caddyfile: add observe_catchall_hosts option (#7434)

* caddyfile: add `observe_catchall_hosts` option

Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>

* correct JSON field name and doc comment

Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>

---------

Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>

caddyconfig/httpcaddyfile/options.go

@@ -472,6 +472,8 @@ func unmarshalCaddyfileMetricsOptions(d *caddyfile.Dispenser) (any, error) {
 		switch d.Val() {
 		case "per_host":
 			metrics.PerHost = true
+		case "observe_catchall_hosts":
+			metrics.ObserveCatchallHosts = true
 		default:
 			return nil, d.Errf("unrecognized servers option '%s'", d.Val())
 		}

modules/caddyhttp/metrics.go

@@ -25,7 +25,7 @@ import (
 //			"http": {
 //				"metrics": {
 //					"per_host": true,
-//					"allow_catch_all_hosts": false
+//					"observe_catchall_hosts": false
 //				},
 //				"servers": {
 //					"srv0": {
@@ -65,7 +65,7 @@ type Metrics struct {
 	//
 	// Set to true to allow all hosts to get individual metrics (NOT RECOMMENDED
 	// for production environments exposed to the internet).
-	AllowCatchAllHosts bool `json:"allow_catch_all_hosts,omitempty"`
+	ObserveCatchallHosts bool `json:"observe_catchall_hosts,omitempty"`
 
 	init           sync.Once
 	httpMetrics    *httpMetrics
@@ -200,7 +200,7 @@ func (m *Metrics) shouldAllowHostMetrics(host string, isHTTPS bool) bool {
 	}
 
 	// For catch-all requests (not in allowed hosts)
-	allowCatchAll := m.AllowCatchAllHosts || (isHTTPS && m.hasHTTPSServer)
+	allowCatchAll := m.ObserveCatchallHosts || (isHTTPS && m.hasHTTPSServer)
 	return allowCatchAll
 }
 

modules/caddyhttp/metrics_test.go

@@ -207,11 +207,11 @@ func TestMetricsInstrumentedHandler(t *testing.T) {
 func TestMetricsInstrumentedHandlerPerHost(t *testing.T) {
 	ctx, _ := caddy.NewContext(caddy.Context{Context: context.Background()})
 	metrics := &Metrics{
-		PerHost:            true,
-		AllowCatchAllHosts: true, // Allow all hosts for testing
-		init:               sync.Once{},
-		httpMetrics:        &httpMetrics{},
-		allowedHosts:       make(map[string]struct{}),
+		PerHost:              true,
+		ObserveCatchallHosts: true, // Allow all hosts for testing
+		init:                 sync.Once{},
+		httpMetrics:          &httpMetrics{},
+		allowedHosts:         make(map[string]struct{}),
 	}
 	handlerErr := errors.New("oh noes")
 	response := []byte("hello world!")
@@ -387,11 +387,11 @@ func TestMetricsCardinalityProtection(t *testing.T) {
 
 	// Test 1: Without AllowCatchAllHosts, arbitrary hosts should be mapped to "_other"
 	metrics := &Metrics{
-		PerHost:            true,
-		AllowCatchAllHosts: false, // Default - should map unknown hosts to "_other"
-		init:               sync.Once{},
-		httpMetrics:        &httpMetrics{},
-		allowedHosts:       make(map[string]struct{}),
+		PerHost:              true,
+		ObserveCatchallHosts: false, // Default - should map unknown hosts to "_other"
+		init:                 sync.Once{},
+		httpMetrics:          &httpMetrics{},
+		allowedHosts:         make(map[string]struct{}),
 	}
 
 	// Add one allowed host
@@ -444,12 +444,12 @@ func TestMetricsHTTPSCatchAll(t *testing.T) {
 
 	// Test that HTTPS requests allow catch-all even when AllowCatchAllHosts is false
 	metrics := &Metrics{
-		PerHost:            true,
-		AllowCatchAllHosts: false,
-		hasHTTPSServer:     true, // Simulate having HTTPS servers
-		init:               sync.Once{},
-		httpMetrics:        &httpMetrics{},
-		allowedHosts:       make(map[string]struct{}), // Empty - no explicitly allowed hosts
+		PerHost:              true,
+		ObserveCatchallHosts: false,
+		hasHTTPSServer:       true, // Simulate having HTTPS servers
+		init:                 sync.Once{},
+		httpMetrics:          &httpMetrics{},
+		allowedHosts:         make(map[string]struct{}), // Empty - no explicitly allowed hosts
 	}
 
 	mh := middlewareHandlerFunc(func(w http.ResponseWriter, r *http.Request, h Handler) error {