datensammler.js

const MongoClient = require('mongodb').MongoClient;

const _ = require('lodash')
const { parseString } = require('xml2js')
const fetch = require('node-fetch')
const moment = require('moment')

const MONGO_URL = "mongodb://XXX";
const XML_URL = "http://www.erfurt.de/sve/pls/info_v1.xml";

const parseNumbers = (str) => {
  if (!isNaN(str)) {
    str = str % 1 === 0 ? parseInt(str, 10) : parseFloat(str);
  }
  return str;
};

(async () => {
  try {
    const connection = await MongoClient.connect(MONGO_URL, {  keepAlive: true });
    const db = connection.db('heroku_83jx6qpf');

    const Parkhaeuser = db.collection('parkhaeuser');
    const Messungen = db.collection('messungen');

    const liveData = await fetch(XML_URL)
      .then(res => res.text())
      .then(body => new Promise( (res, rej) => parseString(body, { explicitArray: false, valueProcessors: [parseNumbers]}, (err, data) => err ? rej(err) : res(_.get(data, 'parkhaeuser.ph', [])  ))))

    for(let entry of liveData) {
      const { id, longname, kapazitaet } = entry;

      const timestamp = moment(entry.zeitpunkt)
      await Parkhaeuser.update({ _id: id}, { $set: { longname, kapazitaet } }, { upsert: true })

      if (timestamp.isValid()) {

        await Messungen.update({ zeitpunkt: timestamp.toDate(), parkhausId: id }, { $set: Object.assign({},
          _.pick(entry, ['oeffnungszustand','status','tendenz','belegung']),
          {
            parkhausId: id,
            zeitpunkt: timestamp.toDate()
          }
        )}, { upsert: true })
      }
    }

    connection.close();
  } catch (err) {
    console.error(err)
  }
})();