doc/../metrics/*: Wrap main func in docs

Author: lilic

doc/user/metrics/README.md

@@ -12,28 +12,35 @@ By default, the metrics are served on `0.0.0.0:8383/metrics`. To modify the port
 
 ```go
     import(
-     "github.com/operator-framework/operator-sdk/pkg/metrics"
-	"sigs.k8s.io/controller-runtime/pkg/manager"
+        "github.com/operator-framework/operator-sdk/pkg/metrics"
+	    "sigs.k8s.io/controller-runtime/pkg/manager"
     )
 
-    // Change the below variables to serve metrics on different host or port.
-    var metricsHost = "0.0.0.0"
-    var metricsPort int32 = 8383
-
-    // Pass metrics address to controller-runtime manager
-	mgr, err := manager.New(cfg, manager.Options{
-		Namespace:          namespace,
-		MetricsBindAddress: fmt.Sprintf("%s:%d", metricsHost, metricsPort),
-	})
-	
-    ...
-
-	// Create Service object to expose the metrics port.
-	_, err = metrics.ExposeMetricsPort(ctx, metricsPort)
-	if err != nil {
-        // handle error
-		log.Info(err.Error())
-	}
+    func main() {
+
+        ...
+
+        // Change the below variables to serve metrics on different host or port.
+        var metricsHost = "0.0.0.0"
+        var metricsPort int32 = 8383
+
+        // Pass metrics address to controller-runtime manager
+        mgr, err := manager.New(cfg, manager.Options{
+            Namespace:          namespace,
+            MetricsBindAddress: fmt.Sprintf("%s:%d", metricsHost, metricsPort),
+        })
+        
+        ...
+
+        // Create Service object to expose the metrics port.
+        _, err = metrics.ExposeMetricsPort(ctx, metricsPort)
+        if err != nil {
+            // handle error
+            log.Info(err.Error())
+        }
+
+        ...
+    }
 ```
 
 Note: The above example is already present in `cmd/manager/main.go` in all the operators generated with operator-sdk.

doc/user/metrics/service-monitor.md

@@ -17,18 +17,25 @@ The `GenerateServiceMonitor` takes a `Service` object and generates a `ServiceMo
         v1 "k8s.io/api/core/v1"
         "github.com/operator-framework/operator-sdk/pkg/metrics"
     )
-    
-    // Populate bellow with Service(s) for which you want to create `ServiceMonitor` for.
-    services := []*v1.Service{}
-
-    // Create one `ServiceMonitor` per application per namespace.
-    // Change below value to name of the Namespace you want the `ServiceMonitor` to be created in.
-    ns := "default"
-    
-    // Pass the Service(s) to the helper function, which in turn returns the `ServiceMonitor` object.
-    serviceMonitors, err := metrics.CreateServiceMonitors(restConfig, ns, services)
-    if err != nil {
-        // handle error here
+
+    func main() {    
+        
+        ...
+
+        // Populate bellow with Service(s) for which you want to create `ServiceMonitor` for.
+        services := []*v1.Service{}
+
+        // Create one `ServiceMonitor` per application per namespace.
+        // Change below value to name of the Namespace you want the `ServiceMonitor` to be created in.
+        ns := "default"
+        
+        // Pass the Service(s) to the helper function, which in turn returns the `ServiceMonitor` object.
+        serviceMonitors, err := metrics.CreateServiceMonitors(restConfig, ns, services)
+        if err != nil {
+            // handle error here
+        }
+
+        ...
     }
 ```