feat: Allow filtering the http.target attribute

instrumentation/net_http/lib/opentelemetry/instrumentation/net/http/instrumentation.rb

@@ -26,7 +26,11 @@ class Instrumentation < OpenTelemetry::Instrumentation::Base
           #   or `Regexp` in this array, the instrumentation will not record a
           #   `kind = :client` representing the request and will not propagate
           #   context in the request.
-          option :untraced_hosts, default: [], validate: :array
+          # filter_target: a callable object that takes a path `String` and returns
+          #   a `String` to be used as the http.target attribute. The default is to
+          #   use the request path as-is.
+          option :untraced_hosts, default: [],  validate: :array
+          option :filter_target,  default: nil, validate: :callable
 
           private
 

instrumentation/net_http/lib/opentelemetry/instrumentation/net/http/patches/instrumentation.rb

@@ -23,7 +23,7 @@ def request(req, body = nil, &block)
               attributes = {
                 OpenTelemetry::SemanticConventions::Trace::HTTP_METHOD => req.method,
                 OpenTelemetry::SemanticConventions::Trace::HTTP_SCHEME => USE_SSL_TO_SCHEME[use_ssl?],
-                OpenTelemetry::SemanticConventions::Trace::HTTP_TARGET => req.path,
+                OpenTelemetry::SemanticConventions::Trace::HTTP_TARGET => filter_target(req.path),
                 OpenTelemetry::SemanticConventions::Trace::NET_PEER_NAME => @address,
                 OpenTelemetry::SemanticConventions::Trace::NET_PEER_PORT => @port
               }.merge!(OpenTelemetry::Common::HTTP::ClientContext.attributes)
@@ -85,6 +85,14 @@ def tracer
               Net::HTTP::Instrumentation.instance.tracer
             end
 
+            def filter_target(path)
+              if (filter = Net::HTTP::Instrumentation.instance.config[:filter_target])
+                filter.call(path)
+              else
+                path
+              end
+            end
+
             def untraced?
               return true if Net::HTTP::Instrumentation.instance.config[:untraced_hosts]&.any? do |host|
                 host.is_a?(Regexp) ? host.match?(@address) : host == @address

instrumentation/net_http/test/opentelemetry/instrumentation/net/http/instrumentation_test.rb

@@ -34,6 +34,31 @@
     OpenTelemetry.propagation = @orig_propagation
   end
 
+  describe '#filter_target' do
+    before do
+      stub_request(:get, 'http://example.com/path?token=broken').to_return(status: 200)
+      instrumentation.instance_variable_set(:@installed, false)
+      config = {
+        filter_target: proc { |path| URI(path).path }
+      }
+
+      instrumentation.install(config)
+    end
+
+    it 'reports the target without params' do
+      Net::HTTP.get(URI('http://example.com/path?token=broken'))
+
+      _(exporter.finished_spans.size).must_equal 1
+      _(span.attributes['http.target']).must_equal '/path'
+      _(span.attributes['net.peer.name']).must_equal 'example.com'
+      assert_requested(
+        :get,
+        'http://example.com/path?token=broken',
+        headers: { 'Traceparent' => "00-#{span.hex_trace_id}-#{span.hex_span_id}-01" }
+      )
+    end
+  end
+
   describe '#request' do
     it 'before request' do
       _(exporter.finished_spans.size).must_equal 0