[Issue open-telemetry#1107] Add support for gzip compression for OTLP exporter

Author: wilguo

exporter/opentelemetry-exporter-otlp/src/opentelemetry/exporter/otlp/exporter.py

@@ -31,6 +31,7 @@
     StatusCode,
     insecure_channel,
     secure_channel,
+    Compression
 )
 
 from opentelemetry.proto.common.v1.common_pb2 import AnyValue, KeyValue
@@ -126,6 +127,7 @@ class OTLPExporterMixin(
         endpoint: OpenTelemetry Collector receiver endpoint
         credentials: ChannelCredentials object for server authentication
         metadata: Metadata to send when exporting
+        compression: Compression algorithm used in channel
     """
 
     def __init__(
@@ -140,12 +142,10 @@ def __init__(
         self._metadata = metadata
         self._collector_span_kwargs = None
 
-        if compression is None:
-            self.compression = os.environ.get(
-                "OTEL_EXPORTER_OTLP_COMPRESSION", DEFAULT_COMPRESSION
-            )
+        if compression is 'gzip':
+            self.compression = Compression.Gzip
         else:
-            self.compression = compression
+            self.compression = Compression.NoCompression
 
         if credentials is None:
             self._client = self._stub(insecure_channel(endpoint, compression=self.compression))

exporter/opentelemetry-exporter-otlp/src/opentelemetry/exporter/otlp/trace_exporter/__init__.py

@@ -52,6 +52,7 @@ class OTLPSpanExporter(
         endpoint: OpenTelemetry Collector receiver endpoint
         credentials: Credentials object for server authentication
         metadata: Metadata to send when exporting
+        compression: Compression algorithm to be used in channel
     """
 
     _result = SpanExportResult

exporter/opentelemetry-exporter-otlp/tests/test_otlp_trace_exporter.py

@@ -12,14 +12,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
+
 from collections import OrderedDict
 from concurrent.futures import ThreadPoolExecutor
 from unittest import TestCase
 from unittest.mock import Mock, PropertyMock, patch
 
 from google.protobuf.duration_pb2 import Duration
 from google.rpc.error_details_pb2 import RetryInfo
-from grpc import StatusCode, server
+from grpc import StatusCode, server, Compression
 
 from opentelemetry.exporter.otlp.trace_exporter import OTLPSpanExporter
 from opentelemetry.proto.collector.trace.v1.trace_service_pb2 import (
@@ -158,6 +160,19 @@ def setUp(self):
     def tearDown(self):
         self.server.stop(None)
 
+    def test_no_compression(self):
+        """Test default compression passed to constructor"""
+        exporter = OTLPSpanExporter()
+
+        self.assertEqual(exporter.compression, Compression.NoCompression)
+
+    def test_gzip_compression(self):
+        """Test the compression argument passed to constructor."""
+        compression = "gzip"
+        exporter = OTLPSpanExporter(compression=compression)
+
+        self.assertEqual(exporter.compression, Compression.Gzip)
+
     @patch("opentelemetry.exporter.otlp.exporter.expo")
     @patch("opentelemetry.exporter.otlp.exporter.sleep")
     def test_unavailable(self, mock_sleep, mock_expo):