kubernetes/kops · error

SpotInstanceGroup %q cannot be in subnets of different Type

Error message

SpotInstanceGroup %q cannot be in subnets of different Type

What it means

Raised by buildPublicIPOpts when the SpotInstanceGroup's subnets include more than one distinct kops.SubnetType (e.g. mixing Public and Private). Since the builder derives a single public-IP policy from the subnet type, mixed types are ambiguous and rejected.

Source

Thrown at pkg/model/awsmodel/spotinst.go:741

	return out, nil
}

func (b *SpotInstanceGroupModelBuilder) buildPublicIPOpts(ig *kops.InstanceGroup) (*bool, error) {
	subnetMap := make(map[string]*kops.ClusterSubnetSpec)
	for i := range b.Cluster.Spec.Networking.Subnets {
		subnet := &b.Cluster.Spec.Networking.Subnets[i]
		subnetMap[subnet.Name] = subnet
	}

	var subnetType kops.SubnetType
	for _, subnetName := range ig.Spec.Subnets {
		subnet := subnetMap[subnetName]
		if subnet == nil {
			return nil, fmt.Errorf("SpotInstanceGroup %q uses subnet %q that does not exist", ig.ObjectMeta.Name, subnetName)
		}
		if subnetType != "" && subnetType != subnet.Type {
			return nil, fmt.Errorf("SpotInstanceGroup %q cannot be in subnets of different Type", ig.ObjectMeta.Name)
		}
		subnetType = subnet.Type
	}

	var associatePublicIP bool
	switch subnetType {
	case kops.SubnetTypePublic, kops.SubnetTypeUtility:
		associatePublicIP = true
		if ig.Spec.AssociatePublicIP != nil {
			associatePublicIP = *ig.Spec.AssociatePublicIP
		}
	case kops.SubnetTypeDualStack, kops.SubnetTypePrivate:
		associatePublicIP = false
		if ig.Spec.AssociatePublicIP != nil {
			if *ig.Spec.AssociatePublicIP {
				klog.Warningf("Ignoring AssociatePublicIPAddress=true for private SpotInstanceGroup %q", ig.ObjectMeta.Name)
			}
		}

View on GitHub (pinned to 4c8573c808)

Solutions

1. Ensure all subnets in spec.subnets have the same type in the cluster spec
2. Split the instance group into one per subnet type
3. Run kops get cluster to inspect each subnet's type
4. Re-run kops update --yes

Example fix

// before
spec:
  subnets: [public-a, private-b]
// after (split into two IGs)
spec:
  subnets: [private-a, private-b]

types := map[kops.SubnetType]bool{}
for _, igSubnet := range ig.Spec.Subnets {
  for _, s := range cluster.Spec.Subnets {
    if s.Name == igSubnet { types[s.Type] = true }
  }
}
if len(types) > 1 {
  return fmt.Errorf("IG %s spans subnets of different types", ig.Name)
}

When it happens

Trigger: kops create/update where spec.subnets on a Spotinst IG references both public and private subnets (or DualStack/Private variants of different types).

Common situations: Splitting a node group across a public and private subnet during migration, or copy-pasting subnet lists from a cluster with a different topology.

Related errors

• could not determine any subnets for SpotInstanceGroup %q; su
• SpotInstanceGroup %q uses subnet %q that does not exist
• error building public ip options: %v
• error building subnets: %v
• unknown subnet type %q

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/c7110158b779ddef. Report an issue: GitHub.