kubernetes/kops · error

error modifying hostname type: %w

Error message

error modifying hostname type: %w

What it means

ModifySubnetAttribute failed while changing PrivateDnsHostnameTypeOnLaunch (IP-name vs resource-based naming) on the subnet; the wrapped error is the AWS API response.

Source

Thrown at upup/pkg/fi/cloudup/awstasks/subnet.go:323

		}
		_, err := t.Cloud.EC2().ModifySubnetAttribute(ctx, request)
		if err != nil {
			return fmt.Errorf("error modifying AssignIPv6AddressOnCreation: %w", err)
		}
	}

	if changes.ResourceBasedNaming != nil {
		hostnameType := ec2types.HostnameTypeIpName
		if *changes.ResourceBasedNaming {
			hostnameType = ec2types.HostnameTypeResourceName
		}
		request := &ec2.ModifySubnetAttributeInput{
			SubnetId:                       e.ID,
			PrivateDnsHostnameTypeOnLaunch: hostnameType,
		}
		_, err := t.Cloud.EC2().ModifySubnetAttribute(ctx, request)
		if err != nil {
			return fmt.Errorf("error modifying hostname type: %w", err)
		}

		if fi.ValueOf(e.CIDR) == "" {
			request = &ec2.ModifySubnetAttributeInput{
				SubnetId:    e.ID,
				EnableDns64: &ec2types.AttributeBooleanValue{Value: aws.Bool(true)},
			}
			_, err = t.Cloud.EC2().ModifySubnetAttribute(ctx, request)
			if err != nil {
				return fmt.Errorf("error enabling DNS64: %w", err)
			}
		} else {
			request = &ec2.ModifySubnetAttributeInput{
				SubnetId:                             e.ID,
				EnableResourceNameDnsARecordOnLaunch: &ec2types.AttributeBooleanValue{Value: changes.ResourceBasedNaming},
			}
			_, err = t.Cloud.EC2().ModifySubnetAttribute(ctx, request)
			if err != nil {

View on GitHub (pinned to 4c8573c808)

Solutions

1. Check ec2:ModifySubnetAttribute permissions
2. Ensure resource-based naming is supported in the region/account before enabling it

When it happens

Trigger: Thrown at upup/pkg/fi/cloudup/awstasks/subnet.go:323 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/3ea3b4db74da3279. Report an issue: GitHub.