grafana/k6 · error

providing service version is required

Error message

providing service version is required

What it means

The OpenTelemetry metrics output requires a service version for the exported resource. k6 defaults it to the k6 build version, but Validate() rejects the config when ServiceVersion.String is empty — typically because K6_OTEL_SERVICE_VERSION or the JSON output config overrode the default with an empty string. The code even carries a TODO noting the requirement is arguably artificial, but it is enforced.

Solutions

1. Set a real value, e.g. export K6_OTEL_SERVICE_VERSION=1.4.2
2. Remove the empty K6_OTEL_SERVICE_VERSION from the environment so the k6 version default applies
3. Populate the variable from the build metadata you already have (git describe, package version) in CI

Example fix

# before
export K6_OTEL_SERVICE_VERSION=
k6 run -o opentelemetry script.js
# after
export K6_OTEL_SERVICE_VERSION=$(git describe --tags --always)
k6 run -o opentelemetry script.js

// Shell: treat empty as unset (falls back to k6's version)
[ -z "${K6_OTEL_SERVICE_VERSION:-}" ] && unset K6_OTEL_SERVICE_VERSION
export K6_OTEL_SERVICE_VERSION="${K6_OTEL_SERVICE_VERSION:-$(git describe --tags --always 2>/dev/null || echo dev)}"
k6 run -o opentelemetry script.js

When it happens

Trigger: export K6_OTEL_SERVICE_VERSION= (defined but empty); an output config JSON with "serviceVersion": "".

Common situations: CI placeholder variables left empty; pipelines that set the version only for release builds and leave it blank in dev jobs.

Related errors

• providing service name is required
• both K6_CLOUD_METRICS_PUSH_URL and K6_CLOUD_TEST_RUN_TOKEN…
• failed to append root certificate to the pool
• gRPC exporter endpoint is required
• grpc protocol does not support URL path

AI-assisted analysis of grafana/k6@01ffac6f24 (2026-08-18). Data as JSON: /api/errors/7bec815ad628969b. Report an issue: GitHub.

Appendix: source

Thrown at internal/output/opentelemetry/config.go:215

		cfg.HTTPUsername = v.HTTPUsername
	}

	if v.HTTPPassword.Valid {
		cfg.HTTPPassword = v.HTTPPassword
	}

	return cfg
}

// Validate validates the config
func (cfg Config) Validate() error {
	if cfg.ServiceName.String == "" {
		return errors.New("providing service name is required")
	}
	// TODO: it's not actually required, but we should probably have a default
	// check if it works without it
	if cfg.ServiceVersion.String == "" {
		return errors.New("providing service version is required")
	}
	if err := cfg.validateExporterProtocol(); err != nil {
		return err
	}
	return nil
}

func (cfg Config) validateExporterProtocol() error {
	if cfg.ExporterProtocol.String != "" {
		if cfg.ExporterProtocol.String != grpcExporterProtocol && cfg.ExporterProtocol.String != httpExporterProtocol {
			return fmt.Errorf(
				"unsupported exporter protocol %q, only %q and %q are supported",
				cfg.ExporterProtocol.String,
				grpcExporterProtocol,
				httpExporterProtocol,
			)
		}
		switch cfg.ExporterProtocol.String {

View on GitHub (pinned to 01ffac6f24)