kubernetes/kops · error

error parsing subnet url %q: %w

Error message

error parsing subnet url %q: %w

What it means

buildUsed iterates over the set of subnet self-link URLs known to the cluster and calls ParseGoogleCloudURL on each to extract the region. If a URL does not match the expected Google Cloud resource URL shape, this error is thrown with the offending URL. It means the cluster spec holds a subnet reference the URL parser cannot understand.

Source

Thrown at upup/pkg/fi/cloudup/gce/network.go:122

	if network == nil {
		return used, nil
	}

	subnetURLs := make(map[string]bool)
	for _, subnet := range network.Subnetworks {
		subnetURLs[subnet] = true
	}
	if len(subnetURLs) == 0 {
		return used, nil
	}

	klog.Infof("scanning regions for subnetwork CIDR allocations")

	regions := make(map[string]bool)
	for subnetURL := range subnetURLs {
		u, err := ParseGoogleCloudURL(subnetURL)
		if err != nil {
			return nil, fmt.Errorf("error parsing subnet url %q: %w", subnetURL, err)
		}
		regions[u.Region] = true
	}

	var subnets []*compute.Subnetwork
	for region := range regions {
		l, err := cloud.Compute().Subnetworks().List(ctx, cloud.Project(), region)
		if err != nil {
			return nil, fmt.Errorf("error listing Subnetworks in region %q: %w", region, err)
		}
		subnets = append(subnets, l...)
	}

	for _, subnet := range subnets {
		if !subnetURLs[subnet.SelfLink] {
			continue
		}
		if err := used.MarkInUse(subnet.IpCidrRange); err != nil {

View on GitHub (pinned to 4c8573c808)

Solutions

1. Verify each spec subnet value is a valid full self-link like https://www.googleapis.com/compute/v1/projects/P/regions/R/subnetworks/N
2. Regenerate the cluster spec from a known-good state (kops get cluster -o yaml from a working cluster)
3. Check ParseGoogleCloudURL expectations in upup/pkg/fi/cloudup/gce and correct the URL format accordingly
4. If values came from an older version, run kops update cluster with a current kops to normalize the spec

Example fix

// before
subnets:
  - id: my-subnet
// after
subnets:
  - id: https://www.googleapis.com/compute/v1/projects/my-project/regions/us-central1/subnetworks/my-subnet

func validateSubnetURLs(urls map[string]bool) error {
	for u := range urls {
		if _, err := gce.ParseGoogleCloudURL(u); err != nil {
			return fmt.Errorf("subnet %q is not a valid GCE URL: %w", u, err)
		}
	}
	return nil
}

used, err := buildUsed(ctx, cluster, cloud)
if err != nil {
	var raw string
	if strings.Contains(err.Error(), "error parsing subnet url") {
		fmt.Sscanf(err.Error(), "error parsing subnet url %q", &raw) // inspect and fix spec
	}
	return err
}

When it happens

Trigger: A subnet ID in the cluster spec that is not a well-formed Google Cloud self-link (e.g. a bare subnet name, a malformed regional URL, or a URL from a different API version shape that ParseGoogleCloudURL does not recognize), passed during IP-alias or subnet assignment.

Common situations: Hand-editing subnet IDs in the cluster spec; subnet values written by an older kops version in a URL format no longer parsed; copy/paste errors truncating the self-link.

Related errors

• failed to parse subnet CIDR %q: %w
• unable to parse instance url %q
• error listing subnetworks: %v
• invalid google cloud URL (content after name): %q
• error listing Subnetworks in region %q: %w

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/a04965c71673e9e6. Report an issue: GitHub.