ARM template structure in Azure - Mini Project: Build & Apply

ARM template structure

📖 Scenario: You are working as a cloud engineer for a small company. Your manager wants you to create a simple Azure Resource Manager (ARM) template to deploy a storage account. This template will help automate the deployment process and ensure consistency.

🎯 Goal: Create a basic ARM template with the correct structure to deploy an Azure Storage Account resource.

📋 What You'll Learn

Create the ARM template skeleton with schema, contentVersion, parameters, variables, resources, and outputs sections.

Add a parameter called storageAccountName of type string.

Add a resource of type Microsoft.Storage/storageAccounts with API version 2022-09-01.

Set the storage account name using the storageAccountName parameter.

Set the location to eastus.

Set the SKU name to Standard_LRS.

Set the kind to StorageV2.

Output the storage account resource ID.

💡 Why This Matters

🌍 Real World

ARM templates are used to automate and standardize Azure resource deployments in real companies, saving time and reducing errors.

💼 Career

Understanding ARM template structure is essential for cloud engineers and DevOps professionals working with Azure infrastructure automation.

1

Create the ARM template skeleton

Create an ARM template JSON with the top-level keys: $schema, contentVersion, parameters, variables, resources, and outputs. Set $schema to "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#" and contentVersion to "1.0.0.0". Leave parameters, variables, resources, and outputs as empty objects or arrays as appropriate.

Azure

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {},
  "variables": {},
  "resources": [],
  "outputs": {}
  
  // Your code here
}

Hint

Start by creating the main structure of an ARM template with the required top-level keys.

2

Add a parameter for storage account name

Inside the parameters section, add a parameter called storageAccountName of type string.

Azure

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    // Your code here
  },
  "variables": {},
  "resources": [],
  "outputs": {}
}

Hint

Parameters allow you to pass values when deploying the template. Add the storageAccountName parameter with type string.

3

Add the storage account resource

Inside the resources array, add a resource object with type set to Microsoft.Storage/storageAccounts, apiVersion set to 2022-09-01, name set to the parameter storageAccountName, location set to eastus, sku with name as Standard_LRS, and kind set to StorageV2. Leave properties as an empty object.

Azure

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "storageAccountName": {
      "type": "string"
    }
  },
  "variables": {},
  "resources": [
    // Your code here
  ],
  "outputs": {}
}

Hint

The resource section defines what Azure resources to create. Use the parameter for the storage account name and set the required properties.

4

Add output for the storage account resource ID

Inside the outputs section, add an output called storageAccountId of type string. Set its value to the resource ID of the storage account using the ARM function resourceId with the resource type Microsoft.Storage/storageAccounts and the storage account name parameter.

Azure

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "storageAccountName": {
      "type": "string"
    }
  },
  "variables": {},
  "resources": [
    {
      "type": "Microsoft.Storage/storageAccounts",
      "apiVersion": "2022-09-01",
      "name": "[parameters('storageAccountName')]",
      "location": "eastus",
      "sku": {
        "name": "Standard_LRS"
      },
      "kind": "StorageV2",
      "properties": {}
    }
  ],
  "outputs": {
    // Your code here
  }
}

Hint

Outputs let you get information about deployed resources. Use the resourceId function to get the storage account's ID.

Practice

1. Which section in an ARM template is used to define the Azure resources you want to create?

easy

A. outputs

B. parameters

C. resources

D. variables

Solution

1. Step 1: Understand ARM template sections

   An ARM template has sections like parameters, variables, resources, and outputs.

2. Step 2: Identify the section for Azure resources

   The 'resources' section lists the Azure services and components to create.

3. Final Answer:

   resources -> Option C

4. Quick Check:

   Resources section defines Azure resources [OK]

Hint: Resources section always holds Azure resource definitions [OK]

Common Mistakes:

• Confusing parameters with resources
• Thinking variables define resources
• Mixing outputs with resource definitions

2. Which of the following is the correct way to start an ARM template JSON file?

easy

A. { "parameters": { }, "variables": { }, "resources": [ ] }

B. [ "parameters", "variables", "resources" ]

C.

D. parameters: {}, variables: {}, resources: []

Solution

1. Step 1: Recognize ARM template format

   ARM templates are JSON files with keys like parameters, variables, and resources.

2. Step 2: Check JSON syntax correctness

   { "parameters": { }, "variables": { }, "resources": [ ] } uses valid JSON object syntax with keys and empty objects/arrays.

3. Final Answer:

   { "parameters": { }, "variables": { }, "resources": [ ] } -> Option A

4. Quick Check:

   ARM templates start with JSON objects [OK]

Hint: ARM templates are JSON objects with keys, not arrays or XML [OK]

Common Mistakes:

• Using array brackets instead of object braces
• Writing XML tags instead of JSON
• Omitting quotes around keys

3. Given this ARM template snippet:

{ "parameters": { "vmName": { "type": "string" } }, "variables": { "location": "eastus" }, "resources": [ { "type": "Microsoft.Compute/virtualMachines", "name": "[parameters('vmName')]", "location": "[variables('location')]" } ] }

What will be the location of the virtual machine if the parameter vmName is set to "MyVM"?

medium

A. MyVM

B. westus

C. undefined

D. eastus

Solution

1. Step 1: Identify location value in variables

   The variable 'location' is set to "eastus" in the variables section.

2. Step 2: Understand resource location assignment

   The VM's location uses the variable 'location', so it will be "eastus" regardless of vmName.

3. Final Answer:

   eastus -> Option D

4. Quick Check:

   Location comes from variables, not parameters [OK]

Hint: Resource location uses variables, not parameters [OK]

Common Mistakes:

• Confusing vmName parameter with location
• Assuming location is from parameters
• Ignoring variable usage syntax

4. Identify the error in this ARM template snippet:

{ "parameters": { "storageName": { "type": "string" } }, "resources": [ { "type": "Microsoft.Storage/storageAccounts", "name": "storageName", "location": "eastus" } ] }

medium

A. The location value must be a variable, not a string

B. The resource name should use parameter syntax with brackets

C. Parameters section cannot be empty

D. Resource type is invalid

Solution

1. Step 1: Check resource name usage

   The resource name is set as "storageName" string, but it should reference the parameter.

2. Step 2: Correct parameter reference syntax

   Parameters are referenced with "[parameters('storageName')]" to use the parameter value.

3. Final Answer:

   The resource name should use parameter syntax with brackets -> Option B

4. Quick Check:

   Parameter references need brackets and function call [OK]

Hint: Use [parameters('name')] to reference parameters in resources [OK]

Common Mistakes:

• Using parameter name as plain string
• Thinking location must be variable
• Assuming resource type is wrong

5. You want to output the public IP address of a VM created in your ARM template. Which section should you add this output to, and what is the correct syntax to reference the IP address property named "ipAddress" from a resource named "myPublicIP"?

hard

A. Add to outputs section with "ip": { "value": "[reference('myPublicIP').ipAddress]" }

B. Add to variables section with "ip": "myPublicIP.ipAddress"

C. Add to parameters section with "ipAddress": { "type": "string" }

D. Add to resources section with "outputs": { "ip": "myPublicIP.ipAddress" }

Solution

1. Step 1: Identify output section usage

   Outputs section is used to return values after deployment, like IP addresses.

2. Step 2: Use correct syntax to reference resource property

   Use the reference() function with resource name and property: "[reference('myPublicIP').ipAddress]".

3. Final Answer:

   Add to outputs section with "ip": { "value": "[reference('myPublicIP').ipAddress]" } -> Option A

4. Quick Check:

   Outputs use reference() to get resource properties [OK]

Hint: Use outputs section and reference() function for resource properties [OK]

Common Mistakes:

• Putting outputs in variables or parameters
• Using dot notation without reference()
• Misplacing outputs inside resources