Cloud Computing: Basics and Models

Cloud Basics

• Cloud refers to a global network of internet accessible servers
• These servers are used for hosting web apps and services
• Access is facilitated through web servers, such as IIS, operating on cloud virtual machines (VMs)

Cloud Providers

• Examples of cloud providers: AWS, Azure, and Google Cloud
• Cloud providers host applications and services through IaaS, PaaS, and SaaS
• They can host services publicly or privately
• Hybrid cloud environments, combining on-premises infrastructure with public cloud, are also an option

Cloud Delivery Models

• IaaS (Infrastructure as a Service): Requires renting virtualized computing resources like VMs, storage, and networks, while managing the OS, middleware, runtime, apps, and data (e.g., Azure VM)
• PaaS (Platform as a Service): Focuses on application development, with the provider managing everything else like Azure App Services and Google App Engine
• SaaS (Software as a Service): Provides fully managed software accessed via the web, exemplified by Google Workspace and Microsoft 365
• XaaS: Is a general term for "Anything as a Service"

Cloud Storage Types

• Block Storage: Structured like a virtual hard drive, faster performance making it ideal for databases and virtual machines
• Object Storage (BLOB): Stores files as objects with metadata and is suitable for unstructured data like images and videos
• Binary Large Object (BLOB): File types stored in object storage, such as audio and images

Continuous Deployment (CD)

• Automated to build, test, and deploy code
• Requires code repositories (e.g., GitHub), build automation tools (e.g., Jenkins, GitLab CI), and orchestration tools
• CD is a key part of DevOps workflows

Internet Information Services (IIS)

• Web server software to host websites and apps on Windows Server
• Installed via Server Manager or PowerShell
• IIS Manager provides a GUI for configuration
• Supports protocols like HTTP/S, FTP, WebDAV and WebSocket
• An open-source alternative to IIS is Apache Web Server

IIS components

• Virtual Directory: Logical pointer to a physical folder on disk, allowing web apps to be accessed via structured URLs.
• Application Pools: Isolate apps for reliability and security where each pool has its own worker process (w3wp.exe).

Supported Interfaces & Extensions

• CGI, ISAPI, ODBC provide support for dymanic content
• SSI includes extrenal content in pages
• WebSocket allows for persistent two way communication
• WebDAV enables web based file management

Web App Technologies

• Web App Frameworks include: Django, Node.js and ASP.NET
• Web app files include: HTML, CGI and ISAPI

Containers on Windows Server 2019

• Docker EE (Enterprise Edition) is required to run containers
• The docker command in the CLI pulls images, runs containers, and manages apps
• Types of containers are Windows Containers, Hyper-V Containers and Linux Containers on Windows (LCOW)
• Nano Server requires Hyper-V isolation

Docker EE Components

• Docker client is a CLI tool to interact with Docker
• Docker daemon manages containers/images
• Docker Hub is a public registry for images

Container Images

• Container images are immutable and executable
• Container Image is a read only snapshot used to create a container

Linux Containers on Windows (LCOW) & LinuxKit

• LCOW is for running Linux containers on Windows
• LinuxKit is a toolkit to build minimal Linux OS for containers

Windows Subsystem for Linux (WSL)

• Runs Linux distros directly on Windows
• Allows to run Linux native web apps
• Choose a distro (like Ubuntu) via Microsoft Store

Group Policy

• GPOs (Group Policy Objects): Control configuration of users and computers
• Edit using Group Policy Management Editor
• Linked to Sites, Domains, or OUs

Configuration Types

• Computer Configuration: Applies during boot and affects system-level settings
• User Configuration: Applies at logon and affects user profiles

GPO Categories

• Software Settings: Install/manage applications
• Windows Settings: Scripts, security settings, folder redirection
• Administrative Templates: Registry-based policies

Preferences vs Policies

• Preferences: User can override, more flexible
• Policies: Enforced and user cannot override

Certificates and PKI

• PKI (Public Key Infrastructure) establishes trust using certificates

PKI Components

• CA (Certificate Authority): Issues and verifies certs
• Root CA: Top-level, must be trusted
• Subordinate CA: Issues certs on behalf of root

Certificate Concepts

• Public Key Certificate: Binds a public key to an identity
• Digital Signature: Verifies authenticity/integrity
• Auto-Enrollment: Users/computers get certs automatically via GPO

Tools & Concepts

• Certificate Templates Console
• CA Hierarchy: Trust chain structure
• CRL / OCSP: Used to check revocation status

Network Security & Updates

• 802.1X
  • Wired & Wireless security protocol
  • Works with RADIUS to authenticate clients before granting access
  • PEAP is an encrypted authentication tunnel
• WSUS (Windows Server Update Services)
  • Local management of Windows updates
  • GPOs configure when/how clients check WSUS
• Microsoft Defender
  • Antivirus, firewall, and IPSec in one
  • Controlled Folder Access prevents ransomware
  • Core Isolation / Memory Integrity protects from kernel-level threats

Other Important Concepts & Tools

• Windows Defender Firewall
  • Controlled via Group Policy or Windows Defender Firewall with Advanced Security
  • Configure firewall rules, connection security rules (IPSec)
• Windows Installer & Internal Database
  • Used for deploying apps via GPO
  • WID is used by WSUS
• Hashes & Checksums
  • Used for verifying file integrity
  • SHA/MD5 common in digital signatures
• WMI Filters
  • Target GPOs based on system attributes (e.g., OS version)

Key Terms

• Docker EE: Enterprise container platform
• Container Image: Blueprint for creating containers
• Orchestration: Automates deployment/management of containers
• LCOW: Linux Containers on Windows
• WebDAV: Edit/manage files over HTTP
• ISAPI/CGI: Interfaces for server-side processing
• Virtual Directory: Alias to a physical folder in IIS
• Application Pool: Isolated environment for web apps
• BLOB Storage: Stores unstructured data (media, files)
• Distribution (Distro): A version of a Linux OS
• WSL: Run Linux on Windows natively