将图片地址写以二进制写到文档里

var fs = require('fs');
var request = require('request');

var url = 'http://img.mukewang.com/59b4f61e0001d8ed06000338.jpg';
var write = fs.createWriteStream('./demo.jpg');

request.get(url).pipe(write);
write.on('finish', function () {
  console.log('success');
});