结合puppeteer和egg.js搭建html转pdf或png的node中间层服务。

npm init egg --type=simple

npm i generic-pool puppeteer egg-view-nunjucks

  view: {
    enable: true,
    package: ‘egg-view‘
  },
  nunjucks: {
    enable: true,
    package: ‘egg-view-nunjucks‘
  }

  // add your user config here
  const userConfig = {
    // myAppName: ‘egg‘,
    view: {
      defaultViewEngine: ‘nunjucks‘,
      defaultExtension: ‘.html‘,
      mapping: {
        ‘.html‘: ‘nunjucks‘
      }
    }
  };

const puppeteer = require(‘puppeteer‘);
const genPool = require(‘./gen-pool‘);

const pagePool = async (config, options) => {

  const browser = await puppeteer.launch(options)

  const factory = {
    create: () => {
      return browser.newPage()
        .then(instance => {
          instance.useCont = 0;
          return instance
        })
    },
    destroy: (instance) => {
      instance.close()
    },
    validate: (instance) => {
      return Promise.resolve(instance)
              .then(valid => {
                Promise.resolve(valid && (config.maxUses  config.maxUses))
              })
    }
  }

  const pool = genPool(factory, config)
  pool.closeBrowser = () => {
    return browser.close()
  }
  return pool
}

module.exports = pagePool

const genericPool = require(‘generic-pool‘);

const genPool = (factory, config) => {

  /**
   * 创建一个链接池
   */
  const pool = genericPool.createPool(factory, config)
  const genericAcquire = pool.acquire.bind(pool)

  /**
   * 消耗次数统计
   */
  pool.acquire = () => 
    genericAcquire()
      .then((instance) => {
        instance.useCont += 1;
        return instance
      })
  /**
   * 不管调用成功与否，都消耗一次实例
   */
  pool.use = fn => {
    let resource
    return pool.acquire()
      .then(res => {
        resource = res
        return resource
      })
      .then(fn)
      .then(
        (res) => {
          pool.release(resource)
          return res
        },
        (err) => {
          pool.release(resource)
          return err
        }
      )
  }

  return pool
}

module.exports = genPool

const pagePool = require(‘./page-pool‘);
const genericPool = require(‘generic-pool‘);
/**
 * 生成一个puppeteer链接池
 * @param {Object} [options] 创建池的配置
 * @param {Object} [options.poolConfig] 链接池的配置参数
 * @param {Number} [poolConfig.max = 10] 链接池的最大容量
 * @param {Number} [poolConfig.min = 2] 链接池的最小活跃量
 * @param {Boolean} [poolConfig.testOnBorrow = true] 在将 实例 提供给用户之前，池应该验证这些实例。
 * @param {Boolean} [poolConfig.autoStart = true] 启动时候是否初始化实例
 * @param {Number} [poolConfig.idleTimeoutMillis = 60*60*1000] 实例多久不使用将会被关闭（60分钟）
 * @param {Number} [poolConfig.evictionRunIntervalMillis = 3*60*1000] 多久检查一次是否在使用实例（3分钟）
 * @param {Object} [options.puppeteerConfig] puppeteer的启动参数配置
 */
const puppeteerPool = (options = { poolConifg: {}, puppeteerConfig: {} }) => {
  const config = {
    max: 10,
    min: 2,
    maxUses: 2048,
    testOnBorrow: true,
    autoStart: true,
    idleTimeoutMillis: 60 * 60 * 1000,
    evictionRunIntervalMillis: 3 * 60 * 1000,
    ...options.poolConfig
  }

  const launchOptions = {
    ignoreHTTPSErrors: true,
    headless: true,
    pipe: true,
    args: [
      // ‘--disabled-3d-apis‘,
      // ‘--block-new-web-contents‘,
      // ‘--disable-databases‘,
      ‘–disable-dev-shm-usage‘,
      // ‘--disable-component-extensions-with-background-pages‘,
      ‘–-no-sandbox‘,
      // ‘--disable-setuid-sandbox‘,
      ‘–-no-zygote‘,
      ‘–-single-process‘,
      ‘--no-first-run‘,
      ‘--disable-local-storage‘,
      // ‘--disable-media-session-api‘,
      // ‘--disable-notifications‘,
      // ‘--disable-pepper-3d‘,
      ‘--disabled-gpu‘
    ],
    ...options.puppeteerConfig
  }

  const factory = {
    create: async() => {
      const page = await pagePool(config, launchOptions)
      return Promise.resolve(page)
    },
    destroy: async (instance) => {
      if(instance.drain) {
        await instance.drain()
          .then(() => {
            instance.clear()
          })
      }
      instance.closeBrowser()
    },
    validate: (instance) => {
      return Promise.resolve(true)
    }
  }

  const pool = genericPool.createPool(factory, config)

  return pool
}

module.exports = puppeteerPool