derailed/k9s · error

expecting DaemonSet resource

Error message

expecting DaemonSet resource

What it means

k9s's DaemonSet DAO fetches a single DaemonSet from the shared informer cache as *unstructured.Unstructured and converts it into appsv1.DaemonSet via runtime.DefaultUnstructuredConverter.FromUnstructured (internal/dao/ds.go:133). The sentinel 'expecting DaemonSet resource' is returned when conversion fails, and the underlying converter error is discarded. It means the cached object under daemonsets.apps does not fit the k8s.io/api schema k9s was compiled against.

Source

Thrown at internal/dao/ds.go:133

	ds, err := d.GetInstance(fqn)
	if err != nil {
		return "", err
	}

	return podFromSelector(d.Factory, ds.Namespace, ds.Spec.Selector.MatchLabels)
}

// GetInstance returns a daemonset instance.
func (d *DaemonSet) GetInstance(fqn string) (*appsv1.DaemonSet, error) {
	o, err := d.getFactory().Get(d.gvr, fqn, true, labels.Everything())
	if err != nil {
		return nil, err
	}

	var ds appsv1.DaemonSet
	err = runtime.DefaultUnstructuredConverter.FromUnstructured(o.(*unstructured.Unstructured).Object, &ds)
	if err != nil {
		return nil, errors.New("expecting DaemonSet resource")
	}

	return &ds, nil
}

// ScanSA scans for serviceaccount refs.
func (d *DaemonSet) ScanSA(_ context.Context, fqn string, wait bool) (Refs, error) {
	ns, n := client.Namespaced(fqn)
	oo, err := d.getFactory().List(d.gvr, ns, wait, labels.Everything())
	if err != nil {
		return nil, err
	}

	refs := make(Refs, 0, len(oo))
	for _, o := range oo {
		var ds appsv1.DaemonSet
		err = runtime.DefaultUnstructuredConverter.FromUnstructured(o.(*unstructured.Unstructured).Object, &ds)
		if err != nil {

View on GitHub (pinned to 2d3ccc6ba2)

Solutions

1. Inspect the object: kubectl get daemonset.apps <name> -n <ns> -o yaml and fix mistyped or unexpected fields.
2. Upgrade k9s so its vendored k8s.io/* versions match the cluster minor version.
3. Verify daemonsets.apps is served by the core apiserver and not shadowed by an aggregated service.
4. Restart k9s to rebuild informer caches after cluster/webhook changes.
5. If embedding, wrap the converter error with %w to expose the offending field.

Example fix

// before
err = runtime.DefaultUnstructuredConverter.FromUnstructured(o.(*unstructured.Unstructured).Object, &ds)
if err != nil {
    return nil, errors.New("expecting DaemonSet resource")
}
// after
u, ok := o.(*unstructured.Unstructured)
if !ok {
    return nil, fmt.Errorf("expected unstructured daemonset, got %T", o)
}
var ds appsv1.DaemonSet
if err := runtime.DefaultUnstructuredConverter.FromUnstructured(u.Object, &ds); err != nil {
    return nil, fmt.Errorf("daemonset %q does not match v1 schema: %w", fqn, err)
}

o, err := factory.Get(client.DsGVR, fqn, true, labels.Everything())
if err != nil { return err }
u, ok := o.(*unstructured.Unstructured)
if !ok || u.GroupVersionKind().Kind != "DaemonSet" {
    return fmt.Errorf("not a daemonset: %s", u.GroupVersionKind())
}

func isDaemonSet(o runtime.Object) bool {
    u, ok := o.(*unstructured.Unstructured)
    return ok && u.GroupVersionKind().Kind == "DaemonSet" && u.GroupVersionKind().Group == "apps"
}

var ds appsv1.DaemonSet
if err := runtime.DefaultUnstructuredConverter.FromUnstructured(u.Object, &ds); err != nil {
    return nil, fmt.Errorf("daemonset %q conversion: %w", fqn, err)
}

When it happens

Trigger: Calling dao.DaemonSet.GetInstance(fqn) — the daemonset detail view, restart or rollout actions — when the stored object has fields whose JSON types cannot be assigned to the compiled appsv1.DaemonSet struct: apiserver version skew, an aggregated API shadowing daemonsets.apps, or webhook-written out-of-schema values.

Common situations: k9s builds with older k8s.io/* libraries against newer clusters; DaemonSets mutated by custom controllers or webhooks with legacy fields; cache staleness right after cluster upgrades; embedding the DAO layer with a custom factory.

Related errors

• expecting cronjob resource
• expecting Deployment resource
• expecting StatefulSet resource
• expecting Job resource
• expecting ServiceAccount resource

AI-assisted analysis of derailed/k9s@2d3ccc6ba2 (2026-08-15). Data as JSON: /api/errors/74b404ced74ffcbe. Report an issue: GitHub.