feat(confighttp): add DisableKeepAlives to ServerConfig for all HTTP receivers

.chloggen/13783.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# 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. otlpreceiver)
+component: confighttp
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add `keep_alives_enabled` option to ServerConfig to control HTTP keep-alives for all HTTP servers
+
+# One or more tracking issues or pull requests related to the change
+issues: [13783]
+
+# (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:
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user, api]

config/confighttp/server.go

@@ -92,6 +92,10 @@ type ServerConfig struct {
 	// Middleware handlers are called in the order they appear in this list,
 	// with the first middleware becoming the outermost handler.
 	Middlewares []configmiddleware.Config `mapstructure:"middlewares,omitempty"`
+
+	// KeepAlivesEnabled controls whether HTTP keep-alives are enabled.
+	// By default, keep-alives are always enabled. Only very resource-constrained environments should disable them.
+	KeepAlivesEnabled bool `mapstructure:"keep_alives_enabled,omitempty"`
 }
 
 // NewDefaultServerConfig returns ServerConfig type object with default values.
@@ -102,6 +106,7 @@ func NewDefaultServerConfig() ServerConfig {
 		WriteTimeout:      30 * time.Second,
 		ReadHeaderTimeout: 1 * time.Minute,
 		IdleTimeout:       1 * time.Minute,
+		KeepAlivesEnabled: true,
 	}
 }
 
@@ -276,6 +281,9 @@ func (sc *ServerConfig) ToServer(ctx context.Context, host component.Host, setti
 		ErrorLog:          errorLog,
 	}
 
+	// Set keep-alives enabled/disabled
+	server.SetKeepAlivesEnabled(sc.KeepAlivesEnabled)
+
 	return server, err
 }
 

config/confighttp/server_test.go

@@ -957,6 +957,68 @@ func TestDefaultHTTPServerSettings(t *testing.T) {
 	assert.Equal(t, 30*time.Second, httpServerSettings.WriteTimeout)
 	assert.Equal(t, time.Duration(0), httpServerSettings.ReadTimeout)
 	assert.Equal(t, 1*time.Minute, httpServerSettings.ReadHeaderTimeout)
+	assert.True(t, httpServerSettings.KeepAlivesEnabled) // Default should be true (keep-alives enabled by default)
+}
+
+func TestHTTPServerKeepAlives(t *testing.T) {
+	tests := []struct {
+		name               string
+		keepAlivesEnabled  bool
+		expectedKeepAlives bool
+	}{
+		{
+			name:               "KeepAlives enabled",
+			keepAlivesEnabled:  true,
+			expectedKeepAlives: true,
+		},
+		{
+			name:               "KeepAlives disabled",
+			keepAlivesEnabled:  false,
+			expectedKeepAlives: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sc := &ServerConfig{
+				Endpoint:          "localhost:0",
+				KeepAlivesEnabled: tt.keepAlivesEnabled,
+			}
+
+			server, err := sc.ToServer(
+				context.Background(),
+				componenttest.NewNopHost(),
+				componenttest.NewNopTelemetrySettings(),
+				http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+					w.WriteHeader(http.StatusOK)
+				}))
+
+			require.NoError(t, err)
+			require.NotNil(t, server)
+
+			// Since http.Server.disableKeepAlives is a private field and difficult to test directly,
+			// we'll verify the configuration was set by testing the server behavior.
+			// The main verification is that ToServer() succeeds without error when DisableKeepAlives is set.
+
+			ln, err := sc.ToListener(context.Background())
+			require.NoError(t, err)
+
+			go func() {
+				_ = server.Serve(ln)
+			}()
+			defer func() {
+				_ = server.Close()
+			}()
+
+			resp, err := http.Get("http://" + ln.Addr().String())
+			require.NoError(t, err)
+			require.NotNil(t, resp)
+			_ = resp.Body.Close()
+			assert.Equal(t, http.StatusOK, resp.StatusCode)
+
+			assert.Equal(t, tt.keepAlivesEnabled, sc.KeepAlivesEnabled)
+		})
+	}
 }
 
 func TestHTTPServerTelemetry_Tracing(t *testing.T) {
@@ -1058,6 +1120,7 @@ func TestServerUnmarshalYAMLComprehensiveConfig(t *testing.T) {
 	assert.Equal(t, 10*time.Second, serverConfig.ReadHeaderTimeout)
 	assert.Equal(t, 30*time.Second, serverConfig.WriteTimeout)
 	assert.Equal(t, 120*time.Second, serverConfig.IdleTimeout)
+	assert.True(t, serverConfig.KeepAlivesEnabled) // Should be true as configured in config.yaml
 	assert.Equal(t, int64(33554432), serverConfig.MaxRequestBodySize)
 	assert.True(t, serverConfig.IncludeMetadata)
 

config/confighttp/testdata/config.yaml

@@ -90,6 +90,9 @@ server:
   write_timeout: 30s
   idle_timeout: 120s
 
+  # HTTP keep-alives configuration
+  keep_alives_enabled: true
+
   # Maximum request size
   max_request_body_size: 33554432  # 32MB
 

internal/e2e/confighttp_test.go

@@ -33,6 +33,7 @@ func TestConfmapMarshalConfigHTTP(t *testing.T) {
 	assert.Equal(t, map[string]any{
 		"cors":                nil,
 		"idle_timeout":        60 * time.Second,
+		"keep_alives_enabled": true,
 		"read_header_timeout": 60 * time.Second,
 		"response_headers":    map[string]any{},
 		"tls":                 nil,

receiver/otlpreceiver/config_test.go

@@ -140,7 +140,8 @@ func TestUnmarshalConfig(t *testing.T) {
 							AllowedOrigins: []string{"https://*.test.com", "https://test.com"},
 							MaxAge:         7200,
 						}),
-						ResponseHeaders: map[string]configopaque.String{},
+						ResponseHeaders:   map[string]configopaque.String{},
+						KeepAlivesEnabled: true,
 					},
 					TracesURLPath:  "/traces",
 					MetricsURLPath: "/v2/metrics",
@@ -169,8 +170,9 @@ func TestUnmarshalConfigUnix(t *testing.T) {
 				}),
 				HTTP: configoptional.Some(HTTPConfig{
 					ServerConfig: confighttp.ServerConfig{
-						Endpoint:        "/tmp/http_otlp.sock",
-						ResponseHeaders: map[string]configopaque.String{},
+						Endpoint:          "/tmp/http_otlp.sock",
+						ResponseHeaders:   map[string]configopaque.String{},
+						KeepAlivesEnabled: true,
 					},
 					TracesURLPath:  defaultTracesURLPath,
 					MetricsURLPath: defaultMetricsURLPath,