application_gateway.md in fog-azure-rm-0.2.0

- old
+ new

@@ -13,17 +13,24 @@
 
 Next, create a connection to the Application Gateway Service:
 
 ```ruby
     azure_application_gateway_service = Fog::ApplicationGateway::AzureRM.new(
-        tenant_id: '<Tenantid>',                  # Tenant id of Azure Active Directory Application
-        client_id:    '<Clientid>',               # Client id of Azure Active Directory Application
-        client_secret: '<ClientSecret>',          # Client Secret of Azure Active Directory Application
-        subscription_id: '<Subscriptionid>'       # Subscription id of an Azure Account
+    tenant_id: '<Tenantid>',                                                              # Tenant id of Azure Active Directory Application
+        client_id:    '<Clientid>',                                                       # Client id of Azure Active Directory Application
+        client_secret: '<ClientSecret>',                                                  # Client Secret of Azure Active Directory Application
+        subscription_id: '<Subscriptionid>',                                              # Subscription id of an Azure Account
+        :environment => '<AzureCloud/AzureChinaCloud/AzureUSGovernment/AzureGermanCloud>' # Azure cloud environment. Default is AzureCloud.
 )
 ```
 
+## Check Application Gateway Existence
+
+```ruby
+azure_application_gateway_service.gateways.check_application_gateway_exists(<Resource Group name>, <Gateway Name>)
+```
+
 ## Create Application Gateway
 
 Create a new Application Gateway.
 
 ```ruby
@@ -102,9 +109,36 @@
             ]
 
 
     )
 ```
+
+There can be two ways of giving `frontend_ip_configurations` while creating application gateway
+
+1. When giving public ip, then we need to provide `public_ip_address_id` as follows
+
+`frontend_ip_configurations:
+    [
+        {
+            name: 'frontendIpConfig',
+            private_ip_allocation_method: 'Dynamic',
+            public_ip_address_id: '/subscriptions/<Subscription_id>/resourcegroups/<Resource Group name>/providers/Microsoft.Network/publicIPAddresses/<Public IP Address Name>',
+            private_ip_address: '10.0.1.5'
+        }
+]`
+
+2. When giving subnet id, then we need to provide `subnet_id` as follows
+
+`frontend_ip_configurations:
+    [
+        {
+            name: 'frontendIpConfig',
+            private_ip_allocation_method: 'Dynamic',
+            subnet_id: '<Subnet ID',
+            private_ip_address: '10.0.1.5'
+        }
+]`
+
 
 ## List Application Gateways
 
 List all application gateways in a resource group
 