Q11-Q15(ARM)

Q11: What are Linked Templates? How Linked and Nested templates are related in ARM Templates?

Q12: How do you handle conditional deployments in ARM templates?

Q13: What is the difference between Parameter and Variable in ARM template?

Q14: What are ARM templates. What is the basic structure of ARM templates?

Q15:

===============================================================================

 Q11: What are Linked Templates? How Linked and Nested templates are related in ARM Templates?

Answer:

Linked templates are ARM templates that are referenced from a parent template using a URL. They help in modularizing and reusing templates.

Relationship Between Linked and Nested Templates

• If the child template is embedded n parent template than it is Nested Template
• If the child template is referenced by a url then it is Linked Template
• Both Nested and Linked templates can accept parameters from their parent template.
• Both Nested and Linked templates can return output to their parent template, enables to retrieve the important information required in subsequent deployment and configuration.

Usage Example:

We could use a linked template to reference a reusable module stored in a central repository and a nested template to handle a specific part of the deployment logic within the main template.

===============================================================================

Q12: How do you handle conditional deployments in ARM templates?

Answer:

Conditional deployments can be handled using the condition element, which allows resources to be deployed based on certain conditions.

Below are the few examples of Conditional deployments usages:

1. New or Existing Storage Account: In ARM templates we can have condition like create a storage account if it doesnt exits otherwise use the existing one. 

2. Deployment based on condition: We can take parameter from user and put it condition element to deploy or not. Eg deploying a VM based on value given to parameter "deployVM"

"condition": "[parameters('deployVM')]"

===============================================================================

Q13: What is the difference between Parameter and Variable in ARM template?

Answer:

In ARM templates both Parameters and Variables are used to make my ARM template more flexible and reusable,

Parameters 

• Purpose: Accepts input from the user or a deployment process.
• Scope: Dynamic; values are provided at deployment time.
• Use case: When you want the template to work for multiple environments, regions, or resource names without editing the template.
• Allow you to pass values into the template at deployment time, making the template reusable and flexible. You define parameters in the parameters section and reference them in the resources section.

"parameters": {
  "storageAccountName": {
    "type": "string",
    "defaultValue": "mystorageacct",
    "metadata": {
      "description": "Name of the storage account"
    }
  }
}

-------------
Usage in resource 
"name": "[parameters('storageAccountName')]"
---------------
When deploying, you can override storageAccountName to devstorage001 or prodstorage001.

<<Separator>><<Separator>><<Separator>><<Separator>>

variables 

• Purpose: Holds calculated or intermediate values inside the template.
• Scope: Internal to the template; cannot be overridden at deployment time.
• Use case: To simplify expressions, avoid repeating the same logic, or construct dynamic names.
• are values defined within the template itself and used to simplify template expressions.

-----------

"variables": {

  "storageAccountNameFull": "[concat(parameters('storageAccountName'), '001')]"

}

-----------------

"name": "[variables('storageAccountNameFull')]"

--------------

Here, the variable storageAccountNameFull appends '001' to whatever the user provides in parameters('storageAccountName').

Feature	Parameter	Variable
Input Source	Provided at deployment time	Calculated inside the template
Modifiable at Runtime	Yes	No
Use Case	Configurable values, environment-specific settings	Reusable expressions, dynamic names, intermediate values
Example	[parameters('location')]	[variables('fullStorageName')]

===============================================================================

Q14: What are ARM templates. What is the basic structure of ARM templates?

Answer:

ARM- Azure Resource Manager Template. Its a way of defining your infrastructure as code. IaC. 

ARM templates are JSON files that define the infrastructure and configuration for your Azure solution. 

Key Points about ARM Templates

• Declarative: You define what you want, not how to create it. Azure takes care of provisioning.

• JSON format: ARM templates are written in JSON (or Bicep for a more readable syntax).

• Idempotent: Deploying the same template multiple times does not create duplicate resources.

• Parameterization: You can make templates reusable across environments using parameters.

• Supports dependencies: You can define how resources depend on each other.

------------BASIC STRUCTURE --------------

{

  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",

  "contentVersion": "1.0.0.0",

  "parameters": { },       // Optional - values passed at deployment time

  "variables": { },        // Optional - internal calculated values

  "functions": { },        // Optional - user-defined functions for reuse

  "resources": [ ],        // Required - array of Azure resources to deploy

  "outputs": { }           // Optional - values returned after deployment

}

• $schemA- Links to the ARM template JSON schema for validation and IntelliSense.
• contentVersion - Template versioning. Helps manage template updates.
• parameters - Input values at deployment time. Example: location, resource names, sizes.
• variables- Internal values or expressions used in the template.
• resources- The core part. Each item defines an Azure resource, like a VM, storage account, or network.
• outputs- Values returned after deployment, which can be used in scripts or other templates.

===============================================================================

q`1/

===============================================================================