version: 1
id: kubernetes-yaml-basics
title: Author a First Kubernetes Manifest
summary: Write a valid Deployment YAML for a simple web workload using 90Days Kubernetes fundamentals.
difficulty: beginner
estimatedMinutes: 30
prerequisites: [docker-tagging-basics]
image: alpine:3.21
shell: /bin/sh
setup:
  - "mkdir -p /workspace/k8s"
tasks:
  - id: write-deployment
    title: Describe the desired state
    description: 'Create /workspace/k8s/web.yaml defining a Deployment named web with labels app=web, one replica, and container image nginx:1.27-alpine exposing containerPort 80. Also write /workspace/k8s/README.md stating that kubectl apply makes desired state concrete.'
    hints:
      - 'kind must be Deployment under apiVersion apps/v1'
      - selector.matchLabels and template labels should both use app=web
      - README should mention kubectl apply.
    checks:
      - type: file
        name: Deployment kind
        path: /workspace/k8s/web.yaml
        value: "kind: Deployment"
      - type: file
        name: Named web
        path: /workspace/k8s/web.yaml
        value: "name: web"
      - type: file
        name: App label
        path: /workspace/k8s/web.yaml
        value: "app: web"
      - type: file
        name: Pinned nginx image
        path: /workspace/k8s/web.yaml
        value: "nginx:1.27-alpine"
      - type: file
        name: Container port
        path: /workspace/k8s/web.yaml
        value: "containerPort: 80"
      - type: file
        name: README explains apply
        path: /workspace/k8s/README.md
        value: kubectl apply
limits: {cpus: "0.5", memory: 128m, pids: 64, timeout: 1800, network: false}
attribution: "Adapted from 90DaysOfDevOps Kubernetes fundamentals (Michael Cade, CC BY-NC-SA 4.0). Rewritten as an interactive PlatformForge scenario."