Influx DB (v 1.5.0+) Backup/Restore, Retention Policy and APIs helper

influx_helper.js

var Influx = require('influx');
var QL = require('influx-ql'); //influx query builder
var logger = require('../config/logger.js'); //winston logger
var configDB = require('../config/database.js'); //database constants configuration file
var cmd = require('node-cmd'); //to execute commands
var backup_path = __dirname + configDB.influx_backup; //path to temporary folder used to store backups files

// UTILS FUNCTIONS

function dateToNano(date){
  return (date.getTime() * 1000000).toString();
}

// InfluxDB (https://node-influx.github.io/class/src/index.js~InfluxDB.html)
// Query builder https://vicanso.github.io/influx-ql/QL.html

const influx = new Influx.InfluxDB({
  database: configDB.influx_DB,
  host: 'localhost',
  port: 8086,
  // username: configDB.influx_user,
  // password: configDB.influx_psw,
});

module.exports = {
  createDatabase: function(callback){
    influx.query(`CREATE DATABASE ${configDB.influx_DB}`).then(rows => {
      logger.info("Influx DB Database Created");
      if(callback) callback();
    }).catch(err => {
      logger.error(err);
      if(callback) callback(err);
    });
  },
  dropDatabase: function(callback){
    influx.query(`DROP DATABASE ${configDB.influx_DB}`).then(rows => {
      logger.info("Influx DB Database Dropped");
      if(callback) callback();
    }).catch(err => {
      logger.error(err);
      if(callback) callback(err);
    });
  },
  setRetentionPolicy: function(days, callback){
      var query = `ALTER RETENTION POLICY "autogen" ON "${configDB.influx_DB}" DURATION ${days == 0 ? 'INF' : days + 'd'}`;

      influx.query(query).then(rows => {
        callback(null);
      }).catch(err => {
        callback(err);
      })

   },
   getRetentionPolicy: function(callback){
      var query = "SHOW RETENTION POLICIES";

      influx.query(query).then(rows => {
        if(rows && rows.length > 0)
        callback(null, rows);
        else
        callback("Error while getting retention policy", null);
      }).catch(err => {
        callback(err, null);
      })

   },
   backupDatabase: function(start, end, callback){
    var command = `influxd backup -portable -database ${configDB.influx_DB} `;

    //add period if valid
    if(start && end)
      command += `-start ${start.toISOString()} -end ${end.toISOString()} `;

    command += './';

    var backup_name = (new Date()).toISOString();
    backup_name = backup_name.split(':').join('');
    backup_name = backup_name.split('-').join('');
    backup_name = backup_name.split('.')[0] + 'Z';

    var zip_name = `backup_${backup_name}`;
    var download_path = `${backup_path}/${zip_name}.zip`;

    //- go to backups folder
    //- backup database
    //- zip backup files

    command = `cd ${backup_path} && ${command} && zip ${zip_name} ${backup_name}*`

    cmd.get(command, function(err, data, stderr){
      if(err){
        logger.error(err);
        if(callback) callback(err);
      }else {
        logger.info('Backup correctly created and zipped');
        if(callback) callback(null, download_path);
      }
    });
  },
  clearBackupFolder: function(callback){

    cmd.get(`cd ${backup_path} && rm -f *`, function(err, data, stderr){
      if(err){
        logger.error(err);
        if(callback) callback(false)
      }else {
        if(callback) callback(true);
        logger.info('Backup folder cleared');
      }
    });
  },
  restoreBackup: function(fileName, callback){

    //- drop existing db
    //- go to backups folder
    //- unzip uploaded backup file
    //- restore backup
    //- remove backup files
    
    //NOTE: Be sure the directory contains just one backup

    command = `influx -execute 'drop database ${configDB.influx_DB}' && cd ${backup_path} && unzip ${fileName} && influxd restore -portable ./ && rm -f *`;

    cmd.get(command, function(err, data, stderr){
      if(err){
        logger.error(err);
        if(callback) callback(err)
      }else {
        if(callback) callback(null);
        logger.info('Backup restored');
      }
    });

  }
  
  //ADD HERE YOUR QUERIES

};