Azure provides multiple ways to connect, automate, and interact with it. All method require users and codes to be authenticated with valid credentials before they can be used.

• Azure portal
• PowerShell
• Azure Command Line Interface (CLI)
• Azure REST API

Azure portal is a great place to get started. With the Azure portal, users can log in and start creating and managing Azure resources manually. The portal provides an intuitive and user-friendly user interface through the browser. The Azure portal provides an easy way to navigate to resources using blades. The blades display all properties of a resource, logs, cost, its relationship with other resources, tags, security options, and more. The entire cloud deployment can be managed through the portal.

PowerShell is an object-based command-line shell and scripting language used for administration, configuration, and management of infrastructure and environments. It is built on top of the .NET framework and provides automation capabilities. PowerShell has truly become a first-class citizen among IT administrators and automation developers for managing and controlling the Windows environment. Today, almost every Windows and many Linux environments can be managed by PowerShell. In fact, almost every aspect of Azure can also be managed by PowerShell. Azure provides rich support for PowerShell. It provides a PowerShell module for each resource provider containing hundreds of cmdlets. Users can use these cmdlets in their scripts to automate interacting with Azure. Azure PowerShell module is available through the web platform installer as well as through the PowerShell Gallery. Windows Server 2016 and Windows 10 provides package management and PowerShellGet modules for quick and easy downloads and installation of PowerShell modules from the PowerShell gallery. The PowerShellGet module provides the Install-Module cmdlet for downloading and installing modules on the system. Installing a module is a simple act of copying the module files at well-defined module locations:

Import-module PowerShellGet
Install-Module -Name AzureRM -verbose  

Azure also provides Azure CLI 2.0 that can be deployed on Linux, Windows, as well as Mac operating systems. The Azure CLI 2.0 is Azure's new command-line utility for managing Azure resources. Azure CLI 2.0 is optimized for managing and administering Azure resources from the command line, and for building automation scripts that work against the Azure Resource Manager. The command-line interface can be used to execute commands using Bash Shell or Windows command line. Azure CLI is a very famous non-Windows user as it allows us to talk to Azure on Linux and Mac. Steps for installing Azure CLI 2 are available at https://docs.microsoft.com/en-us/cli/azure/install-azure-cli?view=azure-cli-latest.

All Azure resources are exposed to users through REST endpoints. Representational State Transfer (REST) APIs are service endpoints that implement HTTP operations (methods), providing create, retrieve, update, or delete (CRUD) access to the service's resources. Users can consume these API's to create and manage resources. In fact, the CLI and PowerShell mechanism uses these REST API's internally to interact with resources on Azure.

In an earlier section, we witnessed deployment features such as multi-service, multi-region, extensible, and idempotent provided by the ARM. ARM templates are primary means of provisioning resources in the ARM. ARM templates provide implementation support for ARM deployment features.

ARM templates provide a declarative model through which resources, their configuration, scripts, and extensions are specified. ARM templates are based on JavaScript Object Notation (JSON) format. They use the JSON syntax and conventions to declare and configure resources. JSON files are text-based, human-friendly, and easily readable files.

They can be stored in a source code repository and have version control. They are also a means to represent IAC that can be used to provision resources in an Azure resource group again and again, predictably, consistently, and uniformly. A template needs a resource group for deployment. It can only be deployed to a resource group and the resource group should exist before executing a template deployment. A template is not capable of creating a resource group.

Templates provide the flexibility to be generic and modular in their design and implementation. Templates provide the ability to accept parameters from users, declare internal variables, help in defining dependencies between resources, link resources within same or different resource groups, and execute other templates. They also provide scripting language type expressions and functions that make them dynamic and customizable at runtime.

PowerShell allows two modes of deployment of templates:

• Incremental
• Complete

Incremental deployment adds resources declared in the template that doesn't exist in a resource group, leaves resources unchanged in a resource group that is not part of a template definition, and leaves resources unchanged in a resource group that exists in both the template and resource group with the same configuration state.

Complete deployment, on the other hand, adds resources declared in a template to the resource group, deletes resources that do not exist in the template from the resource group, and leaves resources unchanged that exist in both the resource group and template with the same configuration state.