DevOps & Infrastructure

Shipping code is half the job. The other half is getting it onto a machine, keeping it there, and knowing what to do when it breaks. DevOps is that half: Linux, networks, containers, cloud, pipelines, and signals.

These lessons are written so you can debug a real box, not so you can recite a glossary. Each page walks through how the thing works, the config or commands you would actually use, and the failure modes that show up in production.

What's Inside?

The Foundations

• Linux & Networking Basics: Processes, signals, systemd, permissions, and the DNS → firewall → listen debug path.
• Web Servers & Proxies: Reverse proxies, TLS termination, a real Nginx config, and Layer 4 vs Layer 7.

Containers & Orchestration

• Containerization (Docker): Namespaces vs VMs, image layers, production Dockerfiles, Compose networking.
• Orchestration (Kubernetes): Control plane, Deployments, Services, probes, and CrashLoopBackOff.

Cloud Architecture

• Cloud Primitives & IAM: VPCs, public vs private subnets, security groups, S3, and least-privilege roles.
• Serverless Architecture: How functions run, cold starts, concurrency vs database connections, when not to use it.
• Infrastructure as Code: Terraform plan/apply/state, drift, secrets, and replaces that delete data.

Shipping & Operating

• CI/CD & GitOps: A real pipeline, SHA-tagged images, rolling/canary/blue-green, pull-based GitOps.
• Monitoring & Observability: SLIs/SLOs, RED/USE, structured logs, traces, and alerts that do not train people to ignore pages.

"If it hurts, do it more often. Bring the pain forward." — Jez Humble (Continuous Delivery)