NeDB_Files_ElasticSearch_Export.js

const fs = require('fs');
const logger = require('./logger');//JUST PICKUP A LOGGER LIKE THIS LOGGER HERE: https://gist.github.com/emg110/1ab0584ff59b6f216304ec68b0977f7c
const { Client } = require('@elastic/elasticsearch');
const client = new Client({ node: 'http://YOUR_ES_SERVER:ES_HTTP/S_PORT' });
const inStream = fs.createReadStream('././data/YOUR_NEDB_FILE.db');
var lineReader = require('readline').createInterface({
  input: inStream
});
async function writeToES(doc){
  await client.index({
    index: 'YOUR_ES_INDEX_NAME',
    type: '_doc',
    body: doc
  }).then(()=>{
    counter++;
    logger.info(counter+" Records has been stored in ES")
  }).catch(err=>{
    logger.error(err)
  })

}
var counter=0;
lineReader.on('line', function (line) {
  //line = line.replace(/\"/g, '"');// JUST IN CASE! YOU KNOW.
  //line = line.replace(/\//g, '');//JUST IN CASE! YOU KNOW.
  let rec = JSON.parse(line)
  //DO WHAT EVER TRANSFORM & VALIDATION YOU WANT WITH RECORD'S JSON BEFORE WRITING IT TO ES
  writeToES(rec);

});
inStream.on('end', function() {
  logger.info('ETL process has ended successfully....'+' & around '+counter+' Records have been transfered in total')
  client.indices.refresh({ index: 'YOUR_ES_INDEX' })
});