kubernetes/kops · error

unknown metadata type: %q in %q

Error message

unknown metadata type: %q in %q

What it means

When ReadFile sees a metadata:// URL, it dispatches on u.Host to a known cloud metadata provider (gce, aws, digitalocean, openstack). If the host segment names no supported provider, the library has no metadata endpoint mapping and returns this error.

Source

Thrown at util/pkg/vfs/context.go:152

		switch u.Scheme {
		case "metadata":
			switch u.Host {
			case "gce":
				httpURL := "http://169.254.169.254/computeMetadata/v1/" + u.Path
				httpHeaders := make(map[string]string)
				httpHeaders["Metadata-Flavor"] = "Google"
				return c.readHTTPLocation(httpURL, httpHeaders, opts)
			case "aws":
				return c.readAWSMetadata(ctx, u.Path)
			case "digitalocean":
				httpURL := "http://169.254.169.254/metadata/v1" + u.Path
				return c.readHTTPLocation(httpURL, nil, opts)
			case "openstack":
				httpURL := "http://169.254.169.254/latest/meta-data/" + u.Path
				return c.readHTTPLocation(httpURL, nil, opts)
			default:
				return nil, fmt.Errorf("unknown metadata type: %q in %q", u.Host, location)
			}

		case "http", "https":
			return c.readHTTPLocation(location, nil, opts)
		}
	}

	location = strings.TrimPrefix(location, "file://")

	p, err := c.BuildVfsPath(location)
	if err != nil {
		return nil, err
	}
	return p.ReadFile(ctx)
}

func (c *VFSContext) BuildVfsPath(p string) (Path, error) {
	// NOTE: we do not want this function to take a context.Context, we consider this a "builder".

View on GitHub (pinned to 4c8573c808)

Solutions

1. Use one of the supported hosts: metadata://gce/..., metadata://aws/..., metadata://digitalocean/..., metadata://openstack/...
2. Check spelling/casing of the provider segment immediately after metadata://
3. For unsupported clouds, query the metadata service directly via its http(s) URL instead of the metadata scheme
4. If you need a new provider, extend the switch in VFSContext.ReadFile in util/pkg/vfs/context.go

Example fix

// before
vfs.Context.ReadFile("metadata://azure/instance/compute")
// after
vfs.Context.ReadFile("metadata://openstack/latest/meta-data/instance-id") // supported host

var supportedMetadataHosts = map[string]bool{"gce": true, "aws": true, "digitalocean": true, "openstack": true}
func validateMetadataURL(loc string) error {
	u, err := url.Parse(loc)
	if err != nil || u.Scheme != "metadata" {
		return nil // not this error's concern
	}
	if !supportedMetadataHosts[u.Host] {
		return fmt.Errorf("unsupported metadata host %q (supported: gce, aws, digitalocean, openstack)", u.Host)
	}
	return nil
}

func isKnownMetadataHost(loc string) bool {
	u, err := url.Parse(loc)
	return err == nil && u.Scheme == "metadata" &&
		(u.Host == "gce" || u.Host == "aws" || u.Host == "digitalocean" || u.Host == "openstack")
}

data, err := vfs.Context.ReadFile(loc)
if err != nil && strings.Contains(err.Error(), "unknown metadata type") {
	return fmt.Errorf("metadata scheme supports only gce/aws/digitalocean/openstack: %w", err)
}

When it happens

Trigger: Calling ReadFile with metadata://<unknown-host>/... - e.g. metadata://azure/instance/compute, metadata://aliyun/meta-data/instance-id, or metadata:///instance-id (empty host, because the second slash set is missing so the path lands in Host incorrectly).

Common situations: Porting scripts written for another cloud to kOps; mistyping the provider name; forgetting that azure is not supported in the metadata scheme and using metadata://azure instead of the azure IMDS URL directly.

Related errors

• ReadOnlyError
• error reading addons from %q: %v
• error loading channel %q: %v
• unexpected kind for cluster, got %T, want kops.Cluster
• method ConfigBaseFor not supported in server-side client

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/8854eb6b8f5e0747. Report an issue: GitHub.