feat(tenant): add dedicated tenantowner crd (#1764)

Signed-off-by: Oliver Bähler <oliverbaehler@hotmail.com>

pkg/api/misc/selectors.go

@@ -0,0 +1,143 @@
+// Copyright 2020-2025 Project Capsule Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package misc
+
+import (
+	"context"
+	"fmt"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/meta"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+// Selector for resources and their labels or selecting origin namespaces
+// +kubebuilder:object:generate=true
+type NamespaceSelector struct {
+	// Select Items based on their labels. If the namespaceSelector is also set, the selector is applied
+	// to items within the selected namespaces. Otherwise for all the items.
+	*metav1.LabelSelector `json:",inline"`
+}
+
+// GetMatchingNamespaces retrieves the list of namespaces that match the NamespaceSelector.
+func (s *NamespaceSelector) GetMatchingNamespaces(ctx context.Context, client client.Client) ([]corev1.Namespace, error) {
+	if s.LabelSelector == nil {
+		return nil, nil // No namespace selector means all namespaces
+	}
+
+	nsSelector, err := metav1.LabelSelectorAsSelector(s.LabelSelector)
+	if err != nil {
+		return nil, fmt.Errorf("invalid namespace selector: %w", err)
+	}
+
+	namespaceList := &corev1.NamespaceList{}
+	if err := client.List(ctx, namespaceList); err != nil {
+		return nil, fmt.Errorf("failed to list namespaces: %w", err)
+	}
+
+	var matchingNamespaces []corev1.Namespace
+
+	for _, ns := range namespaceList.Items {
+		if nsSelector.Matches(labels.Set(ns.Labels)) {
+			matchingNamespaces = append(matchingNamespaces, ns)
+		}
+	}
+
+	return matchingNamespaces, nil
+}
+
+// ListBySelectors lists objects of type T (using list L), then returns all items that
+// match ANY of the provided LabelSelectors. The result is unique by namespace/name.
+func ListBySelectors[T client.Object](
+	ctx context.Context,
+	c client.Client,
+	list client.ObjectList,
+	selectors []*metav1.LabelSelector,
+) ([]T, error) {
+	if len(selectors) == 0 {
+		return nil, nil
+	}
+
+	if list == nil {
+		return nil, fmt.Errorf("list must not be nil")
+	}
+
+	// Preallocate with upper bound (len(selectors)); nil selectors will just not be used.
+	selList := make([]labels.Selector, 0, len(selectors))
+
+	for _, ls := range selectors {
+		if ls == nil {
+			continue
+		}
+
+		sel, err := metav1.LabelSelectorAsSelector(ls)
+		if err != nil {
+			return nil, fmt.Errorf("invalid label selector %v: %w", ls, err)
+		}
+
+		selList = append(selList, sel)
+	}
+
+	if len(selList) == 0 {
+		return nil, nil
+	}
+
+	// List all objects once
+	if err := c.List(ctx, list); err != nil {
+		return nil, fmt.Errorf("listing objects: %w", err)
+	}
+
+	rawItems, err := meta.ExtractList(list)
+	if err != nil {
+		return nil, fmt.Errorf("extracting list items: %w", err)
+	}
+
+	// Deduplicate by namespace/name
+	seen := make(map[client.ObjectKey]struct{}, len(rawItems))
+
+	// Upper bound: at most len(rawItems) will match; good enough for prealloc.
+	result := make([]T, 0, len(rawItems))
+
+	for _, obj := range rawItems {
+		typed, ok := obj.(T)
+		if !ok {
+			continue
+		}
+
+		lbls := typed.GetLabels()
+		if len(lbls) == 0 {
+			continue
+		}
+
+		set := labels.Set(lbls)
+
+		// Match against ANY selector
+		matched := false
+
+		for _, sel := range selList {
+			if sel.Matches(set) {
+				matched = true
+
+				break
+			}
+		}
+
+		if !matched {
+			continue
+		}
+
+		key := client.ObjectKeyFromObject(typed)
+		if _, exists := seen[key]; exists {
+			continue
+		}
+
+		seen[key] = struct{}{}
+
+		result = append(result, typed)
+	}
+
+	return result, nil
+}

pkg/api/misc/zz_generated.deepcopy.go

@@ -0,0 +1,32 @@
+//go:build !ignore_autogenerated
+
+// Copyright 2020-2023 Project Capsule Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+// Code generated by controller-gen. DO NOT EDIT.
+
+package misc
+
+import (
+	"k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *NamespaceSelector) DeepCopyInto(out *NamespaceSelector) {
+	*out = *in
+	if in.LabelSelector != nil {
+		in, out := &in.LabelSelector, &out.LabelSelector
+		*out = new(v1.LabelSelector)
+		(*in).DeepCopyInto(*out)
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new NamespaceSelector.
+func (in *NamespaceSelector) DeepCopy() *NamespaceSelector {
+	if in == nil {
+		return nil
+	}
+	out := new(NamespaceSelector)
+	in.DeepCopyInto(out)
+	return out
+}