feature: add gunicorn integration

Author: edisile

entrypoint

@@ -8,4 +8,9 @@ if [ "${FLASK_DEBUG}" = true ] || [ "${FLASK_DEBUG}" = 1 ]; then
     RUN_COMMAND="${RUN_COMMAND} --reload --log-level debug --timeout 9999"
 fi
 
+# if OTEL_SERVICE_NAME is defined, inject OTEL sdk
+if [ -n "${OTEL_SERVICE_NAME}" ]; then
+    RUN_COMMAND="${RUN_COMMAND} --config observability/observability.gunicorn.conf.py"
+fi
+
 ${RUN_COMMAND}

observability/observability.gunicorn.conf.py

@@ -0,0 +1,10 @@
+from opentelemetry import trace
+from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
+from opentelemetry.sdk.trace import TracerProvider
+from opentelemetry.sdk.trace.export import BatchSpanProcessor
+
+
+def post_fork(server, worker):
+    trace.set_tracer_provider(TracerProvider())
+    span_processor = BatchSpanProcessor(OTLPSpanExporter())
+    trace.get_tracer_provider().add_span_processor(span_processor)