kubernetes/kops · error

linode VPC requires at least one subnet

Error message

linode VPC requires at least one subnet

What it means

The Linode NetworkModelBuilder.Build() validates the cluster's networking configuration before generating VPC/subnet tasks. Linode clusters require at least one subnet defined in cluster.spec.networking.subnets; if the list is empty, the build aborts with this static error.

Source

Thrown at pkg/model/linodemodel/network.go:37

import (
	"fmt"

	"k8s.io/kops/upup/pkg/fi"
	"k8s.io/kops/upup/pkg/fi/cloudup/linode"
	"k8s.io/kops/upup/pkg/fi/cloudup/linodetasks"
)

// NetworkModelBuilder configures the Akamai (Linode) VPC for the cluster.
type NetworkModelBuilder struct {
	*LinodeModelContext
	Lifecycle fi.Lifecycle
}

var _ fi.CloudupModelBuilder = &NetworkModelBuilder{}

func (b *NetworkModelBuilder) Build(c *fi.CloudupModelBuilderContext) error {
	if len(b.Cluster.Spec.Networking.Subnets) == 0 {
		return fmt.Errorf("linode VPC requires at least one subnet")
	}

	seenSubnetNames := map[string]string{}
	region := ""
	for i, subnet := range b.Cluster.Spec.Networking.Subnets {
		subnetName := subnet.Name
		if subnetName == "" {
			subnetName = fmt.Sprintf("subnet %d", i)
		}

		if subnet.Name == "" {
			return fmt.Errorf("linode subnet %q requires a name", subnetName)
		}
		if subnet.Region == "" {
			return fmt.Errorf("linode subnet %q requires a region", subnetName)
		}
		if subnet.CIDR == "" {
			return fmt.Errorf("linode subnet %q requires a CIDR", subnetName)

View on GitHub (pinned to 4c8573c808)

Solutions

1. Add at least one subnet to cluster.spec.networking.subnets with name, region, and CIDR set.
2. Re-run kops update cluster --yes after fixing the manifest.
3. If using a cluster template, verify the templating filled in the subnets section.

Example fix

// before
networking:
  subnets: []
// after
networking:
  subnets:
  - name: us-east-1a
    region: us-east
    cidr: 10.0.0.0/24

if len(cluster.Spec.Networking.Subnets) == 0 {
    return errors.New("cluster.spec.networking.subnets must define at least one subnet for Linode")
}

When it happens

Trigger: Creating or updating a Linode cluster whose manifest omits spec.networking.subnets entirely, or after a spec edit/tooling pass stripped the subnets array.

Common situations: Hand-written cluster manifests missing the subnets section; kops toolbox template rendering producing empty subnets; migrating a cluster spec from a provider where subnets are optional.

Related errors

• linode subnet %q requires a name
• linode subnet %q requires a region
• linode subnet %q requires a CIDR
• Subnet.VPC is required
• Subnet.VPC.ID is required

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/c1ff180d64106ffc. Report an issue: GitHub.