What causes "found multiple gcp regions for cluster" in kubernetes/kops?

Make all subnets belong to the same GCP region

found multiple gcp regions for cluster

Error message

found multiple gcp regions for cluster

What it means

applyGCPCluster derives a single GCP region from the cluster subnets and rejects clusters whose subnets span more than one region, since a GCPCluster object is region-scoped. When two or more subnets have different Region values, reconciliation fails with this error.

Source

Thrown at pkg/controllers/clusterapi/cluster_controller.go:124

	}
	return nil
}

func (s *clusterScope) applyGCPCluster(ctx context.Context, kube client.Client) error {
	// This is because of network tags in cloud-provider-gcp
	// TODO: cloud-provider-gcp should not assume cluster name is a valid prefix
	name := gce.SafeClusterName(s.Cluster.GetName())

	gcpProject := s.Cluster.Spec.Project
	if gcpProject == "" {
		return fmt.Errorf("unable to determine gcp project for cluster")
	}
	gcpRegion := ""
	for _, subnet := range s.Cluster.Spec.Subnets {
		if gcpRegion == "" {
			gcpRegion = subnet.Region
		} else if gcpRegion != subnet.Region {
			return fmt.Errorf("found multiple gcp regions for cluster")
		}
	}
	if gcpRegion == "" {
		return fmt.Errorf("unable to determine gcp region for cluster")
	}

	// TODO: Sync with LinkToNetwork
	gcpNetworkName := s.Cluster.Spec.NetworkID
	if gcpNetworkName == "" {
		gcpNetworkName = gce.SafeTruncatedClusterName(s.Cluster.ObjectMeta.Name, 63)
	}
	if gcpNetworkName == "" {
		return fmt.Errorf("unable to determine gcp network for cluster")
	}

	obj := map[string]any{
		"apiVersion": "infrastructure.cluster.x-k8s.io/v1beta1",
		"kind":       "GCPCluster",

View on GitHub (pinned to 4c8573c808)

Solutions

Make all subnets belong to the same GCP region
Split the multi-region deployment into separate clusters per region
Fix the subnet region values if they were set incorrectly

Example fix

// before
subnets:
- name: us-west1
  region: us-west1
- name: us-east1
  region: us-east1
// after
subnets:
- name: us-west1
  region: us-west1
- name: us-west1-b
  region: us-west1

Defensive patterns

Strategy: validation

Validate before calling

regions := map[string]bool{}
for _, s := range cluster.Spec.Subnets {
	regions[s.Region] = true
}
if len(regions) > 1 {
	return fmt.Errorf("CAPI GCP clusters must be single-region; found %d regions", len(regions))
}

Prevention

Keep all subnets of a CAPI-managed GCP cluster in one region
Split multi-region topologies across separate clusters
Validate region consistency before applying manifests

When it happens

Trigger: clusterScope.Apply() iterating Cluster.Spec.Subnets finds subnet[0].Region != subnet[i].Region for any i.

Common situations: Multi-region GCP cluster specs fed into the CAPI controller; copy-paste of subnet definitions from multi-region clusters; editing subnets to add a region for HA without understanding CAPI's single-region constraint.

Related errors

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/60f8f9d4cb1f55d7. Report an issue: GitHub.