Introduction to Cloud Computing
Cloud computing is the on-demand delivery of IT resources—including compute, databases, storage, and applications—over the internet with pay-as-you-go pricing.
🏗️ Cloud Infrastructure Architecture
Cloud architectures bridge the gap between users and physical hardware.
📊 The Service Models (SPI + F)
Cloud services are categorized by how much management is handled by the provider versus the customer.
| Model | Full Name | Focus | Example |
|---|---|---|---|
| IaaS | Infrastructure as a Service | Virtualized hardware (Servers, Storage). | AWS EC2, Azure VMs |
| PaaS | Platform as a Service | Deployment platforms for developers. | Heroku, Google App Engine |
| SaaS | Software as a Service | End-user applications. | Gmail, Slack, Jira |
| FaaS | Function as a Service | Event-driven code snippets. | AWS Lambda, Google Functions |
🏠 Deployment Models
- Public Cloud: Resources are shared between multi-tenant customers (e.g., AWS, Azure).
- Private Cloud: Infrastructure dedicated to a single organization, often on-premise.
- Hybrid Cloud: A mix of Public and Private clouds, sharing data and applications.
- Community Cloud: Shared by organizations with common interests (e.g., government or healthcare).
🤝 The Shared Responsibility Model
A critical security concept: The cloud provider is responsible for the security OF the cloud (hardware, global infrastructure), while the customer is responsible for security IN the cloud (customer data, identity management, firewall configuration).
🚀 Key Benefits for DevOps
- Elasticity: Automatically scale resources up or down based on demand.
- Cost (OpEx): Pay only for what you use; no massive upfront hardware costs.
- Global Scale: Deploy applications in regions around the world in minutes.
- Agility: Rapidly prototype and deploy new services without waiting for hardware procurement.
🏢 Top Cloud Providers
| Provider | Parent Company | Key Strength |
|---|---|---|
| AWS | Amazon | Market leader, most comprehensive toolset. |
| Azure | Microsoft | Best integration with enterprise Windows ecosystems. |
| GCP | Industry-leading data analytics and Kubernetes (GKE). |
[!IMPORTANT] Cloud Security Always implement Identity and Access Management (IAM) and Encryption as your first line of defense. In the cloud, access is the new perimeter.