mirror of https://github.com/k3s-io/k3s
127 lines
4.2 KiB
Go
127 lines
4.2 KiB
Go
/*
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Copyright 2016 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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"fmt"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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"k8s.io/apimachinery/pkg/runtime"
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coordinationv1 "k8s.io/client-go/kubernetes/typed/coordination/v1"
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corev1 "k8s.io/client-go/kubernetes/typed/core/v1"
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)
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const (
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LeaderElectionRecordAnnotationKey = "control-plane.alpha.kubernetes.io/leader"
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EndpointsResourceLock = "endpoints"
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ConfigMapsResourceLock = "configmaps"
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LeasesResourceLock = "leases"
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)
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// LeaderElectionRecord is the record that is stored in the leader election annotation.
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// This information should be used for observational purposes only and could be replaced
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// with a random string (e.g. UUID) with only slight modification of this code.
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// TODO(mikedanese): this should potentially be versioned
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type LeaderElectionRecord struct {
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// HolderIdentity is the ID that owns the lease. If empty, no one owns this lease and
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// all callers may acquire. Versions of this library prior to Kubernetes 1.14 will not
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// attempt to acquire leases with empty identities and will wait for the full lease
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// interval to expire before attempting to reacquire. This value is set to empty when
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// a client voluntarily steps down.
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HolderIdentity string `json:"holderIdentity"`
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LeaseDurationSeconds int `json:"leaseDurationSeconds"`
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AcquireTime metav1.Time `json:"acquireTime"`
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RenewTime metav1.Time `json:"renewTime"`
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LeaderTransitions int `json:"leaderTransitions"`
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}
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// EventRecorder records a change in the ResourceLock.
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type EventRecorder interface {
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Eventf(obj runtime.Object, eventType, reason, message string, args ...interface{})
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}
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// ResourceLockConfig common data that exists across different
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// resource locks
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type ResourceLockConfig struct {
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// Identity is the unique string identifying a lease holder across
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// all participants in an election.
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Identity string
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// EventRecorder is optional.
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EventRecorder EventRecorder
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}
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// Interface offers a common interface for locking on arbitrary
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// resources used in leader election. The Interface is used
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// to hide the details on specific implementations in order to allow
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// them to change over time. This interface is strictly for use
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// by the leaderelection code.
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type Interface interface {
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// Get returns the LeaderElectionRecord
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Get() (*LeaderElectionRecord, error)
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// Create attempts to create a LeaderElectionRecord
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Create(ler LeaderElectionRecord) error
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// Update will update and existing LeaderElectionRecord
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Update(ler LeaderElectionRecord) error
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// RecordEvent is used to record events
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RecordEvent(string)
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// Identity will return the locks Identity
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Identity() string
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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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Describe() string
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}
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// Manufacture will create a lock of a given type according to the input parameters
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func New(lockType string, ns string, name string, coreClient corev1.CoreV1Interface, coordinationClient coordinationv1.CoordinationV1Interface, rlc ResourceLockConfig) (Interface, error) {
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switch lockType {
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case EndpointsResourceLock:
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return &EndpointsLock{
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EndpointsMeta: metav1.ObjectMeta{
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Namespace: ns,
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Name: name,
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},
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Client: coreClient,
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LockConfig: rlc,
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}, nil
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case ConfigMapsResourceLock:
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return &ConfigMapLock{
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ConfigMapMeta: metav1.ObjectMeta{
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Namespace: ns,
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Name: name,
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},
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Client: coreClient,
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LockConfig: rlc,
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}, nil
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case LeasesResourceLock:
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return &LeaseLock{
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LeaseMeta: metav1.ObjectMeta{
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Namespace: ns,
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Name: name,
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},
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Client: coordinationClient,
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LockConfig: rlc,
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}, nil
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default:
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return nil, fmt.Errorf("Invalid lock-type %s", lockType)
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}
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}
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