apiVersion: v1
kind: ConfigMap
metadata:
  name: my-python-app
  namespace: meta
data:
  main.py: |
    import time
    import random
    from flask import Flask
    from opentelemetry import trace
    from opentelemetry.sdk.trace import TracerProvider
    from opentelemetry.sdk.trace.export import BatchSpanProcessor
    from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
    from opentelemetry.instrumentation.flask import FlaskInstrumentor
    from opentelemetry.sdk.resources import Resource
    import logging
    from opentelemetry.trace import get_current_span
    SERVICE_NAME = "my-flask-app"  # match your OTEL resource name



    trace.set_tracer_provider(
        TracerProvider(resource=Resource.create({"service.name": "my-flask-app"}))
    )
    tracer = trace.get_tracer(__name__)
    span_processor = BatchSpanProcessor(OTLPSpanExporter())
    trace.get_tracer_provider().add_span_processor(span_processor)



    class TraceIdFilter(logging.Filter):
        def filter(self, record):
            span = trace.get_current_span()
            ctx = span.get_span_context()
            if ctx.trace_id != 0:
                record.trace_id = format(ctx.trace_id, "032x")
                record.span_id = format(ctx.span_id, "016x")
                record.service_name = SERVICE_NAME
            else:
                record.trace_id = None
                record.span_id = None
            return True


    formatter = logging.Formatter(
        '{"message": "%(message)s", "trace_id": "%(trace_id)s", "span_id": "%(span_id)s", "service_name": "my-flask-app"}'
    )
    handler = logging.StreamHandler()
    handler.setFormatter(formatter)
    handler.addFilter(TraceIdFilter())

    logger = logging.getLogger("myapp")
    logger.setLevel(logging.INFO)
    logger.addHandler(handler)


    resource = Resource(
        attributes={
            "service.name": "python-otel-demo-app",  # 👈 choose any name you like
        }
    )
    trace.set_tracer_provider(TracerProvider(resource=resource))
    tracer = trace.get_tracer(__name__)


    otlp_exporter = OTLPSpanExporter(
        endpoint="http://otel-collector.meta.svc:4318/v1/traces",
        # insecure=True,
    )
    span_processor = BatchSpanProcessor(otlp_exporter)
    trace.get_tracer_provider().add_span_processor(span_processor)


    app = Flask(__name__)
    FlaskInstrumentor().instrument_app(app)


    def get_trace_id():
        span = get_current_span()
        if span:
            return span.get_span_context().trace_id
        return None


    @app.route("/")
    def root():
        with tracer.start_as_current_span("handle_homepage"):
            logger.info("handling request", extra={"trace_id": get_trace_id()})
            time.sleep(random.random() * 0.05)  # simulate request parsing
            fetch_user()
            calculate_recommendations()
            return "Hello from / with traces!"


    def fetch_user():
        with tracer.start_as_current_span("fetch_user"):
            time.sleep(random.random() * 0.1)  # simulate DB query


    def calculate_recommendations():
        with tracer.start_as_current_span("calculate_recommendations"):
            for i in range(2):
                with tracer.start_as_current_span(f"score_item_{i}"):
                    time.sleep(random.random())


    if __name__ == "__main__":
        app.run(host="0.0.0.0", port=5000)
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: python-otel
  namespace: meta
  labels:
    app: python-otel
spec:
  replicas: 1
  selector:
    matchLabels:
      app: python-otel
  template:
    metadata:
      labels:
        app: python-otel
    spec:
      containers:
        - name: python
          image: python
          command: ["/bin/sh", "-c"]
          args:
            - |
              python -m venv .venv && \
              .venv/bin/python -m pip install --upgrade pip && \
              .venv/bin/python -m pip install \
                opentelemetry-sdk \
                opentelemetry-exporter-otlp \
                opentelemetry-instrumentation-flask \
                flask && \
              .venv/bin/python /app/main.py
          volumeMounts:
            - name: app-code
              mountPath: /app
          env:
            - name: OTEL_EXPORTER_OTLP_ENDPOINT
              value: http://otel-collector.meta.svc:4318
            - name: OTEL_EXPORTER_OTLP_INSECURE
              value: "true"
      volumes:
        - name: app-code
          configMap:
            name: my-python-app
---
apiVersion: v1
kind: Service
metadata:
  name: python-otel
  namespace: meta
spec:
  selector:
    app: python-otel
  ports:
    - port: 80
      targetPort: 5000