Chore/refactor transport server listens (#6315)

* add makeTransportListener function

* add snap update

Author: Jim Ryan

internal/configs/version2/__snapshots__/templates_test.snap

@@ -5708,6 +5708,7 @@ match match_udp-upstream {
 server {
     listen 1234 ssl udp;
     listen [::]:1234 ssl udp;
+
     ssl_certificate cafe-secret.pem;
     ssl_certificate_key cafe-secret.pem;
 

internal/configs/version2/nginx-plus.transportserver.tmpl

@@ -39,8 +39,7 @@ server {
     listen {{ $s.UnixSocket }} proxy_protocol;
     set_real_ip_from unix:;
         {{- else }}
-    listen {{ $s.Port }}{{ if $ssl.Enabled }} ssl{{ end }}{{ if $s.UDP }} udp{{ end }};
-    {{if not $s.DisableIPV6}}listen [::]:{{ $s.Port }}{{ if $ssl.Enabled }} ssl{{ end }}{{ if $s.UDP }} udp{{ end }};{{end}}
+    {{ makeTransportListener $s | printf }}
         {{- end }}
 
         {{- if $ssl.Enabled }}

internal/configs/version2/nginx.transportserver.tmpl

@@ -23,8 +23,7 @@ server {
     listen {{ $s.UnixSocket }} proxy_protocol;
     set_real_ip_from unix:;
         {{- else }}
-    listen {{ $s.Port }}{{ if $ssl.Enabled }} ssl{{ end }}{{ if $s.UDP }} udp{{ end }};
-    {{if not $s.DisableIPV6}}listen [::]:{{ $s.Port }}{{ if $ssl.Enabled }} ssl{{ end }}{{ if $s.UDP }} udp{{ end }};{{end}}
+    {{ makeTransportListener $s | printf }}
         {{- end }}
 
         {{- if $ssl.Enabled }}

internal/configs/version2/template_helper.go

@@ -114,6 +114,28 @@ func buildListenDirective(port string, proxyProtocol bool, listenType listenerTy
 	return directive
 }
 
+func buildTransportListenDirective(listenType listenerType, port string, ssl *StreamSSL, udp bool) string {
+	base := "listen"
+	var directive string
+
+	if listenType == ipv6 {
+		directive = base + " [::]:" + port
+	} else {
+		directive = base + " " + port
+	}
+
+	if ssl.Enabled {
+		directive += " ssl"
+	}
+
+	if udp {
+		directive += " udp"
+	}
+
+	directive += ";\n"
+	return directive
+}
+
 func makeHTTPListener(s Server) string {
 	return makeListener(http, s)
 }
@@ -122,6 +144,20 @@ func makeHTTPSListener(s Server) string {
 	return makeListener(https, s)
 }
 
+func makeTransportListener(s StreamServer) string {
+	var directives string
+	port := strconv.Itoa(s.Port)
+
+	directives += buildTransportListenDirective(ipv4, port, s.SSL, s.UDP)
+
+	if !s.DisableIPV6 {
+		directives += spacing
+		directives += buildTransportListenDirective(ipv6, port, s.SSL, s.UDP)
+	}
+
+	return directives
+}
+
 func makeHeaderQueryValue(apiKey APIKey) string {
 	var parts []string
 
@@ -140,16 +176,17 @@ func makeHeaderQueryValue(apiKey APIKey) string {
 }
 
 var helperFunctions = template.FuncMap{
-	"headerListToCIMap":    headerListToCIMap,
-	"hasCIKey":             hasCIKey,
-	"contains":             strings.Contains,
-	"hasPrefix":            strings.HasPrefix,
-	"hasSuffix":            strings.HasSuffix,
-	"toLower":              strings.ToLower,
-	"toUpper":              strings.ToUpper,
-	"replaceAll":           strings.ReplaceAll,
-	"makeHTTPListener":     makeHTTPListener,
-	"makeHTTPSListener":    makeHTTPSListener,
-	"makeSecretPath":       commonhelpers.MakeSecretPath,
-	"makeHeaderQueryValue": makeHeaderQueryValue,
+	"headerListToCIMap":     headerListToCIMap,
+	"hasCIKey":              hasCIKey,
+	"contains":              strings.Contains,
+	"hasPrefix":             strings.HasPrefix,
+	"hasSuffix":             strings.HasSuffix,
+	"toLower":               strings.ToLower,
+	"toUpper":               strings.ToUpper,
+	"replaceAll":            strings.ReplaceAll,
+	"makeHTTPListener":      makeHTTPListener,
+	"makeHTTPSListener":     makeHTTPSListener,
+	"makeSecretPath":        commonhelpers.MakeSecretPath,
+	"makeHeaderQueryValue":  makeHeaderQueryValue,
+	"makeTransportListener": makeTransportListener,
 }

internal/configs/version2/template_helper_test.go

@@ -268,6 +268,72 @@ func TestMakeHTTPSListener(t *testing.T) {
 	}
 }
 
+func TestMakeTransportListener(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		server   StreamServer
+		expected string
+	}{
+		{server: StreamServer{
+			UDP: false,
+			SSL: &StreamSSL{
+				Enabled: false,
+			},
+			DisableIPV6: true,
+			Port:        5353,
+		}, expected: "listen 5353;\n"},
+		{server: StreamServer{
+			UDP: true,
+			SSL: &StreamSSL{
+				Enabled: false,
+			},
+			DisableIPV6: true,
+			Port:        5353,
+		}, expected: "listen 5353 udp;\n"},
+		{server: StreamServer{
+			UDP: true,
+			SSL: &StreamSSL{
+				Enabled: true,
+			},
+			DisableIPV6: true,
+			Port:        5353,
+		}, expected: "listen 5353 ssl udp;\n"},
+
+		{server: StreamServer{
+			UDP: false,
+			SSL: &StreamSSL{
+				Enabled: false,
+			},
+			DisableIPV6: false,
+			Port:        5353,
+		}, expected: "listen 5353;\n    listen [::]:5353;\n"},
+		{server: StreamServer{
+			UDP: true,
+			SSL: &StreamSSL{
+				Enabled: false,
+			},
+			DisableIPV6: false,
+			Port:        5353,
+		}, expected: "listen 5353 udp;\n    listen [::]:5353 udp;\n"},
+		{server: StreamServer{
+			UDP: true,
+			SSL: &StreamSSL{
+				Enabled: true,
+			},
+			DisableIPV6: false,
+			Port:        5353,
+		}, expected: "listen 5353 ssl udp;\n    listen [::]:5353 ssl udp;\n"},
+	}
+
+	for _, tc := range testCases {
+		got := makeTransportListener(tc.server)
+		if got != tc.expected {
+			t.Errorf("Function generated wrong config, got %q but expected %q.", got, tc.expected)
+		}
+	}
+}
+
 func newContainsTemplate(t *testing.T) *template.Template {
 	t.Helper()
 	tmpl, err := template.New("testTemplate").Funcs(helperFunctions).Parse(`{{contains .InputString .Substring}}`)