Add method to set exporter request headers

README.md

@@ -21,7 +21,6 @@
 </p>
 
 <!-- TOC -->
-
 - [Etymology](#etymology)
 - [Installation](#installation)
 - [Tracing](#tracing)
@@ -136,6 +135,22 @@ configure_tracer(
 )
 ```
 
+### Setting headers for the exporter
+
+```python
+from troncos.tracing import configure_tracer, Exporter, ExporterType
+
+TRACE_HOST = "127.0.0.1" # Usually obtained from env variables.
+TRACE_PORT = "4317"
+
+configure_tracer(
+    enabled=False, # Set to True when TRACE_HOST is configured.
+    service_name='SERVICE_NAME',
+    endpoint=f"http://{TRACE_HOST}:{TRACE_PORT}",
+    exporter=Exporter(ExporterType.GRPC, headers={"my", "header"}),
+)
+```
+
 ### Instrument your code
 
 Manual instrumentation of your code is described in the [ddtrace docs](https://ddtrace.readthedocs.io/en/stable/basic_usage.html#manual-instrumentation).

tests/tracing/test_writer.py

@@ -4,7 +4,7 @@
 from ddtrace import Tracer
 from pytest_httpserver import HTTPServer
 
-from troncos.tracing._enums import Exporter
+from troncos.tracing._enums import Exporter, ExporterType
 from troncos.tracing._writer import OTELWriter
 
 
@@ -73,3 +73,28 @@ def test_exceptions(httpserver: HTTPServer) -> None:
     data = tracer_assert(httpserver)
     assert b"service.name\x12\x10\n\x0etest_exception" in data
     assert b"exception.type\x12\x19\n\x17builtins.AssertionError" in data
+
+
+def test_headers(httpserver: HTTPServer) -> None:
+    httpserver.expect_oneshot_request("/v1/trace").respond_with_data("OK")
+
+    tracer = Tracer()
+    tracer.configure(
+        writer=OTELWriter(
+            service_name="test_headers",
+            service_attributes={},
+            endpoint=httpserver.url_for("/v1/trace"),
+            exporter=Exporter(
+                exporter_type=ExporterType.HTTP, headers={"test-header": "works"}
+            ),
+        )
+    )
+
+    with tracer.trace("test"):
+        pass
+
+    tracer.flush()  # type: ignore[no-untyped-call]
+
+    assert len(httpserver.log), "We should have gotten 1 request"
+    req, _ = httpserver.log[0]
+    assert req.headers.get("test-header") == "works"

troncos/tracing/__init__.py

@@ -2,10 +2,10 @@
 
 import ddtrace
 
-from ._enums import Exporter
+from ._enums import Exporter, ExporterType
 from ._writer import OTELWriter
 
-__all__ = ["Exporter"]
+__all__ = ["Exporter", "ExporterType"]
 
 
 def configure_tracer(

troncos/tracing/_enums.py

@@ -1,6 +1,21 @@
 from enum import Enum
 
 
-class Exporter(Enum):
+class ExporterType(Enum):
     HTTP = "http"
     GRPC = "grpc"
+
+
+class Exporter:
+    HTTP: "Exporter" = None  # type: ignore[assignment]
+    GRPC: "Exporter" = None  # type: ignore[assignment]
+
+    def __init__(
+        self, exporter_type: ExporterType, headers: dict[str, str] | None = None
+    ) -> None:
+        self.exporter_type = exporter_type
+        self.headers = headers
+
+
+Exporter.HTTP = Exporter(ExporterType.HTTP)
+Exporter.GRPC = Exporter(ExporterType.GRPC)

troncos/tracing/_otel.py

@@ -13,7 +13,7 @@
 )
 from structlog import get_logger
 
-from ._enums import Exporter
+from ._enums import Exporter, ExporterType
 
 try:
     from opentelemetry.exporter.otlp.proto.grpc.trace_exporter import (
@@ -41,16 +41,16 @@ def get_otel_span_processors(
     span_exporter: SpanExporter
 
     # Exporter
-    if exporter == Exporter.HTTP:
-        span_exporter = HTTPSpanExporter(endpoint=endpoint)
-    elif exporter == Exporter.GRPC:
+    if exporter.exporter_type == ExporterType.HTTP:
+        span_exporter = HTTPSpanExporter(endpoint=endpoint, headers=exporter.headers)
+    elif exporter.exporter_type == ExporterType.GRPC:
         if GRPCSpanExporter is None:
             raise RuntimeError(
                 "opentelemetry-exporter-otlp-proto-grpc needs to be installed "
                 "to use the GRPC exporter."
             )
 
-        span_exporter = GRPCSpanExporter(endpoint=endpoint)
+        span_exporter = GRPCSpanExporter(endpoint=endpoint, headers=exporter.headers)
     else:
         raise RuntimeError("Unsupported span exporter.")