The GitOps Toolkit Custom Resource Definitions documentation.

The Event API defines the structure of the events issued by Flux controllers.

Flux controllers use the fluxcd/pkg/runtime/events package to push events to the notification-controller API.


The following is an example of an event sent by kustomize-controller to report a reconciliation error.

  "involvedObject": {
    "apiVersion": "",
    "kind": "Kustomization",
    "name": "webapp",
    "namespace": "apps",
    "uid": "7d0cdc51-ddcf-4743-b223-83ca5c699632"
  "metadata": {
    "": "main/731f7eaddfb6af01cb2173e18f0f75b0ba780ef1"
  "reason": "ValidationFailed",
  "message":"service/apps/webapp validation error: spec.type: Unsupported value: Ingress",

In the above example:

  • An event is issued by kustomize-controller for a specific object, indicated in the involvedObject field.
  • The notification-controller receives the event and finds the alerts that match the involvedObject and severity values.
  • For all matching alerts, the controller posts the message and the source revision extracted from metadata to the alert provider API.

Event structure

The Go type that defines the event structure can be found in the fluxcd/pkg/apis/event/v1beta1 package.

Rate limiting

Events received by notification-controller are subject to rate limiting to reduce the amount of duplicate alerts sent to external systems like Slack, Sentry, etc.

Events are rate limited based on, involvedObject.namespace, involvedObject.kind, message, and metadata. The interval of the rate limit is set by default to 5m but can be configured with the --rate-limit-interval controller flag.

The event server exposes HTTP request metrics to track the amount of rate limited events. The following promql will get the rate at which requests are rate limited: