event.md

Event

The Event API defines what information a report of an event issued by a controller should contain.

Specification

Spec:

type Event struct {
	// The object that this event is about.
	// +required
	InvolvedObject corev1.ObjectReference `json:"involvedObject"`

	// Severity type of this event (info, error)
	// +required
	Severity string `json:"severity"`

	// The time at which this event was recorded.
	// +required
	Timestamp metav1.Time `json:"timestamp"`

	// A human-readable description of this event.
	// Maximum length 39,000 characters
	// +required
	Message string `json:"message"`

	// A machine understandable string that gives the reason
	// for the transition into the object's current status.
	// +required
	Reason string `json:"reason"`

	// Metadata of this event, e.g. apply change set.
	// +optional
	Metadata map[string]string `json:"metadata,omitempty"`

	// Name of the controller that emitted this event, e.g. `source-controller`.
	// +required
	ReportingController string `json:"reportingController"`

	// ID of the controller instance, e.g. `source-controller-xyzf`.
	// +optional
	ReportingInstance string `json:"reportingInstance,omitempty"`
}

Event severity:

const (
	EventSeverityInfo string = "info"
	EventSeverityError string = "error"
)

Controller implementations can use the fluxcd/pkg/runtime/events package to push events to notification-controller API.

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.Name, InvolvedObject.Namespace, InvolvedObject.Kind, Message, and Metadata.revision. The interval of the rate limit is set by default to 5m but can be configured with the --rate-limit-interval option.

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:

rate(gotk_event_http_request_duration_seconds_count{code="429"}[30s])