Azure CLI installation and login - Deep Dive

Overview - Azure CLI installation and login

What is it?

Azure CLI is a tool that lets you talk to Microsoft Azure using simple commands typed in a terminal or command prompt. Installing it means putting this tool on your computer so you can use it anytime. Logging in means connecting the tool to your Azure account so it knows who you are and what you can do. This lets you manage your cloud resources easily without using a web browser.

Why it matters

Without Azure CLI, managing cloud resources would mean clicking through many pages on a website, which is slow and hard to automate. Azure CLI makes it fast and repeatable to create, change, or delete resources. This saves time and reduces mistakes, especially when managing many resources or doing the same tasks often.

Where it fits

Before learning Azure CLI installation and login, you should understand what cloud computing is and have a basic idea of Azure services. After this, you can learn how to use Azure CLI commands to create and manage resources, automate tasks, and integrate with scripts or other tools.

Mental Model

Core Idea

Azure CLI is like a remote control that lets you command your cloud resources quickly and securely from your computer.

Think of it like...

Imagine you have a universal remote control for your TV and other devices. Installing Azure CLI is like getting that remote and setting it up. Logging in is like pairing the remote with your TV so it knows which device to control.

┌─────────────────────┐
│  Your Computer      │
│  (Terminal/Command) │
└─────────┬───────────┘
          │
          │ Azure CLI Installed
          │
┌─────────▼───────────┐
│  Azure CLI Tool     │
│  (Commands typed)   │
└─────────┬───────────┘
          │
          │ Login with your Azure Account
          │
┌─────────▼───────────┐
│  Azure Cloud        │
│  (Resources managed)│
└─────────────────────┘

Build-Up - 6 Steps

1

Foundation

What is Azure CLI and why use it

Concept: Introduce Azure CLI as a command-line tool for managing Azure resources.

Azure CLI is a program you install on your computer. It lets you type commands to create, update, or delete cloud resources like virtual machines or storage. This is faster and easier than clicking through the Azure website, especially for repeated tasks.

Result

You understand that Azure CLI is a tool to control Azure from your computer using commands.

Knowing what Azure CLI is helps you see why installing and logging in is the first step to managing Azure efficiently.

2

Foundation

Installing Azure CLI on your computer

Concept: Learn how to download and install Azure CLI on different operating systems.

To install Azure CLI: - On Windows: Download the installer from the official Azure website and run it. - On macOS: Use Homebrew with the command 'brew install azure-cli'. - On Linux: Use your package manager, for example, 'sudo apt-get install azure-cli' on Ubuntu. After installation, open your terminal and type 'az --version' to check it works.

Result

Azure CLI is installed and ready to use on your computer.

Understanding installation steps ensures you have the tool ready before trying to manage Azure.

3

Intermediate

Logging into Azure CLI securely

🤔Before reading on: do you think logging in requires typing your password every time you run a command, or just once per session? Commit to your answer.

Concept: Learn how to authenticate Azure CLI with your Azure account using a login command.

To log in, type 'az login' in your terminal. This opens a browser window asking you to enter your Azure username and password. After successful login, the CLI remembers your session so you don't have to log in again for a while. You can now run commands that affect your Azure resources.

Result

You are connected to your Azure account through Azure CLI and can manage resources.

Knowing that login is a one-time session per terminal session helps you work efficiently without repeated interruptions.

4

Intermediate

Using service principals for automated login

🤔Before reading on: do you think interactive login is suitable for automated scripts, or is there a better way? Commit to your answer.

Concept: Introduce service principals as a way for scripts to log in without human interaction.

For automation, use a service principal, which is like a robot user with permissions. Create it with 'az ad sp create-for-rbac' and save the output credentials. Then log in using 'az login --service-principal -u -p --tenant '. This lets scripts run Azure commands securely without manual login.

Result

Scripts can log in and manage Azure resources automatically using service principals.

Understanding service principals unlocks automation possibilities and secure script execution.

5

Advanced

Managing multiple Azure accounts and subscriptions

🤔Before reading on: do you think Azure CLI can handle multiple accounts at once, or only one? Commit to your answer.

Concept: Learn how Azure CLI manages multiple accounts and subscriptions and how to switch between them.

Azure CLI can store multiple login sessions. Use 'az account list' to see all subscriptions you have access to. Use 'az account set --subscription ' to switch the active subscription. This controls which resources your commands affect.

Result

You can work with multiple Azure accounts and subscriptions seamlessly in one CLI environment.

Knowing how to switch accounts prevents mistakes like changing resources in the wrong subscription.

6

Expert

Token caching and session expiration details

🤔Before reading on: do you think Azure CLI stores your login tokens securely and refreshes them automatically, or do you need to log in manually every time? Commit to your answer.

Concept: Understand how Azure CLI caches authentication tokens and handles session expiration behind the scenes.

When you log in, Azure CLI saves tokens locally in a secure file. These tokens allow it to authenticate without asking for your password again. Tokens expire after some time, but Azure CLI automatically refreshes them if possible. If refresh fails, you must log in again. This process is transparent to you but ensures security.

Result

Azure CLI manages authentication tokens securely and refreshes sessions automatically, balancing convenience and security.

Understanding token caching explains why sometimes you need to log in again and how Azure CLI keeps your sessions secure.

Under the Hood

Azure CLI is a command-line program that sends requests to Azure's REST APIs. When you log in, it obtains an access token from Azure Active Directory (AAD), which proves your identity. This token is stored locally and attached to each request to authenticate you. The CLI manages token expiration by refreshing tokens using refresh tokens without user input until they expire or are revoked.

Why designed this way?

Azure CLI was designed to provide a simple, scriptable interface to Azure services. Using tokens from AAD allows secure, standardized authentication without exposing passwords. Token caching improves user experience by reducing repeated logins. Alternatives like password-based authentication were rejected due to security risks and poor automation support.

┌───────────────┐       ┌─────────────────────┐       ┌───────────────┐
│ User Terminal │──────▶│ Azure CLI Tool      │──────▶│ Azure REST API │
│ (Commands)    │       │ (Token Management)  │       │ (Cloud)       │
└───────────────┘       └─────────┬───────────┘       └───────────────┘
                                   │
                                   │
                          ┌────────▼────────┐
                          │ Azure Active    │
                          │ Directory (AAD) │
                          └─────────────────┘

Myth Busters - 4 Common Misconceptions

Quick: Does 'az login' require internet every time you run a command? Commit yes or no.

Common Belief: Once logged in, you can run Azure CLI commands offline without internet.

Reality: Azure CLI requires internet to communicate with Azure services for every command, even after login.

Why it matters: Trying to run commands offline leads to errors and confusion, blocking work unexpectedly.

Quick: Can you use the same Azure CLI login session across different computers? Commit yes or no.

Common Belief: Logging in once on one computer lets you use Azure CLI on any other computer without logging in again.

Reality: Login sessions are local to each computer; you must log in separately on each device.

Why it matters: Assuming shared sessions causes failed commands on new devices and wasted troubleshooting time.

Quick: Is using your personal login for automation scripts a good practice? Commit yes or no.

Common Belief: It's fine to use your personal Azure login for running automated scripts in Azure CLI.

Reality: Using personal login for automation is insecure and can cause permission issues; service principals are recommended.

Why it matters: Using personal credentials risks accidental exposure and breaks automation when passwords change.

Quick: Does Azure CLI automatically switch subscriptions when you log in? Commit yes or no.

Common Belief: Azure CLI always uses the correct subscription automatically after login without manual switching.

Reality: You must manually select the subscription if you have access to multiple; otherwise, commands may affect the wrong resources.

Why it matters: Not switching subscriptions can lead to modifying or deleting unintended resources, causing costly mistakes.

Expert Zone

1

Azure CLI token cache files are encrypted and stored per user profile, preventing token sharing between users on the same machine.

2

Service principals can have limited permissions scoped to specific resource groups, enhancing security for automation.

3

Azure CLI supports multiple authentication methods including device code login and managed identities, useful in different environments.

When NOT to use

Azure CLI is not ideal for complex workflows requiring conditional logic or error handling; in such cases, use Azure SDKs or Infrastructure as Code tools like Terraform or ARM templates.

Production Patterns

In production, teams use service principals with least privilege for automation, store credentials securely in secret managers, and integrate Azure CLI commands into CI/CD pipelines for repeatable deployments.

Connections

OAuth 2.0 Authentication

Azure CLI login uses OAuth 2.0 protocol to obtain access tokens from Azure Active Directory.

Understanding OAuth 2.0 helps grasp how Azure CLI securely authenticates without exposing passwords.

Infrastructure as Code (IaC)

Azure CLI commands can be scripted to automate infrastructure deployment, complementing IaC tools.

Knowing Azure CLI basics enables smoother transition to IaC practices for scalable cloud management.

SSH Key Authentication

Like SSH keys provide secure login to servers, Azure CLI uses tokens for secure access to cloud resources.

Recognizing parallels in authentication methods across domains deepens understanding of secure access principles.

Common Pitfalls

#1 Trying to run Azure CLI commands without logging in first.

Wrong approach:

az vm list

Correct approach:

az login
az vm list

Root cause:

Not understanding that Azure CLI requires authentication before accessing resources.

#2 Using personal login credentials in automation scripts.

Wrong approach:

az login
# script runs with personal account

Correct approach:

az login --service-principal -u -p --tenant
# script runs with service principal

Root cause:

Lack of knowledge about secure, non-interactive login methods for automation.

#3 Assuming the default subscription is always correct after login.

Wrong approach:

az vm delete --name myVM

Correct approach:

az account set --subscription
az vm delete --name myVM

Root cause:

Not verifying or switching to the intended subscription before running commands.

Key Takeaways

Azure CLI is a command-line tool that lets you manage Azure cloud resources quickly and efficiently.

Installing Azure CLI on your computer is the first step to using it, and logging in connects it securely to your Azure account.

For automation, use service principals instead of personal logins to keep credentials safe and scripts reliable.

Azure CLI manages authentication tokens behind the scenes, refreshing them to keep your session active without repeated logins.

Always verify which Azure subscription is active in your CLI session to avoid affecting the wrong resources.