xk6-output-opentelemetry

A work in progress k6 extension to output real-time test metrics in OpenTelemetry metrics format.

[!WARNING]
It's work in progress implementation and not ready for production use.

Configuration options

It's worth to mention that the extension is using the OpenTelemetry Go SDK that's why it's possible to use the configuration environment variables from the SDK. However, if the K6_OTEL_* environment variables are set, they will take precedence over the SDK configuration.

k6-specific configuration

• K6_OTEL_METRIC_PREFIX - Metric prefix. Default is empty.
• K6_OTEL_FLUSH_INTERVAL - How frequently to flush metrics from k6 metrics engine. Default is 1s.

OpenTelemetry-specific configuration

• K6_OTEL_EXPORT_INTERVAL - configures the intervening time between metrics exports. Default is 10s.
• K6_OTEL_EXPORTER_TYPE - metric exporter type. Default is grpc.
• K6_OTEL_HEADERS - headers in W3C Correlation-Context format without additional semi-colon delimited metadata (i.e. "k1=v1,k2=v2"). Passes the headers to the exporter.

TLS configuration

• K6_OTEL_TLS_INSECURE_SKIP_VERIFY - disables server certificate verification.
• K6_OTEL_TLS_CERTIFICATE - path to the certificate file for TLS credentials.
• K6_OTEL_TLS_CLIENT_CERTIFICATE - path to the client certificate file (must be PEM encoded data).
• K6_OTEL_TLS_CLIENT_KEY - path to the client key file (must be PEM encoded data).

If TLS configuration is provided, the exporter will use it.

GRPC exporter

• K6_OTEL_GRPC_EXPORTER_INSECURE - disables client transport security for the gRPC exporter.
• K6_OTEL_GRPC_EXPORTER_ENDPOINT - configures the gRPC exporter endpoint. Default is localhost:4317.

[!TIP] Also, you can use OpenTelemetry SDK configuration environment variables.

HTTP exporter

• K6_OTEL_HTTP_EXPORTER_INSECURE - disables client transport security for the HTTP exporter.
• K6_OTEL_HTTP_EXPORTER_ENDPOINT - configures the HTTP exporter endpoint. Default is localhost:4318.
• K6_OTEL_HTTP_EXPORTER_URL_PATH - configures the HTTP exporter path. Default is /v1/metrics.

[!TIP] Also, you can use OpenTelemetry SDK configuration environment variables.

Build

To build a k6 binary with this extension, first ensure you have the prerequisites:

• Go toolchain
• Git
• xk6

make build

This will result in a k6 binary in the current directory.

Local usage

1. You could run a local environment with OpenTelemetry collector (Grafana Alloy), Prometheus backend and Grafana (http://localhost:3000/):

docker-compose up -d

2. Run with the just build `k6:

 K6_OTEL_GRPC_EXPORTER_INSECURE=true K6_OTEL_METRIC_PREFIX=k6_ ./k6 run --tag testid=1 -o xk6-opentelemetry examples/script.js

3. Open Grafana http://localhost:3000/ and navigate to the k6 OpenTelemetry Prometheus dashboard.