update README.md

README.md

@@ -1,11 +1,33 @@
 # swiro
 
+swiro is a switching route tool for AWS to realize VIP (Virtual IP) with Routing-Based High Availability pattern.
+It is possible to perform failover (switching of the connection destination) of the EC2 redundant across the subnet (AZ).
 
 
-## Description
-
 ## Usage
 
+* Switching routes
+
+```
+$ swiro switch rtb-xxxxxx 10.0.0.1 -I i-xxxxxx
+```
+
+
+## Example
+
+```
+$ swiro switch rtb-xxxxxx 10.0.0.1 -I i-xxxxxx
+Switch the route below setting:
+============================================
+Route Table: route_table_name (rtb-xxxxxx)
+Virtual IP:  10.0.0.1 -------- Src:  src_instance_name (i-xxxxxx)
+                      \\
+                       ======> Dest: dest_instance_name (i-xxxxxx)
+============================================
+Are you sure? (y/n) [y]: y
+Success!!
+```
+
 ## Install
 
 To install, use `go get`:

aws/route_table.go

@@ -62,6 +62,9 @@ func (t *RouteTable) ReplaceRoute(vip, instance string) error {
 	if err = t.cli.replaceRoute(ctx, routeTableId, destinationCidrBlock, instanceId); err != nil {
 		return err
 	}
+
+	// TODO: check whether the route has actually replaced
+
 	return nil
 }
 

command/switch.go

@@ -56,6 +56,7 @@ Are you sure?`
 	if err != nil {
 		return err
 	}
+	fmt.Fprintln(os.Stdout, "Success!!")
 
 	return nil
 }