kubernetes/kops · error

failed to find instance type details on: %s, error: %s

Error message

failed to find instance type details on: %s, error: %s

What it means

buildEphemeralDevices resolves instance-type metadata (via awsup.GetMachineTypeInfo) to map ephemeral device names to block device mappings; when the machine type cannot be found in the instance-type metadata it returns this error. It means kOps has no topology data for the given ec2 InstanceType.

Source

Thrown at upup/pkg/fi/cloudup/awstasks/helper.go:34

package awstasks

import (
	"errors"
	"fmt"

	ec2types "github.com/aws/aws-sdk-go-v2/service/ec2/types"
	"k8s.io/kops/upup/pkg/fi/cloudup/awsup"
)

// buildEphemeralDevices looks up the machine type and discovery any ephemeral device mappings
func buildEphemeralDevices(cloud awsup.AWSCloud, machineType ec2types.InstanceType) (map[string]*BlockDeviceMapping, error) {
	if machineType == "" {
		return nil, nil
	}
	mt, err := awsup.GetMachineTypeInfo(cloud, machineType)
	if err != nil {
		return nil, fmt.Errorf("failed to find instance type details on: %s, error: %s", machineType, err)
	}

	blockDeviceMappings := make(map[string]*BlockDeviceMapping)

	for _, ed := range mt.EphemeralDevices() {
		blockDeviceMappings[ed.DeviceName] = &BlockDeviceMapping{VirtualName: new(ed.VirtualName)}
	}

	return blockDeviceMappings, nil
}

// buildAdditionalDevices is responsible for creating additional volumes in this lc
func buildAdditionalDevices(volumes []*BlockDeviceMapping) (map[string]*BlockDeviceMapping, error) {
	devices := make(map[string]*BlockDeviceMapping)

	// @step: iterate the volumes and create devices from them
	for _, x := range volumes {
		if x.DeviceName == nil {

View on GitHub (pinned to 4c8573c808)

Solutions

1. Fix the instance type name in the cluster/instance-group spec (check spelling and generation, e.g. m5.large).
2. Upgrade kOps to a release whose instance type metadata includes the new family.
3. If the type genuinely has no instance-store volumes, avoid relying on ephemeral device mappings (use EBS-backed storage).

Example fix

// before
machineType: m6a.larg
// after
machineType: m6a.large

// Pre-check instance type against kops supported types
kops get instancegroups --name <cluster> -o yaml | grep machineType
# or validate locally before apply:
machineType=$(yq '.spec.machineType' ig.yaml)
aws ec2 describe-instance-types --instance-types "$machineType" >/dev/null || echo "unknown instance type"

func validInstanceType(mt ec2types.InstanceType) bool {
    return mt != "" && strings.Contains(string(mt), ".") && len(strings.Split(string(mt), ".")) == 2
}

When it happens

Trigger: GetMachineTypeInfo errors because the instance type string is unknown/unsupported in the bundled metadata (e.g. typo, new generation not yet in kOps' instance type data, or wrong region family).

Common situations: Typo in the machineType in the InstanceGroup spec; using a brand-new instance family on an older kOps release; custom fork with outdated aws-instance-types data.

Related errors

• DIGITALOCEAN_ACCESS_TOKEN is required
• timed out waiting for volume to detach
• DeviceName not set for volume
• unexpected number of network interfaces for instance %q: %v
• unexpected amount of ipv6 prefixes on interface %q: %v

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/36d815f9f719c27d. Report an issue: GitHub.