layer1: add namespace bootstrap step 11

pkg/utils/namespace_manager.go

@@ -14,6 +14,7 @@ type NamespaceManager interface {
 	Snapshot() []string
 	SnapshotRecords() []NamespaceRecord
 	Get(name string) (NamespaceRecord, bool)
+	Bootstrap(namespaces []string, source NamespaceSource, observedAt time.Time) []NamespaceRecord
 	Subscribe(subscriber NamespaceSubscriber)
 	SnapshotSubscribers() []string
 	Upsert(event NamespaceEvent) NamespaceRecord
@@ -40,6 +41,22 @@ func (m *inMemoryNamespaceManager) Subscribe(subscriber NamespaceSubscriber) {
 	m.subs[subscriber.Name()] = subscriber
 }
 
+func (m *inMemoryNamespaceManager) Bootstrap(namespaces []string, source NamespaceSource, observedAt time.Time) []NamespaceRecord {
+	records := make([]NamespaceRecord, 0, len(namespaces))
+	for _, namespace := range namespaces {
+		records = append(records, m.Upsert(NamespaceEvent{
+			Type:       NamespaceEventAdd,
+			Name:       namespace,
+			Source:     source,
+			ObservedAt: observedAt,
+		}))
+	}
+	sort.Slice(records, func(i, j int) bool {
+		return records[i].Name < records[j].Name
+	})
+	return records
+}
+
 func (m *inMemoryNamespaceManager) SnapshotSubscribers() []string {
 	m.mu.RLock()
 	defer m.mu.RUnlock()