搭建一个Koa后端项目脚手架的方法步骤

├─.gitignore  // 忽略文件配置├─app.js   // 应用入口├─config.js   // 公共配置文件├─ecosystem.config.js // pm2配置文件├─package.json  // 依赖文件配置├─README.md   // README.md文档├─routes   // 路由| ├─private.js  // 校验接口| └public.js   // 公开接口├─models   // 数据库配置及模型| ├─index.js   // 数据库配置| └user.js   // 用户的schema文件├─middlewares  // 中间件| ├─cors.js  // 跨域中间件| ├─jwt.js   // jwt中间件| ├─logger.js  // 日志打印中间件| └response.js  // 响应及异常处理中间件├─logs   // 日志目录| ├─koa-template.log| └koa-template.log-2019-05-28├─lib   // 工具库| ├─error.js   // 异常处理| └mongoDB.js   // mongoDB配置├─controllers  // 操作数据库及业务逻辑| ├─index.js  // 配置| ├─login.js  // 登录| └test.js   // 测试├─bin   // 启动目录| └www    // 启动文件配置

#!/usr/bin/env node/** * Module dependencies. */const app = require('../app')const http = require('http')const config = require('../config')/** * Get port from environment and store in Express. */const port = normalizePort(process.env.PORT || config.port)// app.set('port', port);/** * Create HTTP server. */const server = http.createServer(app.callback())/** * Listen on provided port, on all network interfaces. */server.listen(port)server.on('error', onError)server.on('listening', onListening)/** * Normalize a port into a number, string, or false. */function normalizePort(val) { const port = parseInt(val, 10) if (isNaN(port)) { // named pipe return val } if (port >= 0) { // port number return port } return false}/** * Event listener for HTTP server "error" event. */function onError(error) { if (error.syscall !== 'listen') { throw error } const bind = typeof port === 'string' ? 'Pipe ' + port : 'Port ' + port // handle specific listen errors with friendly messages switch (error.code) { case 'EACCES': console.error(bind + ' requires elevated privileges') process.exit(1) break case 'EADDRINUSE': console.error(bind + ' is already in use') process.exit(1) break default: throw error }}/** * Event listener for HTTP server "listening" event. */function onListening() { const addr = server.address() const bind = typeof addr === 'string' ? 'pipe ' + addr : 'port ' + addr.port console.log('Listening on ' + bind)}

'use strict'const Koa = require('koa')const bodyParser = require('koa-bodyparser')()const staticCache = require('koa-static-cache')const config = require('./config')const publicRouter = require('./routes/public')const privateRouter = require('./routes/private')const { loggerMiddleware } = require('./middlewares/logger')const { errorHandler, responseHandler } = require('./middlewares/response')const app = new Koa()// Loggerapp.use(loggerMiddleware)// Error Handlerapp.use(errorHandler)// Global Middlewaresapp.use(bodyParser)app.use(staticCache(config.publicDir))// Routesapp.use(publicRouter.routes(), publicRouter.allowedMethods())app.use(privateRouter.routes(), privateRouter.allowedMethods())// Responseapp.use(responseHandler)module.exports = app

'use strict'const fs = require('fs')const path = require('path')const log4js = require('log4js')const config = require('../config')const logsDir = path.parse(config.logPath).dirif (!fs.existsSync(logsDir)) { fs.mkdirSync(logsDir)}log4js.configure({ appenders: { console: { type: 'console' }, dateFile: { type: 'dateFile', filename: config.logPath, pattern: '-yyyy-MM-dd' } }, categories: { default: { appenders: ['console', 'dateFile'], level: 'info' } }})const logger = log4js.getLogger('[Default]')const loggerMiddleware = async (ctx, next) => { const start = new Date() await next() const ms = new Date() - start const remoteAddress = ctx.headers['x-forwarded-for'] || ctx.ip || ctx.ips || (ctx.socket && (ctx.socket.remoteAddress || (ctx.socket.socket && ctx.socket.socket.remoteAddress))) let logText = `${ctx.method} ${ctx.status} ${ctx.url} 请求参数： ${JSON.stringify(ctx.request.body)} 响应参数： ${JSON.stringify(ctx.body)} - ${remoteAddress} - ${ms}ms` logger.info(logText)}module.exports = { logger, loggerMiddleware}

'use strict'const { logger } = require('./logger')// 这个middleware用于将ctx.result中的内容最终回传给客户端// 回传的格式遵循这样的格式：{ code: 0, msg: any data: any }const responseHandler = (ctx) => { if (ctx.result !== undefined) { ctx.type = 'json' ctx.body = { code: 200, msg: ctx.msg || '', data: ctx.result } }}// 这个middleware处理在其它middleware中出现的异常// 并将异常消息回传给客户端：{ code: '错误代码', msg: '错误信息' }const errorHandler = (ctx, next) => { return next().catch(err => { if (err.code == null) { logger.error(err.stack) } ctx.body = { code: err.code || -1, data: null, msg: err.message.trim() } ctx.status = 200 // 保证返回状态是 200, 这样前端不会抛出异常 return Promise.resolve() })}module.exports = { responseHandler, errorHandler}

'use strict'const koaJwt = require('koa-jwt')const jwt = require('jsonwebtoken')const config = require('../config')const jwtMiddleware = koaJwt({ secret: config.secret })module.exports = function (ctx, next) { // 将 token 中的数据解密后存到 ctx 中 try { if (typeof ctx.request.headers.authorization === 'string') { const token = ctx.request.headers.authorization.slice(7) ctx.jwtData = jwt.verify(token, config.secret) } else { throw {code: 401, message: 'no authorization'} } } catch (err) { throw {code: 401, message: err.message} } next()}

app.use(async (ctx, next) => { // 允许来自所有域名请求 ctx.set("Access-Control-Allow-Origin", "*"); // 这样就能只允许 http://localhost:8080 这个域名的请求了 // ctx.set("Access-Control-Allow-Origin", "http://localhost:8080");  // 设置所允许的HTTP请求方法 ctx.set("Access-Control-Allow-Methods", "OPTIONS, GET, PUT, POST, DELETE"); // 字段是必需的。它也是一个逗号分隔的字符串，表明服务器支持的所有头信息字段. ctx.set("Access-Control-Allow-Headers", "x-requested-with, accept, origin, content-type"); // 服务器收到请求以后，检查了Origin、Access-Control-Request-Method和Access-Control-Request-Headers字段以后，确认允许跨源请求，就可以做出回应。 // Content-Type表示具体请求中的媒体类型信息 ctx.set("Content-Type", "application/json;charset=utf-8"); // 该字段可选。它的值是一个布尔值，表示是否允许发送Cookie。默认情况下，Cookie不包括在CORS请求之中。 // 当设置成允许请求携带cookie时，需要保证"Access-Control-Allow-Origin"是服务器有的域名，而不能是"*"; ctx.set("Access-Control-Allow-Credentials", true); // 该字段可选，用来指定本次预检请求的有效期，单位为秒。 // 当请求方法是PUT或DELETE等特殊方法或者Content-Type字段的类型是application/json时，服务器会提前发送一次请求进行验证 // 下面的的设置只本次验证的有效时间，即在该时间段内服务端可以不用进行验证 ctx.set("Access-Control-Max-Age", 300); /* CORS请求时，XMLHttpRequest对象的getResponseHeader()方法只能拿到6个基本字段： Cache-Control、 Content-Language、 Content-Type、 Expires、 Last-Modified、 Pragma。 */ // 需要获取其他字段时，使用Access-Control-Expose-Headers， // getResponseHeader('myData')可以返回我们所需的值 //https://www.rails365.net/articles/cors-jin-jie-expose-headers-wu ctx.set("Access-Control-Expose-Headers", "myData");  await next();})

// corsapp.use(cors(corsHandler))

'use strict'const corsHandler = { origin: function (ctx) { if (ctx.url === '/test') {  // 这里可以配置不运行跨域的接口地址  return false; } return '*'; }, exposeHeaders: ['WWW-Authenticate', 'Server-Authorization'], maxAge: 5, credentials: true, allowMethods: ['GET', 'POST', 'DELETE'], allowHeaders: ['Content-Type', 'Authorization', 'Accept'],}module.exports = { corsHandler}

const helmet = require("koa-helmet")// Helmetapp.use(helmet())

'use strict'class CodedError extends Error { constructor (message = '未知错误', code = -1) { super(message) this.code = code }}module.exports = { CodedError, /** * 拒绝访问构造函数 */ ForbiddenError: class ForbiddenError extends CodedError { constructor (message = '拒绝访问') { super(message, 403) } }, /** * 无效的参数构造函数 */ InvalidQueryError: class InvalidQueryError extends CodedError { constructor (message = '无效的参数') { super(message, 400) } }}

const fs = require('fs');const path = require('path');const mongoose = require('mongoose'); //引用mongoose模块const config = require('../config')const { logger } = require('../middlewares/logger')let url = "mongodb://" + config.mongoDB.host + ":" + config.mongoDB.port + "/" + config.mongoDB.database;var mongo = mongoose.createConnection(url); //创建一个数据库连接let db = { mongoose: mongoose, mongo: mongo, models: {}};// 错误mongo.on('error', function (err) { logger.error(new Error(err));});// 开启mongo.once('open', function () { logger.info("mongo is opened");});// 整合models文件下的其他js文件fs.readdirSync(__dirname) .filter(function (file) { return (file.indexOf(".") !== 0) && (file !== "index.js"); }).forEach(function (file) { var modelFile = require(path.join(__dirname, file)); var schema = new mongoose.Schema(modelFile.schema); db.models[modelFile.name] = mongo.model(modelFile.name, schema, modelFile.name);});// 根据name选择modeldb.getModel = function (name) { return this.models[name];};module.exports = db;

fs.readdirSync(__dirname) .filter(function (file) { return (file.indexOf(".") !== 0) && (file !== "index.js"); }).forEach(function (file) { var modelFile = require(path.join(__dirname, file)); var schema = new mongoose.Schema(modelFile.schema); db.models[modelFile.name] = mongo.model(modelFile.name, schema, modelFile.name);});

'use strict'module.exports = { name: "user", schema: { uuid: String, // UUID userName: String, // 用户名 password: String, // 密码 }};

const User = require('../models/index').getModel('user')const user = await User.findOne({userName: userName})

 "scripts": { "start": "node ./bin/www", "dev": "pm2 start ecosystem.config.js --env dev", "test": "pm2 start ecosystem.config.js --env test", "pro": "pm2 start ecosystem.config.js --env pro", "logs": "pm2 logs", "stop": "pm2 stop ecosystem.config.js" },

module.exports = { apps : [{ name: 'API', script: './bin/www', // Options reference: https://pm2.io/doc/en/runtime/reference/ecosystem-file/ args: 'one two', instances: 1, autorestart: true, watch: true, ignore_watch: [    // 不用监听的文件 'node_modules', 'logs' ], max_memory_restart: '1G', env_pro: { "NODE_ENV": "production", "REMOTE_ADDR": "" }, env_dev: { "NODE_ENV": "development", "REMOTE_ADDR": "" }, env_test: { "NODE_ENV": "test", "REMOTE_ADDR": "" } }]};

// Routesapp.use(publicRouter.routes(), publicRouter.allowedMethods())app.use(privateRouter.routes(), privateRouter.allowedMethods())

'use strict'const Router = require('koa-router')const controllers = require('../controllers')const jwtMiddleware = require('../middlewares/jwt')const router = new Router()router.prefix('/api')router.use(jwtMiddleware)router.get('/test', controllers.test.test)module.exports = router

'use strict'const Router = require('koa-router')const controllers = require('../controllers')const router = new Router()router.prefix('/api')router.post('/login', controllers.login.login)module.exports = router

'use strict'const fs = require('fs')const files = fs.readdirSync(__dirname).filter(file => file !== 'index.js')const controllers = {}for (const file of files) { if (file.toLowerCase().endsWith('js')) { const controller = require(`./${file}`) controllers[`${file.replace(//.js/, '')}`] = controller }}module.exports = controllers

'use strict'const jwt = require('jsonwebtoken')const config = require('../config')const User = require('../models/index').getModel('user')const login = {}login.login = async (ctx, next) => { const {userName, password} = ctx.request.body const user = await User.findOne({userName: userName}) if (!user) { ctx.result = '' ctx.msg = '用户不存在' } else { ctx.result = jwt.sign({  data: user._id,  // 设置 token 过期时间  exp: Math.floor(Date.now() / 1000) + (60 * 60), // 60 seconds * 60 minutes = 1 hour }, config.secret) } return next()}module.exports = login

'use strict'const path = require('path')module.exports = { port: '3001', secret: 'secret', publicDir: path.resolve(__dirname, './public'), logPath: path.resolve(__dirname, './logs/koa-template.log'), mongoDB: { database: 'mall', username: 'root', password: 'root', host: '127.0.0.1', port: 27017 }}

{ "name": "koa-template", "version": "0.1.0", "author": "bayi", "private": true, "scripts": { "start": "node ./bin/www", "dev": "pm2 start ecosystem.config.js --env dev", "test": "pm2 start ecosystem.config.js --env test", "pro": "pm2 start ecosystem.config.js --env pro", "logs": "pm2 logs", "stop": "pm2 stop ecosystem.config.js" }, "dependencies": { "koa": "^2.6.2", "koa-bodyparser": "^4.2.1", "koa-helmet": "^4.1.0", "koa-jwt": "^3.5.1", "koa-router": "^7.4.0", "koa-static-cache": "^5.1.2", "koa2-cors": "^2.0.6", "log4js": "^3.0.6", "mongoose": "^5.5.5" }}