| /* |
| Copyright 2019 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 k8sresourcelock |
| |
| import ( |
| "bytes" |
| "context" |
| "encoding/json" |
| ) |
| |
| import ( |
| apierrors "k8s.io/apimachinery/pkg/api/errors" |
| ) |
| |
| const ( |
| UnknownLeader = "leaderelection.k8s.io/unknown" |
| ) |
| |
| // MultiLock is used for lock's migration |
| type MultiLock struct { |
| Primary Interface |
| Secondary Interface |
| } |
| |
| // Get returns the older election record of the lock |
| func (ml *MultiLock) Get(ctx context.Context) (*LeaderElectionRecord, []byte, error) { |
| primary, primaryRaw, err := ml.Primary.Get(ctx) |
| if err != nil { |
| return nil, nil, err |
| } |
| |
| secondary, secondaryRaw, err := ml.Secondary.Get(ctx) |
| if err != nil { |
| // Lock is held by old client |
| if apierrors.IsNotFound(err) && primary.HolderIdentity != ml.Identity() { |
| return primary, primaryRaw, nil |
| } |
| return nil, nil, err |
| } |
| |
| if primary.HolderIdentity != secondary.HolderIdentity { |
| primary.HolderIdentity = UnknownLeader |
| primaryRaw, err = json.Marshal(primary) |
| if err != nil { |
| return nil, nil, err |
| } |
| } |
| return primary, ConcatRawRecord(primaryRaw, secondaryRaw), nil |
| } |
| |
| // Create attempts to create both primary lock and secondary lock |
| func (ml *MultiLock) Create(ctx context.Context, ler LeaderElectionRecord) error { |
| err := ml.Primary.Create(ctx, ler) |
| if err != nil && !apierrors.IsAlreadyExists(err) { |
| return err |
| } |
| return ml.Secondary.Create(ctx, ler) |
| } |
| |
| // Update will update and existing annotation on both two resources. |
| func (ml *MultiLock) Update(ctx context.Context, ler LeaderElectionRecord) error { |
| err := ml.Primary.Update(ctx, ler) |
| if err != nil { |
| return err |
| } |
| _, _, err = ml.Secondary.Get(ctx) |
| if err != nil && apierrors.IsNotFound(err) { |
| return ml.Secondary.Create(ctx, ler) |
| } |
| return ml.Secondary.Update(ctx, ler) |
| } |
| |
| // RecordEvent in leader election while adding meta-data |
| func (ml *MultiLock) RecordEvent(s string) { |
| ml.Primary.RecordEvent(s) |
| ml.Secondary.RecordEvent(s) |
| } |
| |
| // Describe is used to convert details on current resource lock |
| // into a string |
| func (ml *MultiLock) Describe() string { |
| return ml.Primary.Describe() |
| } |
| |
| // Identity returns the Identity of the lock |
| func (ml *MultiLock) Identity() string { |
| return ml.Primary.Identity() |
| } |
| |
| // Key returns the Key of the lock |
| func (ml *MultiLock) Key() string { |
| return ml.Primary.Key() |
| } |
| |
| func ConcatRawRecord(primaryRaw, secondaryRaw []byte) []byte { |
| return bytes.Join([][]byte{primaryRaw, secondaryRaw}, []byte(",")) |
| } |