build cache only once

management/server/types/account.go

@@ -8,6 +8,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/hashicorp/go-multierror"
@@ -88,6 +89,7 @@ type Account struct {
 	Onboarding       AccountOnboarding                `gorm:"foreignKey:AccountID;references:id;constraint:OnDelete:CASCADE"`
 
 	NetworkMapCache *NetworkMapBuilder `gorm:"-"`
+	nmapInitOnce    sync.Once
 }
 
 // this class is used by gorm only

management/server/types/networkmap.go

@@ -846,10 +846,9 @@ func peerIsNameserver(peer *nbpeer.Peer, nsGroup *nbdns.NameServerGroup) bool {
 }
 
 func (a *Account) initNetworkMapBuilder(validatedPeers map[string]struct{}) {
-	if a.NetworkMapCache != nil {
-		return
-	}
-	a.NetworkMapCache = NewNetworkMapBuilder(a, validatedPeers)
+	a.nmapInitOnce.Do(func() {
+		a.NetworkMapCache = NewNetworkMapBuilder(a, validatedPeers)
+	})
 }
 
 func (a *Account) InitNetworkMapBuilderIfNeeded(validatedPeers map[string]struct{}) {