kubernetes/kops · error

building full cluster spec: %w

Error message

building full cluster spec: %w

What it means

GetFullCluster calls cloudup.PopulateClusterSpec to fully populate/validate the cluster spec (defaults, cloud-specific fields) and wraps any failure. This means the cluster spec from the state store could not be reconciled against the cloud and instance groups.

Source

Thrown at pkg/commands/toolbox_enroll.go:535

	assetBuilder, err := b.GetAssetBuilder(ctx)
	if err != nil {
		return nil, err
	}

	instanceGroupList, err := b.GetInstanceGroups(ctx)
	if err != nil {
		return nil, err
	}

	var instanceGroups []*kops.InstanceGroup
	for i := range instanceGroupList.Items {
		instanceGroup := &instanceGroupList.Items[i]
		instanceGroups = append(instanceGroups, instanceGroup)
	}

	fullCluster, err := cloudup.PopulateClusterSpec(ctx, clientset, cluster, instanceGroups, cloud, assetBuilder)
	if err != nil {
		return nil, fmt.Errorf("building full cluster spec: %w", err)
	}
	b.fullCluster = fullCluster
	return fullCluster, nil
}

func (b *ConfigBuilder) GetInstanceGroup(ctx context.Context) (*kops.InstanceGroup, error) {
	if b.InstanceGroup != nil {
		return b.InstanceGroup, nil
	}

	instanceGroups, err := b.GetInstanceGroups(ctx)
	if err != nil {
		return nil, err
	}

	if b.InstanceGroupName == "" {
		return nil, fmt.Errorf("InstanceGroup name is missing")
	}

View on GitHub (pinned to 4c8573c808)

Solutions

1. Read the wrapped root cause (%w chain) — it names the specific spec field or cloud error
2. Validate the cluster: kops replace/apply with --dry-run or `kops toolbox template` to surface spec errors
3. Refresh cloud credentials and confirm the cloud API is reachable
4. Upgrade/align the cluster spec (kops upgrade cluster) if versions are mismatched

Example fix

// before
fullCluster, err := b.GetFullCluster(ctx) // opaque spec error
// after
if err != nil {
    var root error
    for errors.Unwrap(err) != nil { root = errors.Unwrap(err) }
    log.Printf("populate failed, root cause: %v", root)
}

// validate spec before populating
if err := cluster.Validate(false); err != nil { return fmt.Errorf("invalid cluster spec: %w", err) }

func isSpecPopulationError(err error) bool {
    return err != nil && strings.Contains(err.Error(), "building full cluster spec")
}

full, err := b.GetFullCluster(ctx)
if isSpecPopulationError(err) {
    return fmt.Errorf("fix cluster spec / cloud access (see wrapped cause): %w", err)
}

When it happens

Trigger: PopulateClusterSpec returns an error: invalid or missing fields in the cluster manifest, cloud API failures (auth, quota, region), unsupported kubernetes version, or inconsistent instance groups.

Common situations: Cluster spec edited by hand with invalid values; cloud credentials expired/missing; kops version newer than the spec supports; deleting cloud resources referenced by the cluster (subnets/VPC).

Related errors

• error populating configuration: %v
• validation of the full cluster and instance group specs fail
• error populating configuration: %v
• configuration must include Subnets
• must configure at least one Node InstanceGroup

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/c4650e812b48a3da. Report an issue: GitHub.