README
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internal/leader
Logic overview
The leader package provides leadership-event orchestration primitives used to drive leader/follower runtime behavior.
Electoris the abstraction for any leader-election backend (Kubernetes Lease, static mode, test feed).Runnerconverts election callbacks into role and error channels for consumers like runtime role managers.- Role transitions are deduplicated to avoid repeated
leader -> leaderorfollower -> followerchurn. - Context cancellation is treated as normal shutdown and not surfaced as an error.
KubernetesLeaseElectorperforms lease create/renew/takeover decisions directly through Kubernetes coordination API Lease resources.
API reference
Types
Elector: backend contract that emits role transitions.Runner: wraps anElectorand exposes role/error channels.StaticElector: emits a fixed role and waits for context cancellation.ChannelElector: emits role transitions from a channel.KubernetesLeaseConfig: configuration for Lease API endpoint, identity, timing, and HTTP client behavior.KubernetesLeaseElector: Lease-backed elector implementation.
Functions
NewRunner(elector Elector, logger ...*zap.Logger) *Runner: creates a runner with optional zap logger.NewKubernetesLeaseElector(cfg KubernetesLeaseConfig) (*KubernetesLeaseElector, error): creates a Lease-backed elector.
Methods
(*Runner) Start(ctx context.Context) (<-chan bool, <-chan error): starts election observation and returns deduplicated role transitions plus fatal election errors.(StaticElector) Run(ctx context.Context, emit func(isLeader bool)) error: emits the configured role once.(ChannelElector) Run(ctx context.Context, emit func(isLeader bool)) error: relays events fromEventsuntil close or cancellation.(*KubernetesLeaseElector) Run(ctx context.Context, emit func(isLeader bool)) error: periodically acquires/renews the configured Lease and emits leadership state.(*KubernetesLeaseElector) TryAcquireOrRenew(ctx context.Context) (bool, error): executes one Lease acquisition/renewal decision.
Documentation
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Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type ChannelElector ¶
ChannelElector emits role events from an input channel.
type KubernetesLeaseConfig ¶
type KubernetesLeaseConfig struct {
APIBaseURL string
Namespace string
LeaseName string
Identity string
//nolint:gosec // Bearer token is required for Kubernetes API authentication.
BearerToken string
LeaseDuration time.Duration
RetryPeriod time.Duration
HTTPClient *http.Client
Now func() time.Time
Sleep func(time.Duration)
}
KubernetesLeaseConfig configures Kubernetes Lease-based election.
type KubernetesLeaseElector ¶
type KubernetesLeaseElector struct {
// contains filtered or unexported fields
}
KubernetesLeaseElector implements leader election with coordination.k8s.io Lease resources.
func NewKubernetesLeaseElector ¶
func NewKubernetesLeaseElector(cfg KubernetesLeaseConfig) (*KubernetesLeaseElector, error)
NewKubernetesLeaseElector creates a Kubernetes Lease elector.
func (*KubernetesLeaseElector) Run ¶
func (e *KubernetesLeaseElector) Run(ctx context.Context, emit func(isLeader bool)) error
Run evaluates lease ownership in a retry loop and emits leadership state.
func (*KubernetesLeaseElector) TryAcquireOrRenew ¶
func (e *KubernetesLeaseElector) TryAcquireOrRenew(ctx context.Context) (bool, error)
TryAcquireOrRenew attempts to create, renew, or take over the configured lease.
type Runner ¶
type Runner struct {
// contains filtered or unexported fields
}
Runner adapts an Elector into role and error channels used by runtime orchestration.
type StaticElector ¶
type StaticElector struct {
IsLeader bool
}
StaticElector emits a fixed role and then waits for context cancellation.
Source Files