[management] Expire unvalidated custom domain registrations (#7497)

Prevent unvalidated registrations from reserving domain names indefinitely.

Give pending registrations a 48-hour validation window and clean up expired entries at startup and every 60 minutes. Emit CustomDomainValidationExpired for each deletion and preserve registrations referenced by services.

Reject validation after expiry and prevent concurrent validation from recreating deleted registrations. Normalize domain names with the shared parser before registration.

Migrate existing pending registrations to receive a fresh 48-hour validation window.

management/internals/modules/reverseproxy/domain/manager/manager.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net"
 	"strings"
+	"time"
 
 	log "github.com/sirupsen/logrus"
 
@@ -18,6 +19,7 @@ import (
 	"github.com/netbirdio/netbird/management/server/permissions/operations"
 	nbstore "github.com/netbirdio/netbird/management/server/store"
 	"github.com/netbirdio/netbird/management/server/types"
+	nbdomain "github.com/netbirdio/netbird/shared/management/domain"
 	"github.com/netbirdio/netbird/shared/management/status"
 )
 
@@ -32,6 +34,8 @@ type store interface {
 	CreateCustomDomain(ctx context.Context, accountID string, domainName string, targetCluster string, validated bool) (*domain.Domain, error)
 	UpdateCustomDomain(ctx context.Context, accountID string, d *domain.Domain) (*domain.Domain, error)
 	DeleteCustomDomain(ctx context.Context, accountID string, domainID string) error
+	GetExpiredCustomDomains(ctx context.Context, now time.Time, afterID domain.ID, limit int) ([]*domain.Domain, error)
+	DeleteExpiredCustomDomain(ctx context.Context, d *domain.Domain, now time.Time) (bool, error)
 }
 
 type proxyManager interface {
@@ -106,12 +110,13 @@ func (m Manager) GetDomains(ctx context.Context, accountID, userID string) ([]*d
 	// Add custom domains.
 	for _, d := range domains {
 		cd := &domain.Domain{
-			ID:            d.ID,
-			Domain:        d.Domain,
-			AccountID:     accountID,
-			TargetCluster: d.TargetCluster,
-			Type:          domain.TypeCustom,
-			Validated:     d.Validated,
+			ID:                  d.ID,
+			Domain:              d.Domain,
+			AccountID:           accountID,
+			TargetCluster:       d.TargetCluster,
+			Type:                domain.TypeCustom,
+			Validated:           d.Validated,
+			ValidationExpiresAt: d.ValidationExpiresAt,
 		}
 		if d.TargetCluster != "" {
 			cd.SupportsCustomPorts = m.proxyManager.ClusterSupportsCustomPorts(ctx, d.TargetCluster)
@@ -126,6 +131,7 @@ func (m Manager) GetDomains(ctx context.Context, accountID, userID string) ([]*d
 	return ret, nil
 }
 
+// CreateDomain registers a normalized custom domain and attempts DNS validation.
 func (m Manager) CreateDomain(ctx context.Context, accountID, userID, domainName, targetCluster string) (*domain.Domain, error) {
 	ok, ctx, err := m.permissionsManager.ValidateUserPermissions(ctx, accountID, userID, modules.Services, operations.Create)
 	if err != nil {
@@ -135,6 +141,15 @@ func (m Manager) CreateDomain(ctx context.Context, accountID, userID, domainName
 		return nil, status.NewPermissionDeniedError()
 	}
 
+	parsed, err := nbdomain.FromString(strings.TrimSuffix(domainName, "."))
+	if err != nil {
+		return nil, status.Errorf(status.InvalidArgument, "invalid domain: %v", err)
+	}
+	domainName = parsed.PunycodeString()
+	if !nbdomain.IsValidDomainNoWildcard(domainName) {
+		return nil, status.Errorf(status.InvalidArgument, "invalid domain format")
+	}
+
 	// Verify the target cluster is in the available clusters for this account
 	allowList, err := m.getClusterAllowList(ctx, accountID)
 	if err != nil {
@@ -243,6 +258,14 @@ func (m Manager) ValidateDomain(ctx context.Context, accountID, userID, domainID
 		}).WithError(err).Error("get custom domain from store")
 		return
 	}
+	if d.Validated {
+		return
+	}
+	if d.ValidationExpiresAt == nil || !time.Now().Before(*d.ValidationExpiresAt) {
+		log.WithFields(log.Fields{"accountID": accountID, "domainID": domainID}).
+			Debug("custom domain validation window has expired")
+		return
+	}
 
 	// Validate only against the domain's target cluster
 	targetCluster := d.TargetCluster
@@ -263,20 +286,21 @@ func (m Manager) ValidateDomain(ctx context.Context, accountID, userID, domainID
 	}).Info("validating domain against target cluster")
 
 	if m.validator.IsValid(context.Background(), d.Domain, []string{targetCluster}) {
-		log.WithFields(log.Fields{
-			"accountID": accountID,
-			"domainID":  domainID,
-			"domain":    d.Domain,
-		}).Info("domain validated successfully")
 		d.Validated = true
 		if _, err := m.store.UpdateCustomDomain(context.Background(), accountID, d); err != nil {
-			log.WithFields(log.Fields{
+			entry := log.WithFields(log.Fields{
 				"accountID": accountID,
 				"domainID":  domainID,
-				"domain":    d.Domain,
-			}).WithError(err).Error("update custom domain in store")
+			}).WithError(err)
+			if sErr, ok := status.FromError(err); ok && sErr.Type() == status.PreconditionFailed {
+				entry.Debug("custom domain registration is no longer pending validation")
+				return
+			}
+			entry.Error("update custom domain in store")
 			return
 		}
+		log.WithFields(log.Fields{"accountID": accountID, "domainID": domainID}).
+			Info("custom domain validated successfully")
 
 		m.accountManager.StoreEvent(context.Background(), userID, domainID, accountID, activity.DomainValidated, d.EventMeta())
 	} else {