resourcelock

Documentation

Index

• Constants
• func ConcatRawRecord(primaryRaw, secondaryRaw []byte) []byte
• func LeaderElectionRecordToLeaseSpec(ler *LeaderElectionRecord) coordinationv1.LeaseSpec
• type EventRecorder
• type Interface
  • func New(lockType string, ns string, name string, coreClient corev1.CoreV1Interface, ...) (Interface, error)
  • func NewFromKubeconfig(lockType string, ns string, name string, rlc ResourceLockConfig, ...) (Interface, error)
• type LeaderElectionRecord
  • func LeaseSpecToLeaderElectionRecord(spec *coordinationv1.LeaseSpec) *LeaderElectionRecord
• type LeaseLock
  • func (ll *LeaseLock) Create(ctx context.Context, ler LeaderElectionRecord) error
  • func (ll *LeaseLock) Describe() string
  • func (ll *LeaseLock) Get(ctx context.Context) (*LeaderElectionRecord, []byte, error)
  • func (ll *LeaseLock) Identity() string
  • func (ll *LeaseLock) RecordEvent(s string)
  • func (ll *LeaseLock) Update(ctx context.Context, ler LeaderElectionRecord) error
• type MultiLock
  • func (ml *MultiLock) Create(ctx context.Context, ler LeaderElectionRecord) error
  • func (ml *MultiLock) Describe() string
  • func (ml *MultiLock) Get(ctx context.Context) (*LeaderElectionRecord, []byte, error)
  • func (ml *MultiLock) Identity() string
  • func (ml *MultiLock) RecordEvent(s string)
  • func (ml *MultiLock) Update(ctx context.Context, ler LeaderElectionRecord) error
• type ResourceLockConfig

Constants

const (
	LeaderElectionRecordAnnotationKey = "control-plane.alpha.kubernetes.io/leader"

	LeasesResourceLock = "leases"
	// When using EndpointsLeasesResourceLock, you need to ensure that
	// API Priority & Fairness is configured with non-default flow-schema
	// that will catch the necessary operations on leader-election related
	// endpoint objects.
	//
	// The example of such flow scheme could look like this:
	//   apiVersion: flowcontrol.apiserver.k8s.io/v1beta2
	//   kind: FlowSchema
	//   metadata:
	//     name: my-leader-election
	//   spec:
	//     distinguisherMethod:
	//       type: ByUser
	//     matchingPrecedence: 200
	//     priorityLevelConfiguration:
	//       name: leader-election   # reference the <leader-election> PL
	//     rules:
	//     - resourceRules:
	//       - apiGroups:
	//         - ""
	//         namespaces:
	//         - '*'
	//         resources:
	//         - endpoints
	//         verbs:
	//         - get
	//         - create
	//         - update
	//       subjects:
	//       - kind: ServiceAccount
	//         serviceAccount:
	//           name: '*'
	//           namespace: kube-system
	EndpointsLeasesResourceLock = "endpointsleases"
	// When using EndpointsLeasesResourceLock, you need to ensure that
	// API Priority & Fairness is configured with non-default flow-schema
	// that will catch the necessary operations on leader-election related
	// configmap objects.
	//
	// The example of such flow scheme could look like this:
	//   apiVersion: flowcontrol.apiserver.k8s.io/v1beta2
	//   kind: FlowSchema
	//   metadata:
	//     name: my-leader-election
	//   spec:
	//     distinguisherMethod:
	//       type: ByUser
	//     matchingPrecedence: 200
	//     priorityLevelConfiguration:
	//       name: leader-election   # reference the <leader-election> PL
	//     rules:
	//     - resourceRules:
	//       - apiGroups:
	//         - ""
	//         namespaces:
	//         - '*'
	//         resources:
	//         - configmaps
	//         verbs:
	//         - get
	//         - create
	//         - update
	//       subjects:
	//       - kind: ServiceAccount
	//         serviceAccount:
	//           name: '*'
	//           namespace: kube-system
	ConfigMapsLeasesResourceLock = "configmapsleases"
)

const (
	UnknownLeader = "leaderelection.k8s.io/unknown"
)

Functions

func ConcatRawRecord

func ConcatRawRecord(primaryRaw, secondaryRaw []byte) []byte

func LeaderElectionRecordToLeaseSpec

func LeaderElectionRecordToLeaseSpec(ler *LeaderElectionRecord) coordinationv1.LeaseSpec

Types

type EventRecorder

type EventRecorder interface {
	Eventf(obj runtime.Object, eventType, reason, message string, args ...interface{})
}

EventRecorder records a change in the ResourceLock.

type Interface

type Interface interface {
	// Get returns the LeaderElectionRecord
	Get(ctx context.Context) (*LeaderElectionRecord, []byte, error)

	// Create attempts to create a LeaderElectionRecord
	Create(ctx context.Context, ler LeaderElectionRecord) error

	// Update will update and existing LeaderElectionRecord
	Update(ctx context.Context, ler LeaderElectionRecord) error

	// RecordEvent is used to record events
	RecordEvent(string)

	// Identity will return the locks Identity
	Identity() string

	// Describe is used to convert details on current resource lock
	// into a string
	Describe() string
}

Interface offers a common interface for locking on arbitrary resources used in leader election. The Interface is used to hide the details on specific implementations in order to allow them to change over time. This interface is strictly for use by the leaderelection code.

func New

func New(lockType string, ns string, name string, coreClient corev1.CoreV1Interface, coordinationClient coordinationv1.CoordinationV1Interface, rlc ResourceLockConfig) (Interface, error)

Manufacture will create a lock of a given type according to the input parameters

func NewFromKubeconfig

func NewFromKubeconfig(lockType string, ns string, name string, rlc ResourceLockConfig, kubeconfig *restclient.Config, renewDeadline time.Duration) (Interface, error)

NewFromKubeconfig will create a lock of a given type according to the input parameters. Timeout set for a client used to contact to Kubernetes should be lower than RenewDeadline to keep a single hung request from forcing a leader loss. Setting it to max(time.Second, RenewDeadline/2) as a reasonable heuristic.

type LeaderElectionRecord

type LeaderElectionRecord struct {
	// HolderIdentity is the ID that owns the lease. If empty, no one owns this lease and
	// all callers may acquire. Versions of this library prior to Kubernetes 1.14 will not
	// attempt to acquire leases with empty identities and will wait for the full lease
	// interval to expire before attempting to reacquire. This value is set to empty when
	// a client voluntarily steps down.
	HolderIdentity       string      `json:"holderIdentity"`
	LeaseDurationSeconds int         `json:"leaseDurationSeconds"`
	AcquireTime          metav1.Time `json:"acquireTime"`
	RenewTime            metav1.Time `json:"renewTime"`
	LeaderTransitions    int         `json:"leaderTransitions"`
}

LeaderElectionRecord is the record that is stored in the leader election annotation. This information should be used for observational purposes only and could be replaced with a random string (e.g. UUID) with only slight modification of this code. TODO(mikedanese): this should potentially be versioned

func LeaseSpecToLeaderElectionRecord

func LeaseSpecToLeaderElectionRecord(spec *coordinationv1.LeaseSpec) *LeaderElectionRecord

type LeaseLock

type LeaseLock struct {
	// LeaseMeta should contain a Name and a Namespace of a
	// LeaseMeta object that the LeaderElector will attempt to lead.
	LeaseMeta  metav1.ObjectMeta
	Client     coordinationv1client.LeasesGetter
	LockConfig ResourceLockConfig
	// contains filtered or unexported fields
}

func (*LeaseLock) Create

func (ll *LeaseLock) Create(ctx context.Context, ler LeaderElectionRecord) error

Create attempts to create a Lease

func (*LeaseLock) Describe

func (ll *LeaseLock) Describe() string

Describe is used to convert details on current resource lock into a string

func (*LeaseLock) Get

func (ll *LeaseLock) Get(ctx context.Context) (*LeaderElectionRecord, []byte, error)

Get returns the election record from a Lease spec

func (*LeaseLock) Identity

func (ll *LeaseLock) Identity() string

Identity returns the Identity of the lock

func (*LeaseLock) RecordEvent

func (ll *LeaseLock) RecordEvent(s string)

RecordEvent in leader election while adding meta-data

func (*LeaseLock) Update

func (ll *LeaseLock) Update(ctx context.Context, ler LeaderElectionRecord) error

Update will update an existing Lease spec.

type MultiLock

type MultiLock struct {
	Primary   Interface
	Secondary Interface
}

MultiLock is used for lock's migration

func (*MultiLock) Create

func (ml *MultiLock) Create(ctx context.Context, ler LeaderElectionRecord) error

Create attempts to create both primary lock and secondary lock

func (*MultiLock) Describe

func (ml *MultiLock) Describe() string

Describe is used to convert details on current resource lock into a string

func (*MultiLock) Get

func (ml *MultiLock) Get(ctx context.Context) (*LeaderElectionRecord, []byte, error)

Get returns the older election record of the lock

func (*MultiLock) Identity

func (ml *MultiLock) Identity() string

Identity returns the Identity of the lock

func (*MultiLock) RecordEvent

func (ml *MultiLock) RecordEvent(s string)

RecordEvent in leader election while adding meta-data

func (*MultiLock) Update

func (ml *MultiLock) Update(ctx context.Context, ler LeaderElectionRecord) error

Update will update and existing annotation on both two resources.

type ResourceLockConfig

type ResourceLockConfig struct {
	// Identity is the unique string identifying a lease holder across
	// all participants in an election.
	Identity string
	// EventRecorder is optional.
	EventRecorder EventRecorder
}

ResourceLockConfig common data that exists across different resource locks