Introduce Context.suppress_instrumentation (#181)

ext/opentelemetry-ext-http-requests/src/opentelemetry/ext/http_requests/__init__.py

@@ -23,6 +23,7 @@
 from requests.sessions import Session
 
 from opentelemetry import propagators
+from opentelemetry.context import Context
 from opentelemetry.trace import SpanKind
 
 
@@ -50,8 +51,8 @@ def enable(tracer):
 
     @functools.wraps(wrapped)
     def instrumented_request(self, method, url, *args, **kwargs):
-        # TODO: Check if we are in an exporter, cf. OpenCensus
-        # execution_context.is_exporter()
+        if Context.suppress_instrumentation:
+            return wrapped(self, method, url, *args, **kwargs)
 
         # See
         # https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/data-semantic-conventions.md#http-client

opentelemetry-sdk/src/opentelemetry/sdk/trace/export/__init__.py

@@ -18,6 +18,7 @@
 import typing
 from enum import Enum
 
+from opentelemetry.context import Context
 from opentelemetry.sdk import util
 
 from .. import Span, SpanProcessor
@@ -72,11 +73,15 @@ def on_start(self, span: Span) -> None:
         pass
 
     def on_end(self, span: Span) -> None:
+        suppress_instrumentation = Context.suppress_instrumentation
         try:
+            Context.suppress_instrumentation = True
             self.span_exporter.export((span,))
         # pylint: disable=broad-except
         except Exception as exc:
             logger.warning("Exception while exporting data: %s", exc)
+        finally:
+            Context.suppress_instrumentation = suppress_instrumentation
 
     def shutdown(self) -> None:
         self.span_exporter.shutdown()
@@ -176,11 +181,15 @@ def export(self) -> bool:
         while idx < self.max_export_batch_size and self.queue:
             self.spans_list[idx] = self.queue.pop()
             idx += 1
+        suppress_instrumentation = Context.suppress_instrumentation
         try:
+            Context.suppress_instrumentation = True
             self.span_exporter.export(self.spans_list[:idx])
         # pylint: disable=broad-except
         except Exception:
             logger.exception("Exception while exporting data.")
+        finally:
+            Context.suppress_instrumentation = suppress_instrumentation
 
         # clean up list
         for index in range(idx):