feat: Exporter should use gzip compression by default (#934)

* Exporter should use gzip compression by default

* Fix spec

* Fix tests

Co-authored-by: Ariel Valentin <[email protected]>
Co-authored-by: Francis Bogsanyi <[email protected]>

Author: 3 people

exporter/otlp/lib/opentelemetry/exporter/otlp/exporter.rb

@@ -48,7 +48,7 @@ def initialize(endpoint: config_opt('OTEL_EXPORTER_OTLP_TRACES_ENDPOINT', 'OTEL_
                        certificate_file: config_opt('OTEL_EXPORTER_OTLP_TRACES_CERTIFICATE', 'OTEL_EXPORTER_OTLP_CERTIFICATE'),
                        ssl_verify_mode: Exporter.ssl_verify_mode,
                        headers: config_opt('OTEL_EXPORTER_OTLP_TRACES_HEADERS', 'OTEL_EXPORTER_OTLP_HEADERS', default: {}),
-                       compression: config_opt('OTEL_EXPORTER_OTLP_TRACES_COMPRESSION', 'OTEL_EXPORTER_OTLP_COMPRESSION'),
+                       compression: config_opt('OTEL_EXPORTER_OTLP_TRACES_COMPRESSION', 'OTEL_EXPORTER_OTLP_COMPRESSION', default: 'gzip'),
                        timeout: config_opt('OTEL_EXPORTER_OTLP_TRACES_TIMEOUT', 'OTEL_EXPORTER_OTLP_TIMEOUT', default: 10),
                        metrics_reporter: nil)
           raise ArgumentError, "invalid url for OTLP::Exporter #{endpoint}" if invalid_url?(endpoint)

exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb

@@ -17,7 +17,7 @@
       _(exp.instance_variable_get(:@headers)).must_be_empty
       _(exp.instance_variable_get(:@timeout)).must_equal 10.0
       _(exp.instance_variable_get(:@path)).must_equal '/v1/traces'
-      _(exp.instance_variable_get(:@compression)).must_be_nil
+      _(exp.instance_variable_get(:@compression)).must_equal 'gzip'
       http = exp.instance_variable_get(:@http)
       _(http.ca_file).must_be_nil
       _(http.use_ssl?).must_equal true
@@ -414,7 +414,8 @@
     it 'batches per resource' do
       etsr = nil
       stub_post = stub_request(:post, 'https://localhost:4318/v1/traces').to_return do |request|
-        etsr = Opentelemetry::Proto::Collector::Trace::V1::ExportTraceServiceRequest.decode(request.body)
+        proto = Zlib.gunzip(request.body)
+        etsr = Opentelemetry::Proto::Collector::Trace::V1::ExportTraceServiceRequest.decode(proto)
         { status: 200 }
       end
 
@@ -593,7 +594,7 @@
       )
 
       assert_requested(:post, 'https://localhost:4318/v1/traces') do |req|
-        req.body == encoded_etsr
+        req.body == Zlib.gzip(encoded_etsr)
       end
     end
   end