates an Indexer and a Reflector
+// The indexer is configured to key on namespace
+func NewNamespaceKeyedIndexerAndReflector(lw ListerWatcher, expectedType interface{}, resyncPeriod time.Duration) (indexer Indexer, reflector *Reflector) {
+	indexer = NewIndexer(MetaNamespaceKeyFunc, Indexers{"namespace": MetaNamespaceIndexFunc})
+	reflector = NewReflector(lw, expectedType, indexer, resyncPeriod)
+	return indexer, reflector
+}
+
+// NewReflector creates a new Reflector object which will keep the given store up to
+// date with the server's contents for the given resource. Reflector promises to
+// only put things in the store that have the type of expectedType, unless expectedType
+// is nil. If resyncPeriod is non-zero, then lists will be executed after every
+// resyncPeriod, so that you can use reflectors to periodically process everything as
+// well as incrementally processing the things that change.
+func NewReflector(lw ListerWatcher, expectedType interface{}, store Store, resyncPeriod time.Duration) *Reflector {
+	return NewNamedReflector(getDefaultReflectorName(internalPackages...), lw, expectedType, store, resyncPeriod)
+}
+
+// NewNamedReflector same as NewReflector, but with a specified name for logging
+func NewNamedReflector(name string, lw ListerWatcher, expectedType interface{}, store Store, resyncPeriod time.Duration) *Reflector {
+	r := &Reflector{
+		name:          name,
+		listerWatcher: lw,
+		store:         store,
+		expectedType:  reflect.TypeOf(expectedType),
+		period:        time.Second,
+		resyncPeriod:  resyncPeriod,
+		now:           time.Now,
+	}
+	return r
+}
+
+// internalPackages are packages that ignored when creating a default reflector name.  These packages are in the common
+// call chains to NewReflector, so they'd be low entropy names for reflectors
+var internalPackages = []string{"kubernetes/pkg/client/cache/", "kubernetes/pkg/controller/framework/", "/runtime/asm_"}
+
+// getDefaultReflectorName walks back through the call stack until we find a caller from outside of the ignoredPackages
+// it returns back a shortpath/filename:line to aid in identification of this reflector when it starts logging
+func getDefaultReflectorName(ignoredPackages ...string) string {
+	name := "????"
+	const maxStack = 10
+	for i := 1; i < maxStack; i++ {
+		_, file, line, ok := goruntime.Caller(i)
+		if !ok {
+			file, line, ok = extractStackCreator()
+			if !ok {
+				break
+			}
+			i += maxStack
+		}
+		if hasPackage(file, ignoredPackages) {
+			continue
+		}
+
+		file = trimPackagePrefix(file)
+		name = fmt.Sprintf("%s:%d", file, line)
+		break
+	}
+	return name
+}
+
+// hasPackage returns true if the file is in one of the ignored packages.
+func hasPackage(file string, ignoredPackages []string) bool {
+	for _, ignoredPackage := range ignoredPackages {
+		if strings.Contains(file, ignoredPackage) {
+			return true
+		}
+	}
+	return false
+}
+
+// trimPackagePrefix reduces duplicate values off the front of a package name.
+func trimPackagePrefix(file string) string {
+	if l := strings.LastIndex(file, "k8s.io/client-go/1.5/pkg/"); l >= 0 {
+		return file[l+len("k8s.io/client-go/1.5/"):]
+	}
+	if l := strings.LastIndex(file, "/src/"); l >= 0 {
+		return file[l+5:]
+	}
+	if l := strings.LastIndex(file, "/pkg/"); l >= 0 {
+		return file[l+1:]
+	}
+	return file
+}
+
+var stackCreator = regexp.MustCompile(`(?m)^created by (.*)\n\s+(.*):(\d+) \+0x[[:xdigit:]]+$`)
+
+// extractStackCreator retrieves the goroutine file and line that launched this stack. Returns false
+// if the creator cannot be located.
+// TODO: Go does not expose this via runtime https://github.com/golang/go/issues/11440
+func extractStackCreator() (string, int, bool) {
+	stack := debug.Stack()
+	matches := stackCreator.FindStringSubmatch(string(stack))
+	if matches == nil || len(matches) != 4 {
+		return "", 0, false
+	}
+	line, err := strconv.Atoi(matches[3])
+	if err != nil {
+		return "", 0, false
+	}
+	return matches[2], line, true
+}
+
+// Run starts a watch and handles watch events. Will restart the watch if it is closed.
+// Run starts a goroutine and returns immediately.
+func (r *Reflector) Run() {
+	glog.V(3).Infof("Starting reflector %v (%s) from %s", r.expectedType, r.resyncPeriod, r.name)
+	go wait.Until(func() {
+		if err := r.ListAndWatch(wait.NeverStop); err != nil {
+			utilruntime.HandleError(err)
+		}
+	}, r.period, wait.NeverStop)
+}
+
+// RunUntil starts a watch and handles watch events. Will restart the watch if it is closed.
+// RunUntil starts a goroutine and returns immediately. It will exit when stopCh is closed.
+func (r *Reflector) RunUntil(stopCh <-chan struct{}) {
+	glog.V(3).Infof("Starting reflector %v (%s) from %s", r.expectedType, r.resyncPeriod, r.name)
+	go wait.Until(func() {
+		if err := r.ListAndWatch(stopCh); err != nil {
+			utilruntime.HandleError(err)
+		}
+	}, r.period, stopCh)
+}
+
+var (
+	// nothing will ever be sent down this channel
+	neverExitWatch <-chan time.Time = make(chan time.Time)
+
+	// Used to indicate that watching stopped so that a resync could happen.
+	errorResyncRequested = errors.New("resync channel fired")
+
+	// Used to indicate that watching stopped because of a signal from the stop
+	// channel passed in from a client of the reflector.
+	errorStopRequested = errors.New("Stop requested")
+)
+
+// resyncChan returns a channel which will receive something when a resync is
+// required, and a cleanup function.
+func (r *Reflector) resyncChan() (<-chan time.Time, func() bool) {
+	if r.resyncPeriod == 0 {
+		return neverExitWatch, func() bool { return false }
+	}
+	// The cleanup function is required: imagine the scenario where watches
+	// always fail so we end up listing frequently. Then, if we don't
+	// manually stop the timer, we could end up with many timers active
+	// concurrently.
+	t := time.NewTimer(r.resyncPeriod)
+	return t.C, t.Stop
+}
+
+// ListAndWatch first lists all items and get the resource version at the moment of call,
+// and then use the resource version to watch.
+// It returns error if ListAndWatch didn't even try to initialize watch.
+func (r *Reflector) ListAndWatch(stopCh <-chan struct{}) error {
+	glog.V(3).Infof("Listing and watching %v from %s", r.expectedType, r.name)
+	var resourceVersion string
+	resyncCh, cleanup := r.resyncChan()
+	defer cleanup()
+
+	// Explicitly set "0" as resource version - it's fine for the List()
+	// to be served from cache and potentially be delayed relative to
+	// etcd contents. Reflector framework will catch up via Watch() eventually.
+	options := api.ListOptions{ResourceVersion: "0"}
+	list, err := r.listerWatcher.List(options)
+	if err != nil {
+		return fmt.Errorf("%s: Failed to list %v: %v", r.name, r.expectedType, err)
+	}
+	listMetaInterface, err := meta.ListAccessor(list)
+	if err != nil {
+		return fmt.Errorf("%s: Unable to understand list result %#v: %v", r.name, list, err)
+	}
+	resourceVersion = listMetaInterface.GetResourceVersion()
+	items, err := meta.ExtractList(list)
+	if err != nil {
+		return fmt.Errorf("%s: Unable to understand list result %#v (%v)", r.name, list, err)
+	}
+	if err := r.syncWith(items, resourceVersion); err != nil {
+		return fmt.Errorf("%s: Unable to sync list result: %v", r.name, err)
+	}
+	r.setLastSyncResourceVersion(resourceVersion)
+
+	resyncerrc := make(chan error, 1)
+	go func() {
+		for {
+			select {
+			case <-resyncCh:
+			case <-stopCh:
+				return
+			}
+			glog.V(4).Infof("%s: forcing resync", r.name)
+			if err := r.store.Resync(); err != nil {
+				resyncerrc <- err
+				return
+			}
+			cleanup()
+			resyncCh, cleanup = r.resyncChan()
+		}
+	}()
+
+	for {
+		timemoutseconds := int64(minWatchTimeout.Seconds() * (rand.Float64() + 1.0))
+		options = api.ListOptions{
+			ResourceVersion: resourceVersion,
+			// We want to avoid situations of hanging watchers. Stop any wachers that do not
+			// receive any events within the timeout window.
+			TimeoutSeconds: &timemoutseconds,
+		}
+
+		w, err := r.listerWatcher.Watch(options)
+		if err != nil {
+			switch err {
+			case io.EOF:
+				// watch closed normally
+			case io.ErrUnexpectedEOF:
+				glog.V(1).Infof("%s: Watch for %v closed with unexpected EOF: %v", r.name, r.expectedType, err)
+			default:
+				utilruntime.HandleError(fmt.Errorf("%s: Failed to watch %v: %v", r.name, r.expectedType, err))
+			}
+			// If this is "connection refused" error, it means that most likely apiserver is not responsive.
+			// It doesn't make sense to re-list all objects because most likely we will be able to restart
+			// watch where we ended.
+			// If that's the case wait and resend watch request.
+			if urlError, ok := err.(*url.Error); ok {
+				if opError, ok := urlError.Err.(*net.OpError); ok {
+					if errno, ok := opError.Err.(syscall.Errno); ok && errno == syscall.ECONNREFUSED {
+						time.Sleep(time.Second)
+						continue
+					}
+				}
+			}
+			return nil
+		}
+
+		if err := r.watchHandler(w, &resourceVersion, resyncerrc, stopCh); err != nil {
+			if err != errorStopRequested {
+				glog.Warningf("%s: watch of %v ended with: %v", r.name, r.expectedType, err)
+			}
+			return nil
+		}
+	}
+}
+
+// syncWith replaces the store's items with the given list.
+func (r *Reflector) syncWith(items []runtime.Object, resourceVersion string) error {
+	found := make([]interface{}, 0, len(items))
+	for _, item := range items {
+		found = append(found, item)
+	}
+	return r.store.Replace(found, resourceVersion)
+}
+
+// watchHandler watches w and keeps *resourceVersion up to date.
+func (r *Reflector) watchHandler(w watch.Interface, resourceVersion *string, errc chan error, stopCh <-chan struct{}) error {
+	start := time.Now()
+	eventCount := 0
+
+	// Stopping the watcher should be idempotent and if we return from this function there's no way
+	// we're coming back in with the same watch interface.
+	defer w.Stop()
+
+loop:
+	for {
+		select {
+		case <-stopCh:
+			return errorStopRequested
+		case err := <-errc:
+			return err
+		case event, ok := <-w.ResultChan():
+			if !ok {
+				break loop
+			}
+			if event.Type == watch.Error {
+				return apierrs.FromObject(event.Object)
+			}
+			if e, a := r.expectedType, reflect.TypeOf(event.Object); e != nil && e != a {
+				utilruntime.HandleError(fmt.Errorf("%s: expected type %v, but watch event object had type %v", r.name, e, a))
+				continue
+			}
+			meta, err := meta.Accessor(event.Object)
+			if err != nil {
+				utilruntime.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
+				continue
+			}
+			newResourceVersion := meta.GetResourceVersion()
+			switch event.Type {
+			case watch.Added:
+				r.store.Add(event.Object)
+			case watch.Modified:
+				r.store.Update(event.Object)
+			case watch.Deleted:
+				// TODO: Will any consumers need access to the "last known
+				// state", which is passed in event.Object? If so, may need
+				// to change this.
+				r.store.Delete(event.Object)
+			default:
+				utilruntime.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", r.name, event))
+			}
+			*resourceVersion = newResourceVersion
+			r.setLastSyncResourceVersion(newResourceVersion)
+			eventCount++
+		}
+	}
+
+	watchDuration := time.Now().Sub(start)
+	if watchDuration < 1*time.Second && eventCount == 0 {
+		glog.V(4).Infof("%s: Unexpected watch close - watch lasted less than a second and no items received", r.name)
+		return errors.New("very short watch")
+	}
+	glog.V(4).Infof("%s: Watch close - %v total %v items received", r.name, r.expectedType, eventCount)
+	return nil
+}
+
+// LastSyncResourceVersion is the resource version observed when last sync with the underlying store
+// The value returned is not synchronized with access to the underlying store and is not thread-safe
+func (r *Reflector) LastSyncResourceVersion() string {
+	r.lastSyncResourceVersionMutex.RLock()
+	defer r.lastSyncResourceVersionMutex.RUnlock()
+	return r.lastSyncResourceVersion
+}
+
+func (r *Reflector) setLastSyncResourceVersion(v string) {
+	r.lastSyncResourceVersionMutex.Lock()
+	defer r.lastSyncResourceVersionMutex.Unlock()
+	r.lastSyncResourceVersion = v
+}