[Trace] add opentelemetry (#2852)

* add opentelemetry

* add opentelemetry

* add opentelemetry on dequeue

* add opentelemetry on dequeue

* add opentelemetry on dequeue

---------

Co-authored-by: Jiang-Jia-Jun <163579578+Jiang-Jia-Jun@users.noreply.github.com>

fastdeploy/metrics/trace_util.py

@@ -0,0 +1,144 @@
+from opentelemetry.propagate import inject, extract
+from opentelemetry import trace
+
+import json
+import os
+
+# create global OpenTelemetry tracer
+tracer = trace.get_tracer(__name__)
+
+# OpenTelemetry Trace context store in metadata
+TRACE_CARRIER = "trace_carrier"
+
+def inject_to_metadata(request, metadata_attr='metadata'):
+    """
+        Inject OpenTelemetry trace context into the metadata field of the request.
+
+        Parameters:
+        request: can be a dict or object, with metadata attributes or fields.
+        metadata_attr: the field name of metadata, default is 'metadata'.
+
+        Operation:
+        - If metadata does not exist, create a new one and mount it on the request.
+        - Inject the current trace context as a JSON string and store it in metadata.
+        - Use the key TRACE_CARRIER to store the injected content.
+
+        Note:
+        - This function is a non-blocking operation, and errors are silently ignored.
+        - If there is no metadata attribute in the request, an empty dict will be created for it as its attribute
+    """
+    try:
+        if request is None:
+            return
+        if is_opentelemetry_instrumented() == False:
+            return
+
+        metadata = request.get(metadata_attr) if isinstance(request, dict) else getattr(request, metadata_attr, None)
+        if metadata is None:
+            metadata = {}
+            if isinstance(request, dict):
+                request[metadata_attr] = metadata
+            else:
+                setattr(request, metadata_attr, metadata)
+
+        trace_carrier = {}
+        inject(trace_carrier)
+        trace_carrier_json_string = json.dumps(trace_carrier)
+        metadata[TRACE_CARRIER] = trace_carrier_json_string
+    except:
+        pass
+
+def extract_from_metadata(request, metadata_attr='metadata'):
+    """
+        Extract trace context from metadata of request object (dict or class instance).
+
+        Parameters:
+        request: can be a dictionary or any object, containing metadata attributes or fields.
+        metadata_attr: metadata field name, default is 'metadata'.
+
+        Returns:
+        - Extraction success: returns OpenTelemetry context object (Context)
+        - Extraction failure or exception: returns None
+    """
+    try:
+        metadata = request.get(metadata_attr) if isinstance(request, dict) else getattr(request, metadata_attr, None)
+        if metadata is None:
+            return None
+
+        trace_carrier_json_string = metadata.get(TRACE_CARRIER)
+        if trace_carrier_json_string is None:
+            return None
+
+        trace_carrier = json.loads(trace_carrier_json_string)
+        ctx = extract(trace_carrier)
+        return ctx
+    except:
+        return None
+    
+
+def extract_from_request(request):
+    """
+        Extract trace context from trace_carrier of request object (dict or class instance).
+
+        Parameters:
+        request: can be a dictionary or any object, containing metadata attributes or fields.
+        metadata_attr: metadata field name, default is 'metadata'.
+
+        Returns:
+        - Extraction success: returns OpenTelemetry context object (Context)
+        - Extraction failure or exception: returns None
+    """
+    try:
+        trace_carrier_info = getattr(request, TRACE_CARRIER, None)
+
+        if trace_carrier_info is None:
+            return None
+
+        trace_carrier = json.loads(trace_carrier_info)
+        ctx = extract(trace_carrier)
+        return ctx
+    except:
+        return None
+
+def start_span(span_name, request, kind=trace.SpanKind.CLIENT):
+    """
+        just start a new span in request trace context
+    """
+    try:
+        if is_opentelemetry_instrumented() == False:
+            return
+        # extract Trace context from request.metadata.trace_carrier
+        ctx = extract_from_metadata(request)
+        with tracer.start_as_current_span(span_name, context=ctx, kind=kind) as span:
+            pass
+    except:
+        pass
+
+def start_span_request(span_name, request, kind=trace.SpanKind.CLIENT):
+    """
+        just start a new span in request trace context
+    """
+    try:
+        if is_opentelemetry_instrumented() == False:
+            return
+        # extract Trace context from request.metadata.trace_carrier
+        ctx = extract_from_request(request)
+        with tracer.start_as_current_span(span_name, context=ctx, kind=kind) as span:
+            pass
+    except:
+        pass
+
+def is_opentelemetry_instrumented() -> bool:
+    """
+        check OpenTelemetry is start or not
+    """
+    try:
+        return (
+            os.getenv("OTEL_PYTHONE_DISABLED_INSTRUMENTATIONS") is not None
+            or os.getenv("OTEL_SERVICE_NAME") is not None
+            or os.getenv("OTEL_TRACES_EXPORTER") is not None
+        )
+    except Exception:
+        return False
+    
+