# Phase 2 - Platform And Delivery Core

This phase is about building the platform layer: cloud resources, pipelines, containers, Kubernetes, and infrastructure as code.

## Goal

By the end of this phase, you should be able to take an application from source code to a repeatable deployment running on cloud infrastructure.

## Study Order

1. `../../04_Infrastructure_as_Code_and_Cloud/Cloud_Services/README.md`
2. `../../02_Version_Control_and_CI_CD/Jenkins_CICD/README.md`
3. `../../02_Version_Control_and_CI_CD/Jenkins_CICD/end-to-end-ci-cd-pipeline.md`
4. `../../03_Containers_and_Orchestration/README.md`
5. `../../04_Infrastructure_as_Code_and_Cloud/Terraform/README.md`
6. `../../07_Interview_Preparation/interview-questions-easy.md`
7. `../../07_Interview_Preparation/interview-questions-medium.md`

## What To Master

### Cloud Platform Basics

* compute, storage, networking, IAM, and managed services
* public versus private networking
* why availability zones and regions matter
* when to use managed services versus self-hosted systems

### CI/CD

* build, test, scan, package, publish, deploy, verify
* artifact immutability
* promotion between environments
* rollback and approval controls

### Docker

* images, containers, layers, registries, volumes, and networking
* Dockerfile best practices
* multi-stage builds and small runtime images

### Kubernetes

* pods, deployments, services, ingress, config maps, secrets, probes
* resource requests and limits
* rollout behavior and basic troubleshooting

### IaC

* Terraform providers, modules, state, backends, and locking
* Ansible for post-provision configuration
* drift and why click-ops are risky

## Hands-On Tasks

1. Containerize a small application with a multi-stage Docker build.
2. Create a simple CI pipeline that builds, tests, and publishes an image.
3. Deploy the application to Kubernetes with health checks.
4. Provision the target environment with Terraform using a remote backend.
5. Document the release flow from commit to production.

## Checkpoint Questions

* Why should the same artifact move from staging to production?
* What is the difference between a Deployment and a StatefulSet?
* Why are Terraform state locking and remote backends important?
* When would you use a cloud load balancer versus an ingress controller?
* How do Docker layers affect build performance?

## Exit Criteria

Move to Phase 3 only when you can:

* explain an end-to-end CI/CD flow clearly
* containerize and deploy an app to Kubernetes
* explain Service, Ingress, probe, and rollout behavior
* describe Terraform state, backends, modules, and drift
* connect cloud architecture decisions to delivery and reliability