mirror of https://github.com/knative/pkg.git
50 lines
1.9 KiB
Go
50 lines
1.9 KiB
Go
/*
|
|
Copyright 2018 The Knative 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 configmap
|
|
|
|
import (
|
|
corev1 "k8s.io/api/core/v1"
|
|
)
|
|
|
|
// Observer is the signature of the callbacks that notify an observer of the latest
|
|
// state of a particular configuration. An observer should not modify the provided
|
|
// ConfigMap, and should `.DeepCopy()` it for persistence (or otherwise process its
|
|
// contents).
|
|
type Observer func(*corev1.ConfigMap)
|
|
|
|
// Watcher defines the interface that a configmap implementation must implement.
|
|
type Watcher interface {
|
|
// Watch is called to register callbacks to be notified when a named ConfigMap changes.
|
|
Watch(string, ...Observer)
|
|
|
|
// Start is called to initiate the watches and provide a channel to signal when we should
|
|
// stop watching. When Start returns, all registered Observers will be called with the
|
|
// initial state of the ConfigMaps they are watching.
|
|
Start(<-chan struct{}) error
|
|
}
|
|
|
|
// DefaultingWatcher is similar to Watcher, but if a ConfigMap is absent, then a code provided
|
|
// default will be used.
|
|
type DefaultingWatcher interface {
|
|
Watcher
|
|
|
|
// WatchWithDefault is called to register callbacks to be notified when a named ConfigMap
|
|
// changes. The provided default value is always observed before any real ConfigMap with that
|
|
// name is. If the real ConfigMap with that name is deleted, then the default value is observed.
|
|
WatchWithDefault(cm corev1.ConfigMap, o ...Observer)
|
|
}
|