Add annotation to trigger directed resource reconciliation. (#53)

api/v2/types_annotations.go

@@ -0,0 +1,183 @@
+package v2
+
+import (
+	"context"
+	"strconv"
+
+	"github.com/google/go-cmp/cmp"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/event"
+	"sigs.k8s.io/controller-runtime/pkg/predicate"
+)
+
+const (
+	// ReconcileAnnotation can be used to trigger a reconciliation of a resource managed by a controller.
+	// The value of the annotation does not matter, the controller will cleanup the annotation automatically and trigger a reconciliation of the resource.
+	ReconcileAnnotation = "firewall.metal-stack.io/reconcile"
+	// MaintenanceAnnotation can be used to trigger a maintenance reconciliation for which a controller might have special behavior.
+	// The value of the annotation does not matter, the controller will cleanup the annotation automatically.
+	MaintenanceAnnotation = "firewall.metal-stack.io/maintain"
+	// RollSetAnnotation can be used to trigger a rolling update of a firewall deployment.
+	// The value of the annotation needs to be true otherwise the controller will ignore it.
+	RollSetAnnotation = "firewall.metal-stack.io/roll-set"
+	// RevisionAnnotation stores the revision number of a resource.
+	RevisionAnnotation = "firewall.metal-stack.io/revision"
+
+	// FirewallNoControllerConnectionAnnotation can be used as an annotation to the firewall resource in order
+	// to indicate that the firewall-controller does not connect to the firewall monitor. this way, the replica
+	// set will become healthy without a controller connection.
+	//
+	// this can be useful to silence a problem temporarily and was used in the past for migration of firewall-controller v1.
+	FirewallNoControllerConnectionAnnotation = "firewall.metal-stack.io/no-controller-connection"
+	// FirewallControllerManagedByAnnotation is used as tag for creating a firewall to indicate who is managing the firewall.
+	FirewallControllerManagedByAnnotation = "firewall.metal-stack.io/managed-by"
+	// FirewallWeightAnnotation is considered when deciding which firewall is thrown away on scale down.
+	// Value must be parsable as an integer. Firewalls with higher weight are kept longer.
+	// Defaults to 0 if no annotation is present. Negative values are allowed.
+	FirewallWeightAnnotation = "firewall.metal-stack.io/weight"
+
+	// FirewallControllerSetAnnotation is a tag added to the firewall entity indicating to which set a firewall belongs to.
+	FirewallControllerSetAnnotation = "firewall.metal.stack.io/set"
+)
+
+// IsAnnotationPresent returns true if the given object has an annotation with a given
+// key, the value of this annotation does not matter.
+func IsAnnotationPresent(o client.Object, key string) bool {
+	_, ok := o.GetAnnotations()[key]
+	return ok
+}
+
+// IsAnnotationTrue returns true if the given object has an annotation with a given
+// key and the value of this annotation is a true boolean.
+func IsAnnotationTrue(o client.Object, key string) bool {
+	enabled, err := strconv.ParseBool(o.GetAnnotations()[key])
+	return err == nil && enabled
+}
+
+// IsAnnotationFalse returns true if the given object has an annotation with a given
+// key and the value of this annotation is a false boolean.
+func IsAnnotationFalse(o client.Object, key string) bool {
+	enabled, err := strconv.ParseBool(o.GetAnnotations()[key])
+	return err == nil && !enabled
+}
+
+// AddAnnotation adds an annotation by a given key to an object if not present by updating it with the given client.
+func AddAnnotation(ctx context.Context, c client.Client, o client.Object, key, value string) error {
+	annotations := o.GetAnnotations()
+
+	if annotations == nil {
+		annotations = map[string]string{}
+	}
+
+	if existingValue, ok := annotations[key]; ok && existingValue == value {
+		return nil
+	}
+
+	annotations[key] = value
+
+	o.SetAnnotations(annotations)
+
+	err := c.Update(ctx, o)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// RemoveAnnotation removes an annotation by a given key from an object if present by updating it with the given client.
+func RemoveAnnotation(ctx context.Context, c client.Client, o client.Object, key string) error {
+	annotations := o.GetAnnotations()
+
+	if annotations == nil {
+		return nil
+	}
+
+	_, ok := annotations[key]
+	if !ok {
+		return nil
+	}
+
+	delete(annotations, key)
+
+	o.SetAnnotations(annotations)
+
+	err := c.Update(ctx, o)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// AnnotationAddedPredicate returns a predicate when the given annotation key was added.
+func AnnotationAddedPredicate(annotation string) predicate.Funcs {
+	return predicate.Funcs{
+		CreateFunc: func(ce event.CreateEvent) bool {
+			return false
+		},
+		UpdateFunc: func(update event.UpdateEvent) bool {
+			return annotationWasAdded(update, annotation)
+		},
+		DeleteFunc: func(de event.DeleteEvent) bool {
+			return false
+		},
+	}
+}
+
+// AnnotationRemovedPredicate returns a predicate when the given annotation key was removed.
+func AnnotationRemovedPredicate(annotation string) predicate.Funcs {
+	return predicate.Funcs{
+		CreateFunc: func(ce event.CreateEvent) bool {
+			return false
+		},
+		UpdateFunc: func(update event.UpdateEvent) bool {
+			return annotationWasRemoved(update, annotation)
+		},
+		DeleteFunc: func(de event.DeleteEvent) bool {
+			return false
+		},
+	}
+}
+
+func annotationWasRemoved(update event.UpdateEvent, annotation string) bool {
+	if cmp.Equal(update.ObjectOld.GetAnnotations(), update.ObjectNew.GetAnnotations()) {
+		return false
+	}
+
+	var (
+		_, o = update.ObjectOld.GetAnnotations()[annotation]
+		_, n = update.ObjectNew.GetAnnotations()[annotation]
+	)
+
+	if n {
+		return false
+	}
+
+	if !o {
+		return false
+	}
+
+	return o && !n
+}
+
+func annotationWasAdded(update event.UpdateEvent, annotation string) bool {
+	if cmp.Equal(update.ObjectOld.GetAnnotations(), update.ObjectNew.GetAnnotations()) {
+		return false
+	}
+
+	var (
+		_, o = update.ObjectOld.GetAnnotations()[annotation]
+		_, n = update.ObjectNew.GetAnnotations()[annotation]
+	)
+
+	if o {
+		return false
+	}
+
+	if !n {
+		return false
+	}
+
+	return !o && n
+}