Set host or address as resource for Net::HTTP

Tracking external requests by host is more useful for understanding performance issues than tracking by HTTP method. By using the host we should have a smaller potential list than if we were tracking by URL/endpoint.

We don't always have a hostname, so lets use logic that exists for falling back to address.

lib/ddtrace/contrib/http/patcher.rb

@@ -110,12 +110,19 @@ def request(req, body = nil, &block) # :yield: +response+
 
               pin.tracer.trace(NAME) do |span|
                 begin
+
+                  if req.respond_to?(:uri) && req.uri
+                    host_address = req.uri.host
+                    host_port = req.uri.port.to_s
+                  else
+                    host_address = @address
+                    host_port = @port.to_s
+                  end
+
                   span.service = pin.service
                   span.span_type = Datadog::Ext::HTTP::TYPE
 
-                  span.resource = req.method
-                  # Using the method as a resource, as URL/path can trigger
-                  # a possibly infinite number of resources.
+                  span.resource = host_address
                   span.set_tag(Datadog::Ext::HTTP::URL, req.path)
                   span.set_tag(Datadog::Ext::HTTP::METHOD, req.method)
 
@@ -135,13 +142,8 @@ def request(req, body = nil, &block) # :yield: +response+
                   response = request_without_datadog(req, body, &block)
                 end
                 span.set_tag(Datadog::Ext::HTTP::STATUS_CODE, response.code)
-                if req.respond_to?(:uri) && req.uri
-                  span.set_tag(Datadog::Ext::NET::TARGET_HOST, req.uri.host)
-                  span.set_tag(Datadog::Ext::NET::TARGET_PORT, req.uri.port.to_s)
-                else
-                  span.set_tag(Datadog::Ext::NET::TARGET_HOST, @address)
-                  span.set_tag(Datadog::Ext::NET::TARGET_PORT, @port.to_s)
-                end
+                span.set_tag(Datadog::Ext::NET::TARGET_HOST, host_address)
+                span.set_tag(Datadog::Ext::NET::TARGET_PORT, host_port)
 
                 case response.code.to_i / 100
                 when 4

test/contrib/http/miniapp_test.rb

@@ -29,7 +29,7 @@ def check_span_page(span)
   def check_span_get(span, parent_id, trace_id)
     assert_equal('http.request', span.name)
     assert_equal('net/http', span.service)
-    assert_equal('GET', span.resource)
+    assert_equal(ELASTICSEARCH_HOST, span.resource)
     assert_equal('_cluster/health', span.get_tag('http.url'))
     assert_equal('GET', span.get_tag('http.method'))
     assert_equal('200', span.get_tag('http.status_code'))

test/contrib/http/request_test.rb

@@ -32,7 +32,7 @@ def test_get_request
     span = spans[0]
     assert_equal('http.request', span.name)
     assert_equal('net/http', span.service)
-    assert_equal('GET', span.resource)
+    assert_equal(ELASTICSEARCH_HOST, span.resource)
     assert_equal('_cluster/health', span.get_tag('http.url'))
     assert_equal('GET', span.get_tag('http.method'))
     assert_equal('200', span.get_tag('http.status_code'))
@@ -48,7 +48,7 @@ def test_post_request
     span = spans[0]
     assert_equal('http.request', span.name)
     assert_equal('net/http', span.service)
-    assert_equal('POST', span.resource)
+    assert_equal(ELASTICSEARCH_HOST, span.resource)
     assert_equal('/my/thing/42', span.get_tag('http.url'))
     assert_equal('POST', span.get_tag('http.method'))
     assert_equal('127.0.0.1', span.get_tag('out.host'))
@@ -64,7 +64,7 @@ def test_404
     span = spans[0]
     assert_equal('http.request', span.name)
     assert_equal('net/http', span.service)
-    assert_equal('GET', span.resource)
+    assert_equal(ELASTICSEARCH_HOST, span.resource)
     assert_equal('/admin.php?user=admin&passwd=123456', span.get_tag('http.url'))
     assert_equal('GET', span.get_tag('http.method'))
     assert_equal('404', span.get_tag('http.status_code'))
@@ -89,7 +89,7 @@ def test_pin_block_call
       span = spans[0]
       assert_equal('http.request', span.name)
       assert_equal('net/http', span.service)
-      assert_equal('GET', span.resource)
+      assert_equal(ELASTICSEARCH_HOST, span.resource)
       assert_equal('/_cluster/health', span.get_tag('http.url'))
       assert_equal('GET', span.get_tag('http.method'))
       assert_equal('200', span.get_tag('http.status_code'))