fix: preserve existing flags when applying metrics patch

Ensure that enabling the manager_metrics_patch.yaml in config/default/kustomization.yaml does not overwrite existing arguments in config/manager/manager.yaml. The patch now appends the --metrics-bind-address argument without replacing other arguments.

More info: kubernetes-sigs#3934

docs/book/src/cronjob-tutorial/testdata/project/cmd/main.go

@@ -77,7 +77,7 @@ func main() {
 	var secureMetrics bool
 	var enableHTTP2 bool
 	flag.StringVar(&metricsAddr, "metrics-bind-address", "0", "The address the metric endpoint binds to. "+
-		"Use the port :8080. If not set, it will be '0 in order to disable the metrics server")
+		"Use the port :8080. If not set, it will be '0' in order to disable the metrics server")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+

docs/book/src/getting-started/testdata/project/cmd/main.go

@@ -58,7 +58,7 @@ func main() {
 	var secureMetrics bool
 	var enableHTTP2 bool
 	flag.StringVar(&metricsAddr, "metrics-bind-address", "0", "The address the metric endpoint binds to. "+
-		"Use the port :8080. If not set, it will be '0 in order to disable the metrics server")
+		"Use the port :8080. If not set, it will be '0' in order to disable the metrics server")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+

pkg/plugins/golang/v4/scaffolds/internal/templates/main.go

@@ -223,7 +223,7 @@ func main() {
 	var secureMetrics bool
 	var enableHTTP2 bool
 	flag.StringVar(&metricsAddr, "metrics-bind-address", "0", "The address the metric endpoint binds to. " +
-		"Use the port :8080. If not set, it will be '0 in order to disable the metrics server")
+		"Use the port :8080. If not set, it will be '0' in order to disable the metrics server")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. " +

testdata/project-v4-multigroup-with-deploy-image/cmd/main.go

@@ -83,7 +83,7 @@ func main() {
 	var secureMetrics bool
 	var enableHTTP2 bool
 	flag.StringVar(&metricsAddr, "metrics-bind-address", "0", "The address the metric endpoint binds to. "+
-		"Use the port :8080. If not set, it will be '0 in order to disable the metrics server")
+		"Use the port :8080. If not set, it will be '0' in order to disable the metrics server")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+

testdata/project-v4-multigroup/cmd/main.go

@@ -83,7 +83,7 @@ func main() {
 	var secureMetrics bool
 	var enableHTTP2 bool
 	flag.StringVar(&metricsAddr, "metrics-bind-address", "0", "The address the metric endpoint binds to. "+
-		"Use the port :8080. If not set, it will be '0 in order to disable the metrics server")
+		"Use the port :8080. If not set, it will be '0' in order to disable the metrics server")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+

testdata/project-v4-with-deploy-image/cmd/main.go

@@ -58,7 +58,7 @@ func main() {
 	var secureMetrics bool
 	var enableHTTP2 bool
 	flag.StringVar(&metricsAddr, "metrics-bind-address", "0", "The address the metric endpoint binds to. "+
-		"Use the port :8080. If not set, it will be '0 in order to disable the metrics server")
+		"Use the port :8080. If not set, it will be '0' in order to disable the metrics server")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+

testdata/project-v4-with-grafana/cmd/main.go

@@ -54,7 +54,7 @@ func main() {
 	var secureMetrics bool
 	var enableHTTP2 bool
 	flag.StringVar(&metricsAddr, "metrics-bind-address", "0", "The address the metric endpoint binds to. "+
-		"Use the port :8080. If not set, it will be '0 in order to disable the metrics server")
+		"Use the port :8080. If not set, it will be '0' in order to disable the metrics server")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+

testdata/project-v4/cmd/main.go

@@ -58,7 +58,7 @@ func main() {
 	var secureMetrics bool
 	var enableHTTP2 bool
 	flag.StringVar(&metricsAddr, "metrics-bind-address", "0", "The address the metric endpoint binds to. "+
-		"Use the port :8080. If not set, it will be '0 in order to disable the metrics server")
+		"Use the port :8080. If not set, it will be '0' in order to disable the metrics server")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+