GitLab CI Pipeline - Containerize and Deploy Node.js Express Webserver Application, Publish Jest Integration Test Results via GitLab Pages; Mermaid Pipeline Flowchart

192.168.70.4 # GitLab Server
192.168.70.6 # Deployment Server, Ubuntu 22.04 with Docker platform installed

deploy-node.js-webserver
├── Dockerfile  # Multistage-Dockerfile
├── .env  # Variable for Node.js webserver port
├── .gitignore
├── .gitlab-ci.yml  # GitLab CI Pipeline
├── package.json  # Project metadata and dependencies
├── package-lock.json  # Locked dependency versions
├── public  # Static files (HTML, CSS, JS)
│   └── index.html  # Example HTML file
├── README.md
├── src  # Application source code
│   ├── app.js  # Main application
│   ├── routes
│   │   └── index.js  # Define route handlers
│   └── server.js  # Main application entry-point
└── tests
    └── app.test.js  # Integration test

### Variables
variables:
  DEPLOY_IP: "192.168.70.6"  # Deployment server IP
  DEPLOY_USER: "gitlab-deployment"  # Deployment server SSH user
  DEPLOY_PORT: 8080  # Port for the container to expose
  CONTAINER_NAME: "node.js-webserver"  # Name of the deployed container


### Stages
stages:
  - test
  - pages
  - build
  - deploy

### Run Just integration test
test:
  image: node:23-slim
  stage: test
  before_script:
    - mkdir -p just
    - npm install
  script:
    - npm test
  artifacts:
    paths:
      - test-report.html   # Correct path to the generated report
    when: always
    expire_in: 1 week


### Deploy Just integration test results to GitLab Pages
pages:
  image: node:23-slim
  stage: pages
  needs:
    # Run this job only if the 'test' job succeeds
    - test
  dependencies:
    # Use artifacts generated by the 'test' stage
    - test
  script:
    # Move the report to the 'public/' directory for GitLab Pages
    - mv test-report.html public/index.html
  artifacts:
    paths:
      # Specify the 'public/' directory to be published via GitLab Pages
      - public/

    
### Build Container Image
build_image:
  image: docker:stable
  stage: build
  needs:
    # Run this job only if the 'test' job succeeds
    - test
  services:
    - docker:dind
  variables:
    DOCKER_TLS_CERTDIR: ""
  before_script:
    # Login to GitLab Container Registry using predefined CI/CD variables
    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
  script:
    # Build the Docker image from the Dockerfile in the current directory
    - docker build --pull -t "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG" .
    # Push the built Docker image to the GitLab Container Registry
    - docker push "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
  rules: 
    # Rule: Run this job only for main branch and if the Dockerfile exists
    - if: $CI_COMMIT_BRANCH == "main"
      exists:
        - Dockerfile


### Deploy Container to Virtual Machine
deploy_container:
  stage: deploy
  image: alpine:latest
  needs:
    # Run this job only if the 'build_image' job succeeds
    - build_image
  before_script:
    # Update the package index, install the OpenSSH client for SSH connections
    - apk update && apk add openssh-client
    # If the private SSH key file ($ID_RSA) exists, set secure permissions (read/write for the owner only)
    - if [ -f "$ID_RSA" ]; then chmod og= $ID_RSA; fi
  script:
    #  SSH into the deployment server, log in to the GitLab Container registry
    - ssh -i $ID_RSA -o StrictHostKeyChecking=no $DEPLOY_USER@$DEPLOY_IP "docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY"
     # SSH into the deployment server, pull the image from the registry
    - ssh -i $ID_RSA -o StrictHostKeyChecking=no $DEPLOY_USER@$DEPLOY_IP "docker pull $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
    # SSH into the deployment server, remove the existing container (if it exists)
    - ssh -i $ID_RSA -o StrictHostKeyChecking=no $DEPLOY_USER@$DEPLOY_IP "docker container rm -f $CONTAINER_NAME || true"
    # SSH into the deployment server, run the new container
    - ssh -i $ID_RSA -o StrictHostKeyChecking=no $DEPLOY_USER@$DEPLOY_IP "docker run -d -p $DEPLOY_PORT:$DEPLOY_PORT --restart=unless-stopped --name $CONTAINER_NAME $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
  rules:
    # Rule: Run this job only for main branch
    - if: $CI_COMMIT_BRANCH == "main"

### Stage 1: Build

# Use the Node.js base image / Define as build stage
FROM node:23-slim AS build

# Set the working directory inside the container
WORKDIR /app

# Copy package.json and package-lock.json for dependency installation
COPY package*.json ./

# Install only production dependencies
RUN npm install --production

# Copy the rest of the application's source code
COPY . .



### Stage 2: Runtime

# Use the Alpine based Node.js image
FROM node:23-alpine3.20 AS runtime

# Create system user "appuser" / no PW
RUN adduser -S -D -H -h /app appuser

# Switch to "appuser"
USER appuser

# Set the working directory inside the container
WORKDIR /app

# Copy the application
COPY --from=build /app /app

# Expose the port your application listens on
EXPOSE 8080

# Run the application
ENTRYPOINT ["npm", "start"]

# Install Jest HTML Reporter package
npm install jest-html-reporter --save-dev

  "jest": {
    "reporters": [
      "default",
      [
        "./node_modules/jest-html-reporter",
        {
          "pageTitle": "Test Report"
        }
      ]
    ]
  }

  "jest": {
    "reporters": [
      "default",
      [
        "./node_modules/jest-html-reporter",
        {
          "pageTitle": "Test Report",
          "outputPath": "./path/to/test-report.html"
        }
      ]
    ]
  }

{
  "name": "example-express-webserver",
  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "test": "jest",
    "start": "node src/server.js"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "description": "",
  "dependencies": {
    "dotenv": "^16.4.5",
    "express": "^4.21.1"
  },
  "devDependencies": {
    "jest": "^29.7.0",
    "jest-html-reporter": "^3.10.2",
    "supertest": "^7.0.0"
  },
  "jest": {
    "reporters": [
      "default",
      [
        "./node_modules/jest-html-reporter",
        {
          "pageTitle": "Test Report"
        }
      ]
    ]
  }
}

// Import the Express framework for web applications
const express = require('express'); 

// Create an instance of the Express application
const app = express(); 

// Import routes
const routes = require('./routes');

// Import environment variables from .env
require('dotenv').config();

// Define the port, using an environment variable if available, or default to 80
const port = process.env.PORT || 80; 


// Use routes from "src/routes/index.js"
app.use('/', routes);


// Export the app for testing and server setup
module.exports = { app, port };

// Import the Express app instance and port configuration from app.js
const { app, port } = require('./app');

// Start the server
app.listen(port, () => console.log(`Server listening on port ${port}`));

// Import the built-in 'fs' (File System) module to work with files
const fs = require('fs');

// Import the Express framework for web applications
const express = require('express'); 

// Import the 'path' module for handling and manipulating file paths
const path = require('path'); 


// Create a router instance
const router = express.Router();

// Respond with plain text
router.get('/', (req, res) => {
  res.send('Hi there.\n');
});

// Respond with JSON
router.get('/json', (req, res) => {
  res.json({ text: 'Hi there.', numbers: [1, 2, 3] });
});

// Serve static files directly from the 'public' directory
router.use('/static', express.static(path.join(__dirname, '../../public')));

// Respond with custom 404 error for unmatched paths
router.use((req, res) => {
  res.status(404).send('Not found\n');
});


// Export the router so it can be used in other files
module.exports = router;

const request = require('supertest'); // Import Supertest to simulate HTTP requests
const { app } = require('../src/app'); // Import the app instance

describe('Basic Web Server Tests', () => {
  it('should return "Hi there." for GET /', async () => {
    const response = await request(app).get('/');
    expect(response.status).toBe(200); // Expect a 200 OK status
    expect(response.text).toBe('Hi there.\n'); // Expect the response body
  });

  it('should return JSON for GET /json', async () => {
    const response = await request(app).get('/json');
    expect(response.status).toBe(200); // Expect a 200 OK status
    expect(response.body).toEqual({ text: 'Hi there.', numbers: [1, 2, 3] }); // Expect the JSON response
  });

  it('should return 404 for an unknown route', async () => {
    const response = await request(app).get('/unknown');
    expect(response.status).toBe(404); // Expect a 404 Not Found status
    expect(response.text).toContain('Not found'); // Check the custom 404 message
  });
});

# Define webserver port
PORT=8080

<!DOCTYPE html>
<html>

<head>
	<title>jklug.work</title>
</head>

<body>
	<h1>Hi there</h1>
  <p>Some HTML content </p>
</body>

</html>

# Open the GitLab Pages test report
https://root.gitlab-pages.jklug.work/deploy-node.js-webserver/

# List running containers
docker ps

# Shell output:
CONTAINER ID   IMAGE                                                           COMMAND       CREATED          STATUS          PORTS                                       NAMES
a51b13956d89   gitlab-registry.jklug.work/root/deploy-node.js-webserver:main   "npm start"   19 minutes ago   Up 19 minutes   0.0.0.0:8080->8080/tcp, :::8080->8080/tcp   node.js-webserver

# Access the container terminal
docker exec -it a51b13956d89 sh

# List current user details
id

# Shell output:
uid=100(appuser) gid=65533(nogroup) groups=65533(nogroup)

# Curl the webserver: Simple text response
curl localhost:8080/

# Shell output:
Hi there.

# Curl the webserver: Json response (Use browser for JSON output in a readable format)
curl localhost:8080/json

# Shell output:
{"text":"Hi there.","numbers":[1,2,3]}

# Curl the webserver: Stream static content
curl localhost:8080/static/index.html

# Shell output:
<!DOCTYPE html>
<html>

<head>
        <title>jklug.work</title>
</head>

# Curl the webserver: Stream static content / Error not found
curl localhost:8080/static/djkgnsdg

# Shell output:
Not Found

# Curl the webserver: Not found response
curl localhost:8080/djkgnsdg

# Shell output:
Not Found

# Jest HTML Reporter package
https://www.npmjs.com/package/jest-html-reporter