README
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pkg/konductor
konductor wraps Kubernetes leader election so that only one Orkestra runtime pod processes reconcile events at a time. When a pod wins the election it becomes the "konductor" and its run function is called. When it loses the lease, the run context is cancelled and the controllers shut down cleanly.
ko := konductor.NewKonductorElection(kube, event, run, onElected, konductor.Options{
Namespace: kfg.Konductor().Namespace,
LeaseDuration: kfg.Konductor().LeaseDuration,
RenewDeadline: kfg.Konductor().RenewDeadline,
RetryPeriod: kfg.Konductor().RetryPeriod,
})
ko.Start(ctx)
How it works
KonductorElection uses client-go/tools/leaderelection backed by a coordination.k8s.io/v1 Lease object. Three callbacks drive the lifecycle:
| Callback | Triggered when | Action |
|---|---|---|
OnStartedLeading |
This pod wins the lease | Calls run(ctx) with a cancellable context; records a Kubernetes event |
OnStoppedLeading |
This pod loses the lease | Cancels the run context; clears the konductor identity |
OnNewLeader |
Any pod wins | Logs the new leader identity |
ReleaseOnCancel: true ensures the Lease is released when Shutdown() is called, allowing a new pod to immediately become konductor rather than waiting for the lease to expire.
Identity
Each pod identifies itself by hostname (os.Hostname()). If the hostname call fails, a UUID is generated as a fallback. The identity appears in Konductor() after election and in the emitted Kubernetes events.
Lean election timing
Configured via pkg/konfig ENV vars:
| ENV | Default | Purpose |
|---|---|---|
LEASE_DURATION |
60s | How long a lease is valid without renewal |
RENEW_DEADLINE |
40s | How long the leader tries to renew before giving up |
RETRY_PERIOD |
10s | How often non-leaders try to acquire the lease |
For faster failover in testing, use the defaults in konfig.NewDefaultKonfig() (15s/10s/2s).
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type KonductorElection ¶
type KonductorElection struct {
// contains filtered or unexported fields
}
func NewKonductorElection ¶
func NewKonductorElection( kube *kubeclient.Kubeclient, event *event.Event, run func(context.Context), onElected func(konductor string), opts Options, ) *KonductorElection
func (*KonductorElection) Konductor ¶
func (ko *KonductorElection) Konductor() string
Konductor returns the instance that won the konductor election
func (*KonductorElection) Name ¶
func (ko *KonductorElection) Name() string
func (*KonductorElection) Shutdown ¶
func (ko *KonductorElection) Shutdown(ctx context.Context)
func (*KonductorElection) Started ¶
func (ko *KonductorElection) Started() bool
Source Files