kubernetes/kops · error

unrecognized authentication config %v

Error message

unrecognized authentication config %v

What it means

Fallback guard at the end of writeAuthenticationConfig: the APIServerConfig.Authentication value matches none of the recognized types (e.g. aws-iam-authenticator or oidc settings), so no authentication config file can be generated.

Source

Thrown at nodeup/pkg/model/kube_apiserver.go:436

				Mode:     new("600"),
				Owner:    new("aws-iam-authenticator"),
				Group:    new("aws-iam-authenticator"),
			})

			c.AddTask(&nodetasks.File{
				Path:     "/srv/kubernetes/aws-iam-authenticator/key.pem",
				Contents: privateKey,
				Type:     nodetasks.FileType_File,
				Mode:     new("600"),
				Owner:    new("aws-iam-authenticator"),
				Group:    new("aws-iam-authenticator"),
			})
		}

		return nil
	}

	return fmt.Errorf("unrecognized authentication config %v", b.NodeupConfig.APIServerConfig.Authentication)
}

func (b *KubeAPIServerBuilder) writeServerCertificate(c *fi.NodeupModelBuilderContext, kubeAPIServer *kops.KubeAPIServerConfig) error {
	pathSrvKAPI := filepath.Join(b.PathSrvKubernetes(), "kube-apiserver")

	{
		// A few names used from inside the cluster, which all resolve the same based on our default suffixes
		alternateNames := []string{
			"kubernetes",
			"kubernetes.default",
			"kubernetes.default.svc",
			"kubernetes.default.svc." + b.NodeupConfig.APIServerConfig.ClusterDNSDomain,
		}

		// Names specified in the cluster spec
		if b.NodeupConfig.APIServerConfig.API.PublicName != "" {
			alternateNames = append(alternateNames, b.NodeupConfig.APIServerConfig.API.PublicName)
		}

View on GitHub (pinned to 4c8573c808)

Solutions

1. Check the authentication block in the cluster spec
2. Use a supported authentication configuration
3. Update kOps if a newer authentication type is expected

When it happens

Trigger: Thrown at nodeup/pkg/model/kube_apiserver.go:436 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

• Authentication and authorization failures — expired tokens, bad credentials, and missing scopes.

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/4f036bda17516bbb. Report an issue: GitHub.