Azure Management and Deployment Tools: AZ-900 Cram Sheet

This guide focuses on the tools and interfaces used to interact with Azure, as well as the underlying management layer (Azure Resource Manager) that ensures consistency across all deployment methods.

## Topic Weighting

[!IMPORTANT] For the AZ-900 exam, you must distinguish between when to use a GUI (Portal) versus when to use command-line/automation tools (CLI, PowerShell, ARM Templates).

## Key Concepts Summary

1. The Management Interfaces

• Azure Portal: A web-based Graphical User Interface (GUI). Best for beginners, one-off tasks, and visual resource monitoring.
• Azure Cloud Shell: A browser-based terminal accessible from the portal. It includes pre-installed tools (Azure CLI, PowerShell, Git) and persists files in an attached storage account.
• Azure CLI: A cross-platform command-line interface. Uses bash-style syntax (e.g., az group create).
• Azure PowerShell: A set of modules for managing Azure via PowerShell cmdlets (e.g., New-AzResourceGroup).

2. Infrastructure as Code (IaC) & ARM

• Azure Resource Manager (ARM): The deployment and management service. It provides a management layer that allows you to create, update, and delete resources in your Azure account.
• ARM Templates: JavaScript Object Notation (JSON) files that define the infrastructure and configuration for your project. They are declarative, meaning you describe what you want, not how to build it.
• Azure Arc: Extends Azure management and governance to resources running outside of Azure (on-premises, AWS, or GCP).

## Common Pitfalls

• ❌ Mistake: Thinking Azure CLI and Azure PowerShell are the same.
  • ✅ Reality: CLI uses the az command (Bash-friendly); PowerShell uses Verb-Noun cmdlets like Get-AzVM.
• ❌ Mistake: Assuming the Portal is more powerful than the CLI.
  • ✅ Reality: ARM Templates and CLI/PowerShell are often better for repetitive tasks or large-scale deployments due to automation (Idempotency).
• ❌ Mistake: Believing Azure Arc moves your data to Azure.
  • ✅ Reality: Azure Arc only moves the management (the "Control Plane") to Azure; your data stays on your local server or other cloud.

## Mnemonics / Memory Triggers

• ARM = The Brain: Everything you do goes through the Azure Resource Manager. It is the single gatekeeper for all requests.
• Declarative vs. Imperative:
  • ARM Templates (Declarative): "I want a ham sandwich." (Result-oriented)
  • CLI/Scripts (Imperative): "Buy bread, buy ham, put ham on bread." (Step-oriented)
• The "Cloud Shell" Storage Requirement: Remember that Cloud Shell requires an Azure Storage Account to persist your files across sessions.

## Formula / Equation Sheet

ARM Template Structure

An ARM Template is a JSON file with four main sections:

Tool Selection Matrix

## Practice Set

1. Which tool provides a browser-based terminal that allows for both Bash and PowerShell environments? Answer: Azure Cloud Shell.

2. A company wants to ensure that 50 Web Apps are deployed exactly the same way every time. Which concept should they use? Answer: Infrastructure as Code (IaC) using ARM Templates.

3. True or False: You can use Azure CLI on a machine running macOS. Answer: True (Azure CLI is cross-platform).

4. Which Azure service acts as the orchestration layer for all requests sent to Azure? Answer: Azure Resource Manager (ARM).

5. Visualizing the Deployment Flow (TikZ)

\begin{tikzpicture} [node distance=2cm, auto, >=latex', block/.style={rectangle, draw, fill=blue!10, text width=5em, text centered, rounded corners, minimum height=3em}, cloud/.style={draw, ellipse, fill=red!10, node distance=3cm, minimum height=2em}]

\node [block] (user) {User Tools (CLI/Portal)}; \node [block, right of=user, xshift=2cm, fill=green!10] (arm) {ARM API Layer}; \node [block, right of=arm, xshift=2cm] (res) {Azure Resources};

\draw [->, thick] (user) -- node {REST API} (arm); \draw [->, thick] (arm) -- node {Provision} (res);

\node [below of=arm, yshift=1cm] (policy) {\small \textit{Checks Policies & Locks}}; \draw [dashed] (arm) -- (policy); \end{tikzpicture}

[!TIP] Remember: Idempotency is a key feature of ARM Templates. It means you can run the same template multiple times and it will always result in the same environment state without breaking existing resources.