kubernetes/kops · error

getting control plane VMSS name for API ingress status

Error message

getting control plane VMSS name for API ingress status

What it means

After listing scale sets in the cluster resource group, kOps searches for a scale set tagged as the control plane (via TagClusterName plus control-plane/master role tags). If no scale set matches — i.e. vmssName stays empty — GetApiIngressStatus returns this error. It means the cluster resource group contains no scale set carrying the expected control plane tags.

Source

Thrown at upup/pkg/fi/cloudup/azure/azure_cloud.go:336

		}
	} else {
		// Get scale sets in cluster resource group and find masters scale set
		scaleSets, err := c.vmscaleSetsClient.List(context.TODO(), rg)
		if err != nil {
			return nil, fmt.Errorf("getting cluster control plane VMSS for API ingress status: %w", err)
		}
		var vmssName string
		for _, scaleSet := range scaleSets {
			val, ok := scaleSet.Tags[TagClusterName]
			val2, ok2 := scaleSet.Tags[TagNameRolePrefix+TagRoleControlPlane]
			val3, ok3 := scaleSet.Tags[TagNameRolePrefix+TagRoleMaster]
			if ok && *val == cluster.Name && (ok2 && *val2 == "1" || ok3 && *val3 == "1") {
				vmssName = *scaleSet.Name
				break
			}
		}
		if vmssName == "" {
			return nil, fmt.Errorf("getting control plane VMSS name for API ingress status")
		}

		// Get masters scale set network interfaces and append to api ingress status
		nis, err := c.NetworkInterface().ListScaleSetsNetworkInterfaces(context.TODO(), rg, vmssName)
		if err != nil {
			return nil, fmt.Errorf("getting control plane VMSS network interfaces for API ingress status: %w", err)
		}
		for _, ni := range nis {
			if ni.Properties == nil || ni.Properties.Primary == nil || !*ni.Properties.Primary {
				continue
			}
			for _, i := range ni.Properties.IPConfigurations {
				if i.Properties == nil || i.Properties.PrivateIPAddress == nil {
					continue
				}
				ingresses = append(ingresses, fi.ApiIngressStatus{
					IP: *i.Properties.PrivateIPAddress,
				})

View on GitHub (pinned to 4c8573c808)

Solutions

1. Inspect the control plane VMSS tags in Azure (az vmss list -g <rg> -o table) and restore the missing kops tags (kops.k8s.io/cluster-name and kops.k8s.io/role.control-plane="1").
2. Confirm you are querying the correct cluster: run kops get clusters and compare the cluster name.
3. Verify the cluster was actually created with VMSS-based control plane (kOps 1.24+ on Azure); older VM-based control planes will not be found by this path.
4. Recreate the control plane via `kops update cluster` if tags cannot be repaired.
5. Check the resource group actually corresponds to this cluster (TagClusterName matching).

Example fix

null

// Go: confirm a tagged control plane VMSS exists before calling GetApiIngressStatus
vmssClient, _ := armcompute.NewVirtualMachineScaleSetsClient(subID, cred, nil)
pager := vmssClient.NewListPager(clusterResourceGroup, nil)
found := false
for pager.More() {
    page, err := pager.NextPage(ctx)
    if err != nil { return err }
    for _, ss := range page.Value {
        if ss.Tags["kops.k8s.io/cluster-name"] != nil &&
            (*ss.Tags["kops.k8s.io/cluster-name"] == clusterName) {
            found = true
        }
    }
}
if !found { return fmt.Errorf("no control-plane VMSS tagged for cluster %s", clusterName) }

func hasTag(tags map[string]*string, key, want string) bool {
    v, ok := tags[key]
    return ok && v != nil && *v == want
}

status, err := cloud.GetApiIngressStatus(cluster)
if err != nil && strings.Contains(err.Error(), "getting control plane VMSS name") {
    log.Printf("control plane VMSS not found by tags; check kops.k8s.io/cluster-name and role tags: %v", err)
    return err
}

When it happens

Trigger: GetApiIngressStatus runs, scale set listing succeeds, but none of the returned VMSS have a TagClusterName tag equal to the cluster name AND a control-plane/master role tag (kops.k8s.io/role.control-plane or role.master) equal to "1".

Common situations: Tags on the control plane VMSS were manually removed or edited in the Azure portal; cluster renamed so the TagClusterName value no longer matches; using an older kOps cluster whose control plane used VMs instead of VMSS while the new code path expects a scale set; querying the wrong resource group.

Related errors

• expected exactly one subnet for InstanceGroup %q; subnets wa
• unexpected subnet type: for InstanceGroup %q; type was %s
• instance group must have the same min and max size in Azure,
• malformed format of image urn: %s
• creating VMSS VMs client: %w

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/db5a33676655448c. Report an issue: GitHub.