kubernetes/kops · error

listing front-ends for load-balancer %s: %w

Error message

listing front-ends for load-balancer %s: %w

What it means

kOps wraps failures from `lbService.ListFrontends` when the LoadBalancerFrontend task's Find looks up the existing front-end by name for the load-balancer. The error comes from the Scaleway LB Zoned API, not from the 'not found' case (that returns nil, nil when TotalCount != 1). Thrown in Find of lb_frontend.go.

Source

Thrown at upup/pkg/fi/cloudup/scalewaytasks/lb_frontend.go:82

func (l *LBFrontend) CompareWithID() *string {
	return l.ID
}

func (l *LBFrontend) Find(context *fi.CloudupContext) (*LBFrontend, error) {
	cloud := context.T.Cloud.(scaleway.ScwCloud)
	lbService := cloud.LBService()

	if l.LoadBalancer.LBID == nil {
		return nil, nil
	}

	frontendResponse, err := lbService.ListFrontends(&lb.ZonedAPIListFrontendsRequest{
		Zone: scw.Zone(cloud.Zone()),
		LBID: fi.ValueOf(l.LoadBalancer.LBID),
		Name: l.Name,
	})
	if err != nil {
		return nil, fmt.Errorf("listing front-ends for load-balancer %s: %w", fi.ValueOf(l.LoadBalancer.LBID), err)
	}
	if frontendResponse.TotalCount != 1 {
		return nil, nil
	}
	frontend := frontendResponse.Frontends[0]

	return &LBFrontend{
		Name:        new(frontend.Name),
		Lifecycle:   l.Lifecycle,
		ID:          new(frontend.ID),
		Zone:        new(string(frontend.LB.Zone)),
		InboundPort: new(frontend.InboundPort),
		LoadBalancer: &LoadBalancer{
			Name: new(frontend.LB.Name),
		},
		LBBackend: &LBBackend{
			Name: new(frontend.Backend.Name),
			ID:   new(frontend.Backend.ID),

View on GitHub (pinned to 4c8573c808)

Solutions

1. Rerun `kops update cluster` — often transient
2. Verify the LB exists at the configured zone and LBID in the Scaleway console
3. Confirm cloud zone configuration matches the LB's zone
4. Check Scaleway credentials/permissions for the LB API
5. Inspect wrapped scw error (e.g. 404 not_found vs 403 permissions) for the precise cause

Example fix

// before: no diagnostics of cause
return nil, fmt.Errorf("listing front-ends for load-balancer %s: %w", lbID, err)
// after: classify the SDK error
var serr *scw.ResponseError
if errors.As(err, &serr) && serr.Status == 404 {
    return nil, nil // LB gone; treat as not found
}
return nil, fmt.Errorf("listing front-ends for load-balancer %s: %w", lbID, err)

// confirm LB is reachable before listing its front-ends
lbs, err := lbService.ListLBs(&lb.ZonedAPIListLBsRequest{Zone: scw.Zone(cloud.Zone()), Name: lbName}, scw.WithAllPages())
if err != nil { return err }
if lbs.TotalCount != 1 { return nil } // LB gone; nothing to find

func lbNotFound(err error) bool {
    var serr *scw.ResponseError
    return errors.As(err, &serr) && serr.Status == 404
}

if err != nil {
    if lbNotFound(err) { return nil, nil } // treat as absent
    return nil, fmt.Errorf("listing front-ends for load-balancer %s: %w", lbID, err)
}

When it happens

Trigger: Find calls ListFrontends with Zone=scw.Zone(cloud.Zone()), LBID=l.LoadBalancer.LBID, Name=l.Name; the list call itself fails — invalid LBID, zone mismatch between cloud and LB, auth failure, or API outage.

Common situations: LB was deleted out-of-band so LBID is stale; cloud.Zone() returns a different zone than where the LB lives; expired Scaleway credentials; network partition during reconcile.

Related errors

• getting load-balancer %s: %w
• waiting for load-balancer: %w
• deleting load-balancer %s: %w
• updating back-end server IPs for load-balancer %s: %w
• creating back-end for load-balancer %s: %w

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/571caa01083cdf32. Report an issue: GitHub.