Empty test configuration (empty/)
=================================

The 'empty' test is a minimal configuration that loads the OTel filter without
defining any scopes, events or groups.  The instrumentation block contains only
the config directive pointing to the YAML pipeline definition.

This configuration verifies that the filter initializes and shuts down cleanly
when no telemetry is configured.  It exercises the full YAML parsing path
(exporters, processors, readers, samplers, providers and signals) without
producing any trace, metric or log-record data.


Files
-----

  empty/otel.cfg    OTel filter configuration (instrumentation only)
  empty/haproxy.cfg HAProxy frontend/backend configuration
  empty/otel.yml    Exporter, processor, reader and provider definitions


Events
------

  No events are registered.  The filter is loaded and attached to the frontend
  but performs no per-stream processing.


YAML pipeline
-------------

  Despite the empty filter configuration, the otel.yml file defines a complete
  pipeline with all three signal types to verify that the YAML parser handles
  the full configuration without errors:

    Signal     Exporter                   Processor / Reader
    -----------------------------------------------------------
    traces     exporter_traces_otlp_http  processor_traces_batch
    metrics    exporter_metrics_otlp_http reader_metrics
    logs       exporter_logs_otlp_http    processor_logs_batch

  Additional exporter definitions (otlp_file, otlp_grpc, ostream, memory,
  zipkin, elasticsearch) are present in the YAML but are not wired into the
  active signal pipelines.


Running the test
----------------

There is no dedicated run script for the empty configuration.  To run it
manually from the test/ directory:

  % /path/to/haproxy -f haproxy-common.cfg -f empty/haproxy.cfg
