Bicep Tutorials using Azure

1. What is Bicep?

Bicep is a Domain-Specific Language (DSL) that simplifies the process of defining Azure resources using Infrastructure as Code (IaC). It is designed as a replacement for Azure Resource Manager (ARM) templates, which can be difficult to maintain due to their verbosity and complexity.

Key Features of Bicep:

• Declarative syntax: Simple and human-readable code.
• Modularization: Easy to split templates into reusable modules.
• Direct integration with Azure: Compiles to ARM JSON, ensuring backward compatibility.
• Error prevention: Type safety, intellisense in VS Code, and built-in validation.
• First-class support for Azure services: Includes support for every Azure resource.

How Bicep Works?

How Bicep Works in 3 Steps:

1. Write the Bicep Code: Define your Azure infrastructure using the Bicep DSL.
2. Compile Bicep to ARM JSON: Bicep is automatically transpiled to an ARM template (JSON) before deployment. When you deploy a Bicep template, it is automatically compiled into an ARM template (JSON). You don’t have to manually convert the Bicep file; the Azure CLI or PowerShell will handle the conversion for you.
3. Deploy the ARM Template: The compiled ARM template is deployed using the Azure CLI, PowerShell, or REST API.

How Bicep Interacts with Azure Resource Manager (ARM)

ARM (Azure Resource Manager) is the central service responsible for managing and deploying resources in Azure. It handles the following tasks:

• Parsing and validating deployment templates.
• Orchestrating resource creation, modification, or deletion.
• Managing dependencies between resources (e.g., ensuring that a Virtual Network is created before deploying Virtual Machines that depend on it).

Bicep simply generates ARM-compatible JSON templates, which ARM then processes. The interaction flow looks like this:

1. Bicep generates a simplified deployment script.
2. Azure CLI or Azure PowerShell compiles the Bicep script into ARM JSON templates.
3. Azure Resource Manager reads the ARM template, resolves dependencies, and deploys resources to Azure.
4. ARM ensures the deployment is idempotent, meaning multiple executions of the same template result in the same final state without duplicating resources.

How Bicep Improves on ARM Templates?

• Cleaner Syntax: Bicep is much more readable and concise compared to raw JSON in ARM templates.
• No Manual JSON Writing: You don’t have to hand-write or maintain JSON templates, as Bicep handles the complex details automatically.
• Better Tooling: Bicep has great tooling support in VS Code with features like IntelliSense, syntax highlighting, and error detection.
• Reusability: Bicep supports the use of modules, which makes it easier to organize and reuse code.
• Built-in Error Checking: Bicep provides early feedback on errors with better validation and linting support.

Comparison of Bicep and ARM templates

Here’s a comparison of Bicep and ARM templates in a tabular format:

Comparison of Bicep and Terraform.

Here’s a detailed comparison of Bicep and Terraform in a tabular format:

Azure Bicep terminology

Here’s a table of Azure Bicep terminology with definitions to help you understand the key terms used in Bicep:

Key Concepts:

• Bicep simplifies and abstracts away complex JSON-based ARM templates.
• Resources, parameters, variables, and modules are the building blocks of Bicep templates.
• Modules enable reusability and modularization of infrastructure code.
• Outputs and functions are used for passing information between resources or deployments.
• Loops and conditions allow for dynamic and flexible resource deployment.
• Compile and decompile commands help transition between ARM and Bicep formats.

2. Prerequisites for Bicep

Before starting with Bicep, you need a few tools installed on your machine:

• Azure CLI or Azure PowerShell: To interact with Azure.
• Bicep CLI: If you prefer a standalone tool, though it’s integrated into the Azure CLI as well.
• Visual Studio Code (VS Code): For editing Bicep files.
  • Install the Bicep extension in VS Code for syntax highlighting, autocomplete, and linting.

Installing Bicep CLI

• To install Bicep via Azure CLI, run:

az bicep install
az bicep version

3. Writing Your First Bicep Template

Here’s a basic example that defines an Azure Storage Account:

Basic Bicep Template (main.bicep)

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-04-01' = {
  name: 'mystorageaccount'
  location: resourceGroup().location
  sku: {
    name: 'Standard_LRS'
  }
  kind: 'StorageV2'
}

Explanation:

• resource: Defines an Azure resource.
• Microsoft.Storage/storageAccounts@2021-04-01: Specifies the resource type and API version.
• name: Specifies the name of the resource.
• location: Uses the resource group’s location.
• sku: Defines the SKU (pricing tier) for the Storage Account.
• kind: Specifies the type of storage.

4. Deploying a Bicep Template

You can deploy a Bicep template using the Azure CLI or Azure PowerShell.

Using Azure CLI

To deploy a Bicep file to a resource group:

az deployment group create --resource-group <resource-group-name> --template-file main.bicep

# Using Azure PowerShell
New-AzResourceGroupDeployment -ResourceGroupName <resource-group-name> -TemplateFile main.bicep

This command will deploy the main.bicep template to the specified resource group.

5. Parameters and Variables in Bicep

Parameters:

You can define parameters to make your template reusable and configurable during deployment.

param storageAccountName string
param location string = resourceGroup().location

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-04-01' = {
  name: storageAccountName
  location: location
  sku: {
    name: 'Standard_LRS'
  }
  kind: 'StorageV2'
}

Using Parameters:

Deploy the template while providing parameter values:

az deployment group create --resource-group <resource-group-name> --template-file main.bicep --parameters storageAccountName='mystorageaccount'

Variables:

You can use variables to simplify complex logic or create calculated values.

var storageNamePrefix = 'mystorage'
var storageAccountName = '${storageNamePrefix}account'

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-04-01' = {
  name: storageAccountName
  location: resourceGroup().location
  sku: {
    name: 'Standard_LRS'
  }
  kind: 'StorageV2'
}

6. Loops and Conditions in Bicep

Loops:

Loops are useful for deploying multiple resources or configuring multiple settings in a concise way.

Example: Deploy Multiple Storage Accounts

param storageAccountNames array = [
  'storageaccount1'
  'storageaccount2'
  'storageaccount3'
]

resource storageAccounts 'Microsoft.Storage/storageAccounts@2021-04-01' = [for name in storageAccountNames: {
  name: name
  location: resourceGroup().location
  sku: {
    name: 'Standard_LRS'
  }
  kind: 'StorageV2'
}]

This loop creates three storage accounts, each with the name provided in the array.

Conditions:

You can use conditions to deploy resources based on a Boolean value or some other logic.

Example: Conditionally Deploy a Storage Account

param createStorageAccount bool = true

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-04-01' = if (createStorageAccount) {
  name: 'mystorageaccount'
  location: resourceGroup().location
  sku: {
    name: 'Standard_LRS'
  }
  kind: 'StorageV2'
}

7. Outputs in Bicep

You can define outputs in your Bicep templates to return values after deployment. These outputs can be useful for chaining deployments or retrieving important information like resource IDs.

Example: Output Storage Account ID

output storageAccountId string = storageAccount.id
output storageAccountLocation string = storageAccount.location

8. Using Bicep Modules

Modules allow you to break down your Bicep files into reusable components, making it easier to manage large and complex templates.

Module Example:

Main Template (main.bicep)

module storageModule './storage.bicep' = {
  name: 'StorageModule'
  params: {
    storageAccountName: 'mystorageaccount'
    location: 'eastus'
  }
}

Storage Module (storage.bicep)

param storageAccountName string
param location string

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-04-01' = {
  name: storageAccountName
  location: location
  sku: {
    name: 'Standard_LRS'
  }
  kind: 'StorageV2'
}

This modular approach allows for better organization and reusability of code.

9. Best Practices with Bicep

1. Use Parameters and Outputs:

• Use parameters to generalize templates and make them reusable across environments.
• Use outputs to expose important information from one template to another.

2. Modularize Templates:

• Break large templates into smaller modules for easier maintenance and reusability.

3. Leverage the VS Code Bicep Extension:

• The Bicep extension for VS Code provides rich tooling, including syntax highlighting, error detection, and auto-completion.

4. Store and Manage Bicep Files in Version Control:

• Store your Bicep files in a Git repository. Treat them like application code to maintain version control and enable collaboration.

5. Test Templates in Development Environments:

• Test your Bicep templates in development or staging environments before deploying to production. This ensures no surprises during production deployment.

10. Advanced Scenarios with Bicep

Using Existing Resources:

You can reference existing resources within your Bicep template. This is useful when deploying resources that depend on resources already deployed.

resource existingVnet 'Microsoft.Network/virtualNetworks@2020-11-01' existing = {
  name: 'myExistingVnet'
}

Complex Logic with Functions:

Bicep supports Azure Resource Manager functions like concat(), length(), uniqueString(), etc.

Example:

var uniqueStorageName = uniqueString(resourceGroup().id)

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-04-01' = {
  name: uniqueStorageName
  location: resourceGroup().location
  sku: {
    name: 'Standard_LRS'
  }
  kind: 'StorageV2'
}

11. Testing Bicep Templates Locally

You can test and validate Bicep templates without deploying them to Azure by using the what-if feature.

Preview the Deployment:

az deployment group what-if –resource-group –template-file main.bicep

This will show you the expected changes without actually deploying them.

12. Conversion between ARM Templates and Bicep

Convert ARM to Bicep:

You can convert existing ARM templates into Bicep templates using the Azure CLI.

az bicep decompile --file <template.json>
This will generate a .bicep file from the ARM template.

Convert Bicep to ARM JSON:

Bicep is automatically compiled into ARM JSON when you deploy it, but you can also convert it manually.

az bicep build --file <file.bicep>

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