fix: Add net.peer.name to ethon (#1004)

The ethon instrumentation did not include the `net.peer.name` attribute like other HTTP instrumentations and was not ported from ddtrace-rb: <https://github.com/DataDog/dd-trace-rb/blob/master/lib/datadog/tracing/contrib/ethon/easy_patch.rb#L159>

This attribute is important to GitHub because we base the `peer.service` extracting the subdomain and host information from `net.peer.name`.

In order to avoid parsing the URL multiple times, I inlined the common gem `cleanse_url` function and plan to open a separate PR adding a feature to support returing URI objects instead of Strings.

Author: arielvalentin

instrumentation/ethon/Appraisals

@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-appraise 'ethon-0.12' do
-  gem 'ethon', '~> 0.12.0'
+appraise 'ethon-0.16' do
+  gem 'ethon', '~> 0.16.0'
 end
 
-appraise 'ethon-0.11' do
-  gem 'ethon', '~> 0.11.0'
+appraise 'ethon-latest' do
+  gem 'ethon'
 end

instrumentation/ethon/lib/opentelemetry/instrumentation/ethon/patches/easy.rb

@@ -87,8 +87,11 @@ def span_creation_attributes(method)
               'http.method' => method
             }
 
-            http_url = OpenTelemetry::Common::Utilities.cleanse_url(url)
-            instrumentation_attrs['http.url'] = http_url if http_url
+            uri = _otel_cleanse_uri(url)
+            if uri
+              instrumentation_attrs['http.url'] = uri.to_s
+              instrumentation_attrs['net.peer.name'] = uri.host if uri.host
+            end
 
             config = Ethon::Instrumentation.instance.config
             instrumentation_attrs['peer.service'] = config[:peer_service] if config[:peer_service]
@@ -97,6 +100,20 @@ def span_creation_attributes(method)
             )
           end
 
+          # Returns a URL string with userinfo removed.
+          #
+          # @param [String] url The URL string to cleanse.
+          #
+          # @return [String] the cleansed URL.
+          def _otel_cleanse_uri(url)
+            cleansed_url = URI.parse(url)
+            cleansed_url.password = nil
+            cleansed_url.user = nil
+            cleansed_url
+          rescue URI::Error
+            nil
+          end
+
           def tracer
             Ethon::Instrumentation.instance.tracer
           end

instrumentation/ethon/test/opentelemetry/instrumentation/ethon/instrumentation_test.rb

@@ -71,6 +71,7 @@
               _(span.attributes['http.method']).must_equal 'N/A'
               _(span.attributes['http.status_code']).must_be_nil
               _(span.attributes['http.url']).must_equal 'http://example.com/test'
+              _(span.attributes['net.peer.name']).must_equal 'example.com'
             end
           end
         end
@@ -275,8 +276,10 @@ def stub_response(options)
             multi.perform
 
             _(exporter.finished_spans.size).must_equal 2
-            _(exporter.finished_spans[0].attributes['http.url']).must_equal nil
+            _(exporter.finished_spans[0].attributes['http.url']).must_be_nil
+            _(exporter.finished_spans[0].attributes['net.peer.name']).must_be_nil
             _(exporter.finished_spans[1].attributes['http.url']).must_equal 'test'
+            _(exporter.finished_spans[1].attributes['net.peer.name']).must_be_nil
           end
         end
       end