CI/CD Concepts & Tool Landscape

# === Run Jenkins in Docker (fastest start) ===
docker run -d \
  --name jenkins \
  -p 8080:8080 \
  -p 50000:50000 \
  -v jenkins_home:/var/jenkins_home \
  jenkins/jenkins:lts-jdk17

# Jenkins UI → http://localhost:8080

# === Get the initial admin password ===
docker exec jenkins \
  cat /var/jenkins_home/secrets/initialAdminPassword
# Copy this → paste in browser Unlock page

# === Stop / Start ===
docker stop jenkins
docker start jenkins
# Data persists in 'jenkins_home' volume

# Requires Java 17+
sudo apt update
sudo apt install -y fontconfig openjdk-17-jre

# Add Jenkins repo key + source
sudo wget -O /usr/share/keyrings/jenkins-keyring.asc \
  https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key
echo "deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc]" \
  "https://pkg.jenkins.io/debian-stable binary/" \
  | sudo tee /etc/apt/sources.list.d/jenkins.list > /dev/null

sudo apt update && sudo apt install -y jenkins

# Start + enable
sudo systemctl enable --now jenkins
sudo systemctl status jenkins

# Get unlock password
sudo cat /var/lib/jenkins/secrets/initialAdminPassword

# UI → http://SERVER_IP:8080

# ── Workflow name ──────────────────────
name: CI Pipeline

# ── Triggers ───────────────────────────
on:
  push:
    branches: [ main, 'feat/**' ]
  pull_request:
    branches: [ main ]

# ── Jobs ───────────────────────────────
jobs:
  build-and-test:          # Job name
    runs-on: ubuntu-latest  # Runner (agent)

    strategy:
      matrix:
        node-version: [ 18, 20 ]  # Run on both!

    steps:
      # Step 1: Clone repo
      - uses: actions/checkout@v4

      # Step 2: Setup Node.js
      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: \${{ matrix.node-version }}
          cache: 'npm'

      # Step 3: Install dependencies
      - name: Install dependencies
        run: npm ci

      # Step 4: Lint
      - name: Lint
        run: npm run lint

      # Step 5: Run tests
      - name: Run tests
        run: npm test

      # Step 6: Upload coverage
      - name: Upload coverage
        uses: actions/upload-artifact@v4
        with:
          name: coverage-report
          path: coverage/

name: CI Pipeline

on:                           # ← TRIGGER
  push:
    branches: [ main ]

jobs:                         # ← PIPELINE
  build:                      # ← JOB (= stage)
    runs-on: ubuntu-latest  # ← AGENT

    env:                      # ← ENV VARS
      NODE_ENV: test

    steps:                    # ← STEPS
      - uses: actions/checkout@v4

      - name: Install     # ← STEP
        run: npm ci       # ← SHELL CMD

      - name: Test
        run: npm test

      - name: Build
        run: docker build -t app .

  notify:                     # ← 2nd JOB
    needs: [ build ]         # ← dependency
    if: failure()
    runs-on: ubuntu-latest
    steps:
      - run: echo "Build failed!"

name: CI

on:
  push:
    branches: [ main, 'feat/**' ]
  pull_request:
    branches: [ main ]

jobs:
  ci:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v4

      - name: Setup Node.js 20
        uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'

      - name: Install dependencies
        run: npm ci

      - name: Lint
        run: npm run lint || echo "No lint script"

      - name: Test
        run: npm test

      - name: Print success
        run: echo "✅ CI passed on $(date)"

# Push to specific branches
on:
  push:
    branches: [ main, develop ]
    paths-ignore: [ 'docs/**', '*.md' ]

# PRs targeting main
  pull_request:
    branches: [ main ]

# Scheduled: every weekday at 8am UTC
  schedule:
    - cron: '0 8 * * 1-5'

# Manual trigger with input
  workflow_dispatch:
    inputs:
      environment:
        description: 'Deploy target'
        required: true
        default: 'staging'

# On new git tag (version release)
  push:
    tags: [ 'v*.*.*' ]

# When another workflow completes
  workflow_run:
    workflows: [ "CI" ]
    types: [ completed ]

name: Workflow Name        # shown in Actions tab

on: push / pull_request    # or full object (see S18)

env:                        # workflow-level env vars
  NODE_ENV: production

defaults:
  run:
    working-directory: ./src  # default dir for run:

jobs:
  job-name:                  # alphanumeric + dash
    runs-on: ubuntu-latest
    timeout-minutes: 15    # kill if takes too long
    needs: [ other-job ]    # dependencies
    if: condition           # conditional execution
    environment: production # GitHub Environment
    concurrency:             # prevent simultaneous runs
      group: prod-deploy
      cancel-in-progress: true
    env:                     # job-level env vars
      TOKEN: \${{ secrets.TOKEN }}
    steps:
      - name: Step description
        uses: owner/action@v1  # marketplace
        with:
          param: value
      - name: Shell step
        run: echo "hello"
        continue-on-error: true # don't fail on error