README
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pkg/controller/configchange
ConfigMap change handler.
Overview
Watches specific ConfigMap and publishes change events.
Quick Start
handler := configchange.NewConfigChangeHandler(bus, k8sClient, configMapName, namespace, logger)
go handler.Start(ctx)
Events
- Publishes: ConfigResourceChangedEvent
License
See main repository for license information.
Documentation
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Index ¶
Constants ¶
const ( // ComponentName is the unique identifier for this component. ComponentName = "configchange-handler" // EventBufferSize is the size of the event subscription buffer. // Size 50: Moderate-volume component handling config and validation events. EventBufferSize = 50 // DefaultReinitDebounceInterval is the default time to wait after the last config // change before signaling controller reinitialization. This allows rapid CRD updates // to be coalesced, ensuring templates are fully rendered before reinitialization starts. DefaultReinitDebounceInterval = 500 * time.Millisecond )
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type CRDWatcher ¶
type CRDWatcher struct {
// contains filtered or unexported fields
}
CRDWatcher watches HAProxyTemplateConfig CRD changes and publishes ConfigResourceChangedEvent.
This component bridges the Kubernetes informer pattern with the controller's event-driven architecture. It watches a single HAProxyTemplateConfig CRD instance and publishes events whenever the resource is added, updated, or deleted.
Architecture: - Uses generated informer from pkg/generated/informers - Publishes ConfigResourceChangedEvent (same as ConfigMap watcher for compatibility) - Converts typed CRD to unstructured format for consistent handling downstream.
func NewCRDWatcher ¶
func NewCRDWatcher( client versioned.Interface, eventBus *busevents.EventBus, logger *slog.Logger, namespace string, name string, ) *CRDWatcher
NewCRDWatcher creates a new CRDWatcher.
Parameters:
- client: Kubernetes client for HAProxyTemplateConfig CRD
- eventBus: EventBus to publish ConfigResourceChangedEvent
- logger: Structured logger for diagnostics
- namespace: Namespace containing the HAProxyTemplateConfig resource
- name: Name of the HAProxyTemplateConfig resource to watch
Returns:
- *CRDWatcher ready to start
func (*CRDWatcher) Start ¶
func (w *CRDWatcher) Start(ctx context.Context) error
Start begins watching the HAProxyTemplateConfig CRD.
This method blocks until Stop() is called or the context is canceled. It should typically be run in a goroutine.
Example:
watcher := NewCRDWatcher(client, bus, logger, "default", "haproxy-config") go watcher.Start(ctx)
type ConfigChangeHandler ¶
type ConfigChangeHandler struct {
// contains filtered or unexported fields
}
ConfigChangeHandler coordinates configuration validation and detects config changes.
This component has two main responsibilities:
Validation Coordination: Subscribes to ConfigParsedEvent, sends ConfigValidationRequest, collects responses from validators using scatter-gather pattern, and publishes ConfigValidatedEvent or ConfigInvalidEvent.
Change Detection: Subscribes to ConfigValidatedEvent and signals the controller to reinitialize via the configChangeCh channel with debouncing to coalesce rapid changes.
Debouncing behavior: When multiple CRD config changes arrive in rapid succession, the handler debounces the reinitialization signal. This ensures all pending renders complete before reinitialization starts, preventing the race condition where reinitialization cancels in-progress renders.
Architecture: This component bridges the gap between configuration parsing and validation, and between validation and controller reinitialization. It uses the scatter-gather pattern from the event bus for coordinating validation across multiple validators.
func NewConfigChangeHandler ¶
func NewConfigChangeHandler( eventBus *busevents.EventBus, logger *slog.Logger, configChangeCh chan<- *coreconfig.Config, validators []string, debounceInterval time.Duration, ) *ConfigChangeHandler
NewConfigChangeHandler creates a new ConfigChangeHandler.
Parameters:
- eventBus: The EventBus to subscribe to and publish on
- logger: Structured logger for diagnostics
- configChangeCh: Channel to signal controller reinitialization with validated config
- validators: List of expected validator names (e.g., ["basic", "template", "jsonpath"])
- debounceInterval: Time to wait after last config change before triggering reinitialization. Use 0 for default (500ms).
Returns:
- *ConfigChangeHandler ready to start
func (*ConfigChangeHandler) SetInitialConfigVersion ¶
func (h *ConfigChangeHandler) SetInitialConfigVersion(version string)
SetInitialConfigVersion sets the initial config version to prevent reinitialization on bootstrap ConfigValidatedEvent.
This must be called after fetching the initial config but before CRDWatcher starts. When CRDWatcher's informer triggers onAdd for the existing CRD, it publishes a ConfigValidatedEvent with the same version. Without this tracking, that event would trigger reinitialization, creating an infinite loop.
Parameters:
- version: The resourceVersion from the initial CRD fetch
func (*ConfigChangeHandler) Start ¶
func (h *ConfigChangeHandler) Start(ctx context.Context) error
Start begins processing events from the EventBus.
This method blocks until Stop() is called or the context is canceled. The component is already subscribed to the EventBus (subscription happens in constructor). Returns nil on graceful shutdown.
Example:
go handler.Start(ctx)
func (*ConfigChangeHandler) Stop ¶
func (h *ConfigChangeHandler) Stop()
Stop gracefully stops the component.
Source Files