Nightmare.js 网络抓取在服务器上不工作

Question

对于我的（开源）Node.js 项目 bundeszirkus.de I need to implement a web scraper that searches and downloads URLs. Currently, I am using Nightmare.js like this: link to full file

exports.scrape = function(cb) {
    _callback = cb
    _downloadedLinks = 0

    let nightmare = new Nightmare({ show: false })
    const url = 'https://www.bundestag.de/services/opendata'

    // we request nightmare to browse to the bundestag.de url and extract the whole inner html
    nightmare
        .goto(url)
        .wait('body')
        .evaluate(() => document.querySelector('body').innerHTML)
        .end()
        .then(response => {
            _downloadedLinks = 0
            let validLinks = extractLinks(response)
            _foundLinks = validLinks.length
            logger.info("[scraper] found " + validLinks.length + " valid links.")
            if(validLinks.length > 0){
                validLinks.forEach(href => {
                    downloadFileFromHref(BT_LINK + href)
                });
            } else {
                logger.info("[scraper] did not download any files.")
                _callback()
            }  
        }).catch(err => {
            logger.info("[scraper] did not download any files.")
            _callback()
        });

    // Extracting the links we need
    let extractLinks = html => {
        data = [];
        const $ = cheerio.load(html);
        $('.bt-link-dokument').each(function() {
            data.push(this.attribs.href);
         });
         return data.filter(checkDocumentLink)
    } 
}

当运行在我的本地计算机上时，这工作得很好。但是，当运行在我的 ubuntu 服务器 (AWS) 上安装它时似乎出现了问题。我读到这是由于我的服务器上没有可用的图形界面造成的，所以我正在尝试运行 Xvfb 它。

这是我的 ecosystem.config.js 文件。

当运行ning pm2 ls时可以看到Xvfb和我的服务器都是运行ning:

ubuntu@ip-XXX-XX-XX-XXX:~/bundeszirkus-server/current$ pm2 ls
┌─────────────────────┬────┬─────────┬──────┬───────┬────────┬─────────┬────────┬─────┬────────────┬────────┬──────────┐
│ App name            │ id │ version │ mode │ pid   │ status │ restart │ uptime │ cpu │ mem        │ user   │ watching │
├─────────────────────┼────┼─────────┼──────┼───────┼────────┼─────────┼────────┼─────┼────────────┼────────┼──────────┤
│ Xvfb                │ 1  │ N/A     │ fork │ 26063 │ online │ 6       │ 14m    │ 0%  │ 17.5 MB    │ ubuntu │ disabled │
│ bundeszirkus-server │ 0  │ 1.0.0   │ fork │ 26057 │ online │ 6       │ 14m    │ 0%  │ 246.4 MB   │ ubuntu │ disabled │
└─────────────────────┴────┴─────────┴──────┴───────┴────────┴─────────┴────────┴─────┴────────────┴────────┴──────────┘
 Use `pm2 show <id|name>` to get more details about an app

据我所知，一切似乎都已正确设置，但来自服务器的日志条目显示，没有正在下载的文件：

{"message":"Starting server!","level":"info","timestamp":"2020-01-11 11:56:38"}
{"message":"Starting initial scraping.","level":"info","timestamp":"2020-01-11 11:56:38"}
{"message":"[scraper] found 0 valid links.","level":"info","timestamp":"2020-01-11 11:56:42"}
{"message":"[scraper] did not download any files.","level":"info","timestamp":"2020-01-11 11:56:42"}
{"message":"Loading data.","level":"info","timestamp":"2020-01-11 11:56:42"}
{"message":"[loader] loading data ...","level":"info","timestamp":"2020-01-11 11:56:42"}

同时它在我的本地 (Ubuntu) 机器上运行时工作：

{"message":"Starting server!","level":"info","timestamp":"2020-01-11 12:52:47"}
{"message":"Starting initial scraping.","level":"info","timestamp":"2020-01-11 12:52:47"}
{"message":"[scraper] found 5 valid links.","level":"info","timestamp":"2020-01-11 12:52:49"}
{"message":"[scraper] downloading file: 19138-data.xml from href: http://www.bundestag.de/resource/blob/674998/86249f57e79b8308e820d6581e7e2a95/19138-data.xml","level":"info","timestamp":"2020-01-11 12:52:49"}
{"message":"[scraper] downloading file: 19136-data.xml from href: http://www.bundestag.de/resource/blob/674328/0e9d258d50d08923fe6d6ad1381bdb3f/19136-data.xml","level":"info","timestamp":"2020-01-11 12:52:49"}
{"message":"[scraper] downloading file: 19137-data.xml from href: http://www.bundestag.de/resource/blob/674730/2bc751b619488227c9267e3cbe12c4c3/19137-data.xml","level":"info","timestamp":"2020-01-11 12:52:49"}
{"message":"[scraper] downloading file: 19135-data.xml from href: http://www.bundestag.de/resource/blob/673576/147b80c74d6d681833568cfcf36f9670/19135-data.xml","level":"info","timestamp":"2020-01-11 12:52:49"}
{"message":"[scraper] downloading file: 19134-data.xml from href: http://www.bundestag.de/resource/blob/673116/982f9d0ec845b85bddd289ede4a589fd/19134-data.xml","level":"info","timestamp":"2020-01-11 12:52:49"}
{"message":"[scraper] finished downloading  all 5 files.","level":"info","timestamp":"2020-01-11 12:52:51"}
{"message":"Loading data.","level":"info","timestamp":"2020-01-11 12:52:51"}

我对如何寻找丢失的部分有点迷茫。非常感谢任何帮助！

Answer 1

执行以下操作后现在可以使用了：

将 xvfb 添加到这样的代码中：

let xvfb = new Xvfb();
try {
  xvfb.startSync();
}
catch (e) {
  console.log(e);
}
// scraping
xvfb.stopSync();

更改此行：.wait('body') 到 .wait(2000)。

Nightmare.js 网络抓取在服务器上不工作

Nightmare.js web-scraping not working on server

javascript

node.js

web-scraping

nightmare

server