How to Containerize a Node.js Application with Docker and Deploy with GitHub Actions

mkdir nodejs-docker-cicd && cd nodejs-docker-cicd
npm init -y
npm install express pg dotenv
npm install --save-dev nodemon

const express = require('express');
const { Pool } = require('pg');
require('dotenv').config();

const app = express();
app.use(express.json());

const pool = new Pool({
  host: process.env.DB_HOST,
  port: process.env.DB_PORT,
  database: process.env.DB_NAME,
  user: process.env.DB_USER,
  password: process.env.DB_PASSWORD,
});

// 启动时创建表
pool.query(`
  CREATE TABLE IF NOT EXISTS tasks (
    id SERIAL PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    completed BOOLEAN DEFAULT FALSE,
    created_at TIMESTAMP DEFAULT NOW()
  )
`).catch(console.error);

// 健康检查 —— Docker HEALTHCHECK 和负载均衡器需要
app.get('/health', (req, res) => {
  res.json({ status: 'ok', timestamp: new Date().toISOString() });
});

app.get('/tasks', async (req, res) => {
  try {
    const result = await pool.query('SELECT * FROM tasks ORDER BY created_at DESC');
    res.json(result.rows);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.post('/tasks', async (req, res) => {
  const { title } = req.body;
  if (!title) return res.status(400).json({ error: 'Title is required' });
  try {
    const result = await pool.query(
      'INSERT INTO tasks (title) VALUES ($1) RETURNING *',
      [title]
    );
    res.status(201).json(result.rows[0]);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.patch('/tasks/:id', async (req, res) => {
  const { id } = req.params;
  const { completed } = req.body;
  try {
    const result = await pool.query(
      'UPDATE tasks SET completed = $1 WHERE id = $2 RETURNING *',
      [completed, id]
    );
    if (result.rows.length === 0) return res.status(404).json({ error: 'Task not found' });
    res.json(result.rows[0]);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => console.log(`Server running on port ${PORT}`));

"scripts": {
  "start": "node src/index.js",
  "dev": "nodemon src/index.js"
}

DB_HOST=localhost
DB_PORT=5432
DB_NAME=tasksdb
DB_USER=postgres
DB_PASSWORD=yourpassword
PORT=3000

# ── 第一阶段：安装依赖 ──────────────────────────────────────────
FROM node:18-alpine AS builder

WORKDIR /app

# 首先复制 package 文件——Docker 会单独缓存这一层。
# 如果仅修改源代码（不修改 package.json），Docker 重建时会跳过 npm ci。
COPY package*.json ./
RUN npm ci

COPY . .

# ── 第二阶段：生产镜像 ───────────────────────────────────────────────
FROM node:18-alpine AS production

# 创建非 root 用户——容器内以 root 身份运行存在安全风险
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nodeuser -u 1001

WORKDIR /app

COPY package*.json ./
RUN npm ci --only=production

# 仅从 builder 阶段复制源代码（不复制 node_modules 或开发文件）
COPY --from=builder /app/src ./src

RUN chown -R nodeuser:nodejs /app
USER nodeuser

EXPOSE 3000

# Docker 每 30 秒会 ping 一次 /health。如果失败 3 次，容器会被标记为不健康。
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
  CMD wget --no-verbose --tries=1 --spider http://localhost:3000/health || exit 1

CMD ["node", "src/index.js"]

node_modules
npm-debug.log
.env
.git
.gitignore
README.md
Dockerfile
.dockerignore

node_modules/
.env
.env.local
npm-debug.log*
logs/
.DS_Store
Thumbs.db
.vscode/
.idea/
dist/
build/

ERROR: Error response from daemon: Docker Desktop is unable to start

docker : The term 'docker' is not recognized as the name of a cmdlet, function,
script file, or operable program.

docker build -t nodejs-docker-cicd:latest .

[+] Building 33.1s (17/17) FINISHED
 => [builder 1/5] FROM docker.io/library/node:18-alpine       20.9s
 => [builder 4/5] RUN npm ci                                   3.5s
 => [production 5/7] RUN npm ci --only=production              3.2s
 => [production 7/7] RUN chown -R nodeuser:nodejs /app         3.2s
 => exporting to image                                         1.5s
 => => naming to docker.io/library/nodejs-docker-cicd:latest     0.0s

docker images nodejs-docker-cicd

镜像名称                  ID             磁盘使用量   内容大小
nodejs-docker-cicd:latest   c9eed311d999        198MB         47.5MB

services:
  app:
    build:
      context: .
      target: production
    ports:
      - '3000:3000'
    environment:
      DB_HOST: postgres
      DB_PORT: 5432
      DB_NAME: tasksdb
      DB_USER: postgres
      DB_PASSWORD: postgres
      PORT: 3000
    depends_on:
      postgres:
        condition: service_healthy
    restart: unless-stopped

  postgres:
    image: postgres:15-alpine
    environment:
      POSTGRES_DB: tasksdb
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
    ports:
      - '5432:5432'
    volumes:
      - postgres_data:/var/lib/postgresql/data
    healthcheck:
      test: ['CMD-SHELL', 'pg_isready -U postgres']
      interval: 5s
      timeout: 5s
      retries: 5

volumes:
  postgres_data:

docker compose up --build

curl -X POST http://localhost:3000/tasks \
  -H "Content-Type: application/json" \
  -d '{"title": "Learn Docker"}'

curl http://localhost:3000/tasks

curl http://localhost:3000/health

'{"title": "Learn Docker"}' | Set-Content body.json
curl.exe -X POST http://localhost:3000/tasks -H "Content-Type: application/json" --data `@body.json

curl.exe http://localhost:3000/tasks

curl.exe http://localhost:3000/health

# POST /tasks
{"id":1,"title":"Learn Docker","completed":false,"created_at":"2026-07-09T22:21:17.073Z"}

# GET /tasks
[{"id":1,"title":"Learn Docker","completed":false,"created_at":"2026-07-09T22:21:17.073Z"}]

# GET /health
{"status":"ok","timestamp":"2026-07-09T22:11:44.700Z"}

name: Build and Push Docker Image

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

env:
  IMAGE_NAME: ${{ secrets.DOCKERHUB_USERNAME }}/nodejs-docker-cicd

jobs:
  build-and-push:
    runs-on: ubuntu-latest

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

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Log in to Docker Hub
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.IMAGE_NAME }}
          tags: |
            type=sha,prefix=sha-
            type=raw,value=latest,enable={{is_default_branch}}

      - name: Build and push
        uses: docker/build-push-action@v5
        with:
          context: .
          target: production
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

git add .
git commit -m "Add Docker configuration and GitHub Actions workflow"
git push origin main

✅ 检出代码
✅ 配置 Docker Buildx
✅ 登录 Docker Hub
✅ 提取元数据
✅ 构建并推送

docker pull yourusername/nodejs-docker-cicd:latest
docker run -d -p 3000:3000 \
  -e DB_HOST=your-db-host \
  -e DB_NAME=tasksdb \
  -e DB_USER=postgres \
  -e DB_PASSWORD=yourpassword \
  yourusername/nodejs-docker-cicd:latest