mirror of https://github.com/k3s-io/k3s
110 lines
3.5 KiB
Go
110 lines
3.5 KiB
Go
/*
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Copyright 2017 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package resourcelock
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import (
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"encoding/json"
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"errors"
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"fmt"
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"k8s.io/api/core/v1"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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corev1client "k8s.io/client-go/kubernetes/typed/core/v1"
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)
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// TODO: This is almost a exact replica of Endpoints lock.
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// going forwards as we self host more and more components
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// and use ConfigMaps as the means to pass that configuration
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// data we will likely move to deprecate the Endpoints lock.
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type ConfigMapLock struct {
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// ConfigMapMeta should contain a Name and a Namespace of a
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// ConfigMapMeta object that the LeaderElector will attempt to lead.
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ConfigMapMeta metav1.ObjectMeta
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Client corev1client.ConfigMapsGetter
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LockConfig ResourceLockConfig
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cm *v1.ConfigMap
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}
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// Get returns the election record from a ConfigMap Annotation
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func (cml *ConfigMapLock) Get() (*LeaderElectionRecord, error) {
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var record LeaderElectionRecord
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var err error
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cml.cm, err = cml.Client.ConfigMaps(cml.ConfigMapMeta.Namespace).Get(cml.ConfigMapMeta.Name, metav1.GetOptions{})
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if err != nil {
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return nil, err
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}
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if cml.cm.Annotations == nil {
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cml.cm.Annotations = make(map[string]string)
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}
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if recordBytes, found := cml.cm.Annotations[LeaderElectionRecordAnnotationKey]; found {
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if err := json.Unmarshal([]byte(recordBytes), &record); err != nil {
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return nil, err
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}
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}
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return &record, nil
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}
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// Create attempts to create a LeaderElectionRecord annotation
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func (cml *ConfigMapLock) Create(ler LeaderElectionRecord) error {
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recordBytes, err := json.Marshal(ler)
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if err != nil {
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return err
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}
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cml.cm, err = cml.Client.ConfigMaps(cml.ConfigMapMeta.Namespace).Create(&v1.ConfigMap{
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ObjectMeta: metav1.ObjectMeta{
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Name: cml.ConfigMapMeta.Name,
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Namespace: cml.ConfigMapMeta.Namespace,
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Annotations: map[string]string{
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LeaderElectionRecordAnnotationKey: string(recordBytes),
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},
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},
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})
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return err
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}
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// Update will update an existing annotation on a given resource.
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func (cml *ConfigMapLock) Update(ler LeaderElectionRecord) error {
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if cml.cm == nil {
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return errors.New("configmap not initialized, call get or create first")
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}
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recordBytes, err := json.Marshal(ler)
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if err != nil {
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return err
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}
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cml.cm.Annotations[LeaderElectionRecordAnnotationKey] = string(recordBytes)
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cml.cm, err = cml.Client.ConfigMaps(cml.ConfigMapMeta.Namespace).Update(cml.cm)
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return err
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}
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// RecordEvent in leader election while adding meta-data
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func (cml *ConfigMapLock) RecordEvent(s string) {
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events := fmt.Sprintf("%v %v", cml.LockConfig.Identity, s)
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cml.LockConfig.EventRecorder.Eventf(&v1.ConfigMap{ObjectMeta: cml.cm.ObjectMeta}, v1.EventTypeNormal, "LeaderElection", events)
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}
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// Describe is used to convert details on current resource lock
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// into a string
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func (cml *ConfigMapLock) Describe() string {
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return fmt.Sprintf("%v/%v", cml.ConfigMapMeta.Namespace, cml.ConfigMapMeta.Name)
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}
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// returns the Identity of the lock
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func (cml *ConfigMapLock) Identity() string {
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return cml.LockConfig.Identity
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}
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