Azure Classroom Series – 03/Jun/2020

Improving the template

• In the last series we had created the following template

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
    "contentVersion": "0.0.0.1",
    "resources": [
        {
            "name": "armvnet",
            "type": "Microsoft.Network/virtualNetworks",
            "apiVersion": "2020-04-01",
            "location": "eastus",
            "properties": {
                "addressSpace": {
                    "addressPrefixes": [
                        "192.168.0.0/16"
                    ]
                },
                "subnets": [
                    {
                        "name": "subnet1",
                        "properties": {
                            "addressPrefix": "192.168.0.0/24"
                        }
                    },
                    {
                        "name": "subnet2",
                        "properties": {
                            "addressPrefix": "192.168.1.0/24"
                        }
                    },
                    {
                        "name": "subnet3",
                        "properties": {
                            "addressPrefix": "192.168.2.0/24"
                        }
                    },
                    {
                        "name": "subnet4",
                        "properties": {
                            "addressPrefix": "192.168.3.0/24"
                        }
                    },

                    {
                        "name": "subnet5",
                        "properties": {
                            "addressPrefix": "192.168.4.0/24"
                        }
                    },
                    {
                        "name": "subnet6",
                        "properties": {
                            "addressPrefix": "192.168.5.0/24"
                        }
                    }

                ]
            }
        },
        {
            "name": "qtstoragedemoarm",
            "type": "Microsoft.Storage/storageAccounts",
            "apiVersion": "2019-06-01",
            "tags": {
                "displayName": "qtstoragedemoarm"
            },
            "location": "eastus",
            "kind": "StorageV2",
            "sku": {
                "name": "Standard_RAGRS",
                "tier": "Standard"
            },
            "properties": {
                "accessTier": "Hot"
            }
        }
    ]

}

• To make this script more generic, we need to parametrize, In arm template we use parameters to take input from users. Refer Here for docs

"parameters": {
  "<parameter-name>" : {
    "type" : "<type-of-parameter-value>",
    "defaultValue": "<default-value-of-parameter>",
    "allowedValues": [ "<array-of-allowed-values>" ],
    "minValue": <minimum-value-for-int>,
    "maxValue": <maximum-value-for-int>,
    "minLength": <minimum-length-for-string-or-array>,
    "maxLength": <maximum-length-for-string-or-array-parameters>,
    "metadata": {
      "description": "<description-of-the parameter>"
    }
  }
}

• To use the parameter the syntax is "[parameters(‘<parameter-name>’)]"
• Adding parametres will change the template as shown below

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
    "contentVersion": "0.0.0.2",
    "parameters": {
        "vnetname": {
            "type": "string",
            "metadata": {
                "description": "This is virtual network name"
            },
            "defaultValue": "ntier"

        },
        "subnetnames": {
            "type": "array",
            "metadata": {
                "description": "Names of the subnets"
            },
            "defaultValue": [
                "web",
                "app",
                "db",
                "management"
            ]
        },
        "vnetaddress": {
            "type": "string",
            "metadata": {
                "description": "description"
            },
            "defaultValue": "192.168.0.0/16",
            "allowedValues": [
                "192.168.0.0/16",
                "10.0.0.0/16",
                "172.16.0.0/16"
            ]
        },
        "subnetcidranges": {
            "type": "array",
            "metadata": {
                "description": "subnet ranges"
            },
            "defaultValue": [
                "192.168.0.0/24",
                "192.168.1.0/24",
                "192.168.2.0/24",
                "192.168.3.0/24"
            ]
        },
        "storageaccountname": {
            "type": "string",
            "metadata": {
                "description": "storage account name"
            },
            "defaultValue": "qtstoragedemoarm.com"
        }

    },
    "resources": [
        {
            "name": "[parameters('vnetname')]",
            "type": "Microsoft.Network/virtualNetworks",
            "apiVersion": "2020-04-01",
            "location": "eastus",
            "properties": {
                "addressSpace": {
                    "addressPrefixes": [
                        "[parameters('vnetaddress')]"
                    ]
                },
                "subnets": [
                    {
                        "name": "[parameters('subnetnames')[0]]",
                        "properties": {
                            "addressPrefix": "[parameters('subnetcidranges')[0]]"
                        }
                    },
                    {
                        "name": "[parameters('subnetnames')[1]]",
                        "properties": {
                            "addressPrefix": "[parameters('subnetcidranges')[1]]"
                        }
                    },
                    {
                        "name": "[parameters('subnetnames')[2]]",
                        "properties": {
                            "addressPrefix": "[parameters('subnetcidranges')[2]]"
                        }
                    },
                    {
                        "name": "[parameters('subnetnames')[3]]",
                        "properties": {
                            "addressPrefix": "[parameters('subnetcidranges')[3]]"
                        }
                    }
                ]
            }
        },
        {
            "name": "[parameters('storageaccountname')]",
            "type": "Microsoft.Storage/storageAccounts",
            "apiVersion": "2019-06-01",
            "tags": {
                "displayName": "qtstoragedemoarm"
            },
            "location": "eastus",
            "kind": "StorageV2",
            "sku": {
                "name": "Standard_RAGRS",
                "tier": "Standard"
            },
            "properties": {
                "accessTier": "Hot"
            }
        }
    ]

}

• Deploy this template using portal (can be done from cli & powershell)
• To make the script more effective lets look at Copy
• To adopt we need to understand child resource Refer here

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
    "contentVersion": "0.0.0.2",
    "parameters": {
        "vnetname": {
            "type": "string",
            "metadata": {
                "description": "This is virtual network name"
            },
            "defaultValue": "ntier"

        },
        "subnetcount": {
            "type": "int",
            "defaultValue": 4
        },
        "subnetnames": {
            "type": "array",
            "metadata": {
                "description": "Names of the subnets"
            },
            "defaultValue": [
                "ntier/web",
                "ntier/app",
                "ntier/db",
                "ntier/management"
            ]
        },
        "vnetaddress": {
            "type": "string",
            "metadata": {
                "description": "description"
            },
            "defaultValue": "192.168.0.0/16",
            "allowedValues": [
                "192.168.0.0/16",
                "10.0.0.0/16",
                "172.16.0.0/16"
            ]
        },
        "subnetcidranges": {
            "type": "array",
            "metadata": {
                "description": "subnet ranges"
            },
            "defaultValue": [
                "192.168.0.0/24",
                "192.168.1.0/24",
                "192.168.2.0/24",
                "192.168.3.0/24"
            ]
        },
        "storageaccountname": {
            "type": "string",
            "metadata": {
                "description": "storage account name"
            },
            "defaultValue": "qtstoragedemoarm.com"
        }

    },
    "resources": [
        {
            "name": "[parameters('vnetname')]",
            "type": "Microsoft.Network/virtualNetworks",
            "apiVersion": "2020-04-01",
            "location": "eastus",
            "properties": {
                "addressSpace": {
                    "addressPrefixes": [
                        "[parameters('vnetaddress')]"
                    ]
                }
            }
        },
        {
            "name": "[parameters('subnetnames')[copyIndex()]]",
            "type": "Microsoft.Network/virtualNetworks/subnets",
            "apiVersion": "2020-04-01",
            "properties": {
                "addressPrefix": "[parameters('subnetcidranges')[copyIndex()]]"
            },
            "copy": {
                "name": "subnetcopy",
                "count": "[parameters('subnetcount')]",
                "mode": "serial"
            },
            "dependsOn": [
                "[parameters('vnetname')]"
            ]
        },
        {
            "name": "[parameters('storageaccountname')]",
            "type": "Microsoft.Storage/storageAccounts",
            "apiVersion": "2019-06-01",
            "tags": {
                "displayName": "qtstoragedemoarm"
            },
            "location": "eastus",
            "kind": "StorageV2",
            "sku": {
                "name": "Standard_RAGRS",
                "tier": "Standard"
            },
            "properties": {
                "accessTier": "Hot"
            }
        }
    ]

}

• In this script i have used depends on function

• Next steps: Lets look at template funtions,varaibles, outputs and improvise the arm template

• Exercise:

  1. Add network security group to the template
  2. Add public ip address to the template
  3. add network interface to the template