Factor out etcdWatcher to a separate file

docs/proposals/apiserver_watch.md

@@ -163,7 +163,7 @@ resource type. However, this watch can potentially expire at any time and
 reconnecting can return "too old resource version". In that case relisting is
 necessary. In such case, to avoid LIST requests coming from all watchers at
 the same time, we can introduce an additional etcd event type:
-[EtcdResync](../../pkg/tools/etcd_helper_watch.go#L36)
+[EtcdResync](../../pkg/tools/etcd_watcher.go#L36)
 
   Whenever reslisting will be done to refresh the internal watch to etcd,
   EtcdResync event will be send to all the watchers. It will contain the

pkg/tools/etcd_helper.go

@@ -29,6 +29,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/tools/metrics"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/watch"
 	"github.com/coreos/go-etcd/etcd"
 
 	"github.com/golang/glog"
@@ -176,6 +177,22 @@ func (h *etcdHelper) Delete(key string, recursive bool) error {
 	return err
 }
 
+// Implements StorageInterface.
+func (h *etcdHelper) Watch(key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error) {
+	key = h.prefixEtcdKey(key)
+	w := newEtcdWatcher(false, nil, filter, h.codec, h.versioner, nil, h)
+	go w.etcdWatch(h.client, key, resourceVersion)
+	return w, nil
+}
+
+// Implements StorageInterface.
+func (h *etcdHelper) WatchList(key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error) {
+	key = h.prefixEtcdKey(key)
+	w := newEtcdWatcher(true, exceptKey(key), filter, h.codec, h.versioner, nil, h)
+	go w.etcdWatch(h.client, key, resourceVersion)
+	return w, nil
+}
+
 // Implements StorageInterface.
 func (h *etcdHelper) ExtractObj(key string, objPtr runtime.Object, ignoreNotFound bool) error {
 	key = h.prefixEtcdKey(key)

pkg/tools/etcd_watcher.go

@@ -66,27 +66,6 @@ func ParseWatchResourceVersion(resourceVersion, kind string) (uint64, error) {
 	return version + 1, nil
 }
 
-// WatchList begins watching the specified key's items. Items are decoded into
-// API objects, and any items passing 'filter' are sent down the returned
-// watch.Interface. resourceVersion may be used to specify what version to begin
-// watching (e.g., for reconnecting without missing any updates).
-func (h *etcdHelper) WatchList(key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error) {
-	key = h.prefixEtcdKey(key)
-	w := newEtcdWatcher(true, exceptKey(key), filter, h.codec, h.versioner, nil, h)
-	go w.etcdWatch(h.client, key, resourceVersion)
-	return w, nil
-}
-
-// Watch begins watching the specified key. Events are decoded into
-// API objects and sent down the returned watch.Interface.
-// Errors will be sent down the channel.
-func (h *etcdHelper) Watch(key string, resourceVersion uint64, filter FilterFunc) (watch.Interface, error) {
-	key = h.prefixEtcdKey(key)
-	w := newEtcdWatcher(false, nil, filter, h.codec, h.versioner, nil, h)
-	go w.etcdWatch(h.client, key, resourceVersion)
-	return w, nil
-}
-
 // TransformFunc attempts to convert an object to another object for use with a watcher.
 type TransformFunc func(runtime.Object) (runtime.Object, error)