OpenTelemetry tracing add (default off, k8s me on)

Dockerfile

@@ -22,4 +22,12 @@ USER appuser
 EXPOSE 8000
 HEALTHCHECK --interval=30s --timeout=3s CMD python -c "import urllib.request;urllib.request.urlopen('http://127.0.0.1:8000/health')"
 
-CMD ["gunicorn", "--bind", "0.0.0.0:8000", "--workers", "2", "app.main:app"]
+# Tracing default OFF. k8s manifest me OTEL_SDK_DISABLED=false karke on hota hai,
+# taaki build/smoke test ke waqt export ki koshish na ho.
+ENV OTEL_SDK_DISABLED=true \
+    OTEL_TRACES_EXPORTER=otlp \
+    OTEL_METRICS_EXPORTER=none \
+    OTEL_LOGS_EXPORTER=none \
+    OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf
+
+CMD ["opentelemetry-instrument", "gunicorn", "--bind", "0.0.0.0:8000", "--workers", "2", "app.main:app"]

requirements.txt

@@ -1,2 +1,5 @@
-flask==3.0.3
-gunicorn==22.0.0
+flask
+gunicorn
+opentelemetry-distro
+opentelemetry-exporter-otlp-proto-http
+opentelemetry-instrumentation-flask