feat: add sending port as a resource attribute

.chloggen/apache-port-resource-attr.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: apachereceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: add port resource attribute
+
+# One or more tracking issues related to the change
+issues: [14791]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: 

receiver/apachereceiver/README.md

@@ -55,3 +55,13 @@ This is considered a breaking change for existing users of this receiver, and it
 This feature gate will eventually be enabled by default, and eventually the old implementation will be removed. It aims
 to give users time to migrate to the new implementation. The target release for this featuregate to be enabled by default
 is 0.66.0.
+
+**ALPHA**: `receiver.apache.emitPortAsResourceAttribute`
+
+The feature gate `receiver.apache.emitPortAsResourceAttribute` once enabled starts emitting the metrics with a resource attribute `apache.server.port`.
+
+This is considered a breaking change for existing users of this receiver, and it is recommended to migrate to the new implementation when possible. Any new users planning to adopt this receiver should enable this feature gate to avoid having to migrate any visualisations or alerts.
+
+This feature gate will eventually be enabled by default, and eventually the old implementation will be removed. It aims
+to give users time to migrate to the new implementation. The target release for this featuregate to be enabled by default
+is 0.66.0.

receiver/apachereceiver/config.go

@@ -28,6 +28,7 @@ type Config struct {
 	scraperhelper.ScraperControllerSettings `mapstructure:",squash"`
 	confighttp.HTTPClientSettings           `mapstructure:",squash"`
 	serverName                              string
+	port                                    string
 	Metrics                                 metadata.MetricsSettings `mapstructure:"metrics"`
 }
 
@@ -37,6 +38,9 @@ var (
 	defaultPort     = "8080"
 	defaultPath     = "server-status"
 	defaultEndpoint = fmt.Sprintf("%s%s:%s/%s?auto", defaultProtocol, defaultHost, defaultPort, defaultPath)
+
+	httpDefaultPort  = "80"
+	httpsDefaultPort = "443"
 )
 
 func (cfg *Config) Validate() error {
@@ -55,5 +59,16 @@ func (cfg *Config) Validate() error {
 	}
 
 	cfg.serverName = u.Hostname()
+	cfg.port = u.Port()
+
+	if cfg.port == "" {
+		if u.Scheme == "https" {
+			cfg.port = httpsDefaultPort
+		} else if u.Scheme == "http" {
+			cfg.port = httpDefaultPort
+		}
+		// else: unknown scheme, leave port as empty string
+	}
+
 	return nil
 }

receiver/apachereceiver/config_test.go

@@ -107,3 +107,52 @@ func TestLoadConfig(t *testing.T) {
 
 	require.Equal(t, expected, cfg)
 }
+
+func TestPortValidate(t *testing.T) {
+	testCases := []struct {
+		desc         string
+		endpoint     string
+		expectedPort string
+	}{
+		{
+			desc:         "http with specified port",
+			endpoint:     "http://localhost:8080/server-status?auto",
+			expectedPort: "8080",
+		},
+		{
+			desc:         "http without specified port",
+			endpoint:     "http://localhost/server-status?auto",
+			expectedPort: "80",
+		},
+		{
+			desc:         "https with specified port",
+			endpoint:     "https://localhost:8080/server-status?auto",
+			expectedPort: "8080",
+		},
+		{
+			desc:         "https without specified port",
+			endpoint:     "https://localhost/server-status?auto",
+			expectedPort: "443",
+		},
+		{
+			desc:         "unknown protocol with specified port",
+			endpoint:     "abc://localhost:8080/server-status?auto",
+			expectedPort: "8080",
+		},
+		{
+			desc:         "port unresolvable",
+			endpoint:     "abc://localhost/server-status?auto",
+			expectedPort: "",
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			cfg := NewFactory().CreateDefaultConfig().(*Config)
+			cfg.Endpoint = tc.endpoint
+			err := cfg.Validate()
+
+			require.NoError(t, err)
+			require.Equal(t, tc.expectedPort, cfg.port)
+		})
+	}
+}

receiver/apachereceiver/documentation.md

@@ -35,6 +35,7 @@ metrics:
 | Name | Description | Type |
 | ---- | ----------- | ---- |
 | apache.server.name | The name of the Apache HTTP server. | Str |
+| apache.server.port | The port of the Apache HTTP server. | Str |
 
 ## Metric attributes
 

receiver/apachereceiver/metadata.yaml

@@ -4,6 +4,9 @@ resource_attributes:
     apache.server.name:
       description: The name of the Apache HTTP server.
       type: string
+    apache.server.port:
+      description: The port of the Apache HTTP server.
+      type: string
 
 attributes:
   workers_state:

receiver/apachereceiver/scraper.go

@@ -37,6 +37,8 @@ import (
 const (
 	readmeURL                         = "https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/receiver/apachereceiver/README.md"
 	EmitServerNameAsResourceAttribute = "receiver.apache.emitServerNameAsResourceAttribute"
+	EmitPortAsResourceAttribute       = "receiver.apache.emitPortAsResourceAttribute"
+	featureGateWarning                = "Feature gate %s is not enabled. Please see the README.md file of apache receiver for more information."
 )
 
 var (
@@ -46,10 +48,16 @@ var (
 		Description: "When enabled, the name of the server will be sent as an apache.server.name resource attribute " +
 			"instead of a metric-level server_name attribute.",
 	}
+	emitPortAsResourceAttribute = featuregate.Gate{
+		ID:          EmitPortAsResourceAttribute,
+		Enabled:     false,
+		Description: "When enabled, the port of the server will be sent as an apache.server.name resource attribute.",
+	}
 )
 
 func init() {
 	featuregate.GetRegistry().MustRegister(emitServerNameAsResourceAttribute)
+	featuregate.GetRegistry().MustRegister(emitPortAsResourceAttribute)
 }
 
 type apacheScraper struct {
@@ -60,6 +68,7 @@ type apacheScraper struct {
 
 	// Feature gates regarding resource attributes
 	emitMetricsWithServerNameAsResourceAttribute bool
+	emitMetricsWithPortAsResourceAttribute       bool
 }
 
 func newApacheScraper(
@@ -71,6 +80,7 @@ func newApacheScraper(
 		cfg:      cfg,
 		mb:       metadata.NewMetricsBuilder(cfg.Metrics, settings.BuildInfo),
 		emitMetricsWithServerNameAsResourceAttribute: featuregate.GetRegistry().IsEnabled(EmitServerNameAsResourceAttribute),
+		emitMetricsWithPortAsResourceAttribute:       featuregate.GetRegistry().IsEnabled(EmitPortAsResourceAttribute),
 	}
 
 	if !a.emitMetricsWithServerNameAsResourceAttribute {
@@ -79,6 +89,12 @@ func newApacheScraper(
 		)
 	}
 
+	if !a.emitMetricsWithPortAsResourceAttribute {
+		settings.Logger.Warn(
+			fmt.Sprintf("Feature gate %s is not enabled. Please see the README for more information: %s", EmitPortAsResourceAttribute, readmeURL),
+		)
+	}
+
 	return a
 }
 
@@ -111,6 +127,10 @@ func (r *apacheScraper) scrape(context.Context) (pmetric.Metrics, error) {
 		err = r.scrapeWithServerNameAttr(stats)
 	}
 
+	if r.emitMetricsWithPortAsResourceAttribute {
+		emitWith = append(emitWith, metadata.WithApacheServerPort(r.cfg.port))
+	}
+
 	return r.mb.Emit(emitWith...), err
 }
 

receiver/apachereceiver/scraper_test.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"net/url"
 	"path/filepath"
 	"testing"
 
@@ -41,8 +42,7 @@ func TestScraper(t *testing.T) {
 	require.NoError(t, cfg.Validate())
 
 	// Let this test check if it works with the feature enabled and the integration test will test the feature disabled.
-	err := featuregate.GetRegistry().Apply(map[string]bool{EmitServerNameAsResourceAttribute: true})
-
+	err := featuregate.GetRegistry().Apply(map[string]bool{EmitServerNameAsResourceAttribute: true, EmitPortAsResourceAttribute: true})
 	require.NoError(t, err)
 
 	scraper := newApacheScraper(componenttest.NewNopReceiverCreateSettings(), cfg)
@@ -56,7 +56,12 @@ func TestScraper(t *testing.T) {
 	expectedFile := filepath.Join("testdata", "scraper", "expected.json")
 	expectedMetrics, err := golden.ReadMetrics(expectedFile)
 	require.NoError(t, err)
+	url, err := url.Parse(apacheMock.URL)
+	require.NoError(t, err)
+	expectedMetrics.ResourceMetrics().At(0).Resource().Attributes().Remove("apache.server.port")
+	expectedMetrics.ResourceMetrics().At(0).Resource().Attributes().PutStr("apache.server.port", url.Port())
 
+	// The port is random, so we shouldn't check if this value matches.
 	require.NoError(t, scrapertest.CompareMetrics(expectedMetrics, actualMetrics))
 }
 

receiver/apachereceiver/testdata/scraper/expected.json

@@ -8,7 +8,13 @@
              "value": {
                 "stringValue": "127.0.0.1"
              }
-          }
+          },
+          {
+            "key": "apache.server.port",
+            "value": {
+               "stringValue": "8080"
+            }
+         }
         ]
       },
       "scopeMetrics": [