grafana/k6 · error

parse JSON options failed: %w

Error message

parse JSON options failed: %w

What it means

The OpenTelemetry output's JSON configuration (options.ext or K6_OTEL_* JSON config) could not be unmarshalled into the OTel Config struct. GetConsolidatedConfig wraps the JSON decode error; the raw JSON has invalid syntax or wrong-typed fields.

Source

Thrown at internal/output/opentelemetry/config.go:87

	HTTPPassword null.String `json:"password" envconfig:"K6_OTEL_HTTP_EXPORTER_PASSWORD"`

	// GRPCExporterEndpoint sets the target endpoint the OpenTelemetry Exporter
	// will connect to.
	GRPCExporterEndpoint null.String `json:"grpcExporterEndpoint" envconfig:"K6_OTEL_GRPC_EXPORTER_ENDPOINT"`
	// GRPCExporterInsecure disables client transport security for the Exporter's gRPC
	// connection.
	GRPCExporterInsecure null.Bool `json:"grpcExporterInsecure" envconfig:"K6_OTEL_GRPC_EXPORTER_INSECURE"`
}

// GetConsolidatedConfig combines the options' values from the different sources
// and returns the merged options. The Order of precedence used is documented
// in the k6 Documentation https://grafana.com/docs/k6/latest/using-k6/k6-options/how-to/#order-of-precedence.
func GetConsolidatedConfig(jsonRawConf json.RawMessage, env map[string]string) (Config, error) {
	cfg := newDefaultConfig()
	if jsonRawConf != nil {
		jsonConf, err := parseJSON(jsonRawConf)
		if err != nil {
			return cfg, fmt.Errorf("parse JSON options failed: %w", err)
		}
		cfg = cfg.Apply(jsonConf)
	}

	if len(env) > 0 {
		envConf, err := parseEnvs(env)
		if err != nil {
			return cfg, fmt.Errorf("parse environment variables options failed: %w", err)
		}
		cfg = cfg.Apply(envConf)
	}

	if err := cfg.Validate(); err != nil {
		// TODO: check why k6's still exiting with 255
		return cfg, errext.WithExitCodeIfNone(
			fmt.Errorf("error validating OpenTelemetry output config: %w", err),
			exitcodes.InvalidConfig,
		)

View on GitHub (pinned to 01ffac6f24)

Solutions

1. Validate the JSON syntax of the opentelemetry extension options
2. Make sure each field's value type matches the expected string/bool/number type

When it happens

Trigger: Thrown at internal/output/opentelemetry/config.go:87 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of grafana/k6@01ffac6f24 (2026-08-18). Data as JSON: /api/errors/da04798305d0b935. Report an issue: GitHub.