kubernetes/kops · error

NatGateway %q has nil addresses

Error message

NatGateway %q has nil addresses

What it means

A NAT Gateway was found via the associated route table, but its NatGatewayAddresses field is nil — AWS returned no address list — leaving kOps unable to select an allocation ID for the ElasticIP task.

Source

Thrown at upup/pkg/fi/cloudup/awstasks/elastic_ip.go:91

	// Find via RouteTable -> NatGateway -> ElasticIP
	if allocationID == nil && publicIP == nil && e.AssociatedNatGatewayRouteTable != nil {
		ngw, err := findNatGatewayFromRouteTable(ctx, cloud, e.AssociatedNatGatewayRouteTable)
		if err != nil {
			return nil, fmt.Errorf("error finding AssociatedNatGatewayRouteTable: %v", err)
		}

		if ngw == nil {
			klog.V(2).Infof("AssociatedNatGatewayRouteTable not found")
		} else {
			if len(ngw.NatGatewayAddresses) == 0 {
				return nil, fmt.Errorf("NatGateway %q has no addresses", *ngw.NatGatewayId)
			}
			if len(ngw.NatGatewayAddresses) > 1 {
				return nil, fmt.Errorf("NatGateway %q has multiple addresses", *ngw.NatGatewayId)
			}
			allocationID = ngw.NatGatewayAddresses[0].AllocationId
			if allocationID == nil {
				return nil, fmt.Errorf("NatGateway %q has nil addresses", *ngw.NatGatewayId)
			} else {
				klog.V(2).Infof("Found ElasticIP AllocationID %q via NatGateway", *allocationID)
			}
		}
	}

	// Find via tag on subnet
	// TODO: Deprecated, because doesn't round-trip with terraform
	if allocationID == nil && publicIP == nil && e.TagOnSubnet != nil && e.TagOnSubnet.ID != nil {
		var filters []ec2types.Filter
		filters = append(filters, awsup.NewEC2Filter("key", "AssociatedElasticIp"))
		filters = append(filters, awsup.NewEC2Filter("resource-id", *e.TagOnSubnet.ID))

		request := &ec2.DescribeTagsInput{
			Filters: filters,
		}

		response, err := cloud.EC2().DescribeTags(ctx, request)

View on GitHub (pinned to 4c8573c808)

Solutions

1. Re-run once the NAT Gateway fully reports its addresses
2. Recreate the NAT Gateway if it never populates addresses

When it happens

Trigger: Thrown at upup/pkg/fi/cloudup/awstasks/elastic_ip.go:91 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/b896e915788e8780. Report an issue: GitHub.