kubernetes/kops · error

Subnet ID is required for subnet name=%v

Error message

Subnet ID is required for subnet name=%v

What it means

CheckChanges requires every expected NLB SubnetMapping to carry a concrete subnet ID (shared/managed subnets must already be resolved); a mapping still had only a Name, so the diff cannot be validated.

Source

Thrown at upup/pkg/fi/cloudup/awstasks/network_load_balancer.go:441

		}

		if e.AccessLog != nil {
			if e.AccessLog.Enabled == nil {
				return fi.RequiredField("Accesslog.Enabled")
			}
			if *e.AccessLog.Enabled {
				if e.AccessLog.S3BucketName == nil {
					return fi.RequiredField("Accesslog.S3Bucket")
				}
			}
		}
	} else {
		if len(changes.SubnetMappings) > 0 {
			expectedSubnets := make(map[string]*string)
			for _, s := range e.SubnetMappings {
				subnetID := fi.ValueOf(s.Subnet.ID)
				if subnetID == "" {
					return fmt.Errorf("Subnet ID is required for subnet name=%v", fi.ValueOf(s.Subnet.Name))
				}
				if s.AllocationID != nil {
					expectedSubnets[subnetID] = s.AllocationID
				} else if s.PrivateIPv4Address != nil {
					expectedSubnets[subnetID] = s.PrivateIPv4Address
				} else {
					expectedSubnets[subnetID] = nil
				}
			}

			for _, s := range a.SubnetMappings {
				subnetID := fi.ValueOf(s.Subnet.ID)
				if subnetID == "" {
					return fmt.Errorf("Subnet ID is required for subnet name=%v", fi.ValueOf(s.Subnet.Name))
				}

				eIP, ok := expectedSubnets[subnetID]
				if !ok {

View on GitHub (pinned to 4c8573c808)

Solutions

1. Ensure the referenced subnets exist (or are tagged for discovery) before running the apply; run `kops update` first
2. Give shared subnets explicit ids in the spec so they resolve deterministically

When it happens

Trigger: Thrown at upup/pkg/fi/cloudup/awstasks/network_load_balancer.go:441 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/69f9455872e5ba51. Report an issue: GitHub.