util.js

/*
Copyright (c) 2017 Steve Yardumian

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
'use strict'

var AWS = require('aws-sdk')
var s3 = new AWS.S3()
var AdmZip = require('adm-zip')
var fs = require('fs')
var dateTime = require('date-time')
var md5 = require('md5')
var mime = require('mime-types')

var decompress = function (/* String */command, /* Function */ cb) {
  const targetBucket = Object.prototype.hasOwnProperty.call(command, 'targetBucket') ? command.targetBucket : command.bucket
  let targetFolder = Object.prototype.hasOwnProperty.call(command, 'targetFolder') ? command.targetFolder : ''
  if (targetFolder.length > 0) targetFolder += '/'
  if (!command.bucket || !command.file) { // bucket and file are required
    if (cb) cb(new Error('Error: missing either bucket name, full filename, targetBucket or targetKey!'))
    else console.error('Error: missing either bucket name, full filename, targetBucket or targetKey!')
    return
  }

  s3.getObject({
    Bucket: command.bucket,
    Key: command.file
  }, function (err, data) {
    if (err) {
      if (cb) cb(new Error('File Error: ' + err.message))
      else console.error('File Error: ' + err.message)
    } else {
      if (command.verbose) console.log('Zip file \'' + command.file + '\' found in S3 bucket!')

      var metadata = {}
      if (command.copyMetadata) {
        metadata = data.Metadata
        console.log('zip metadata', metadata)
      }

      // write the zip file locally in a tmp dir
      var tmpZipFilename = md5(dateTime({ showMilliseconds: true }))
      fs.writeFileSync('/tmp/' + tmpZipFilename + '.zip', data.Body)

      // check that file in that location is a zip content type, otherwise throw error and exit
      if (mime.lookup('/tmp/' + tmpZipFilename + '.zip') !== 'application/zip') {
        if (cb) cb(new Error('Error: file is not of type zip. Please select a valid file (filename.zip).'))
        else console.error('Error: file is not of type zip. Please select a valid file (filename.zip).')
        fs.unlinkSync('/tmp/' + tmpZipFilename + '.zip')
        return
      }

      var zip, zipEntries, zipEntryCount
      // find all files in the zip and the count of them
      try {
        zip = new AdmZip('/tmp/' + tmpZipFilename + '.zip')
        zipEntries = zip.getEntries()
        zipEntryCount = Object.keys(zipEntries).length
      } catch (err) {
        cb(err)
      }

      // if no files found in the zip
      if (zipEntryCount === 0) {
        if (cb) cb(new Error('Error: the zip file was empty!'))
        else console.error('Error: the zip file was empty!')
        fs.unlinkSync('/tmp/' + tmpZipFilename + '.zip')
        return
      }

      // for each file in the zip, decompress and upload it to S3; once all are uploaded, delete the tmp zip and zip on S3
      var counter = 0
      zipEntries.forEach(function (zipEntry) {
        s3.upload({ Bucket: targetBucket, Key: targetFolder + zipEntry.entryName, Body: zipEntry.getData(), Metadata: metadata }, function (err, data) {
          counter++

          if (err) {
            if (cb) cb(new Error('Upload Error: ' + err.message))
            else console.error('Upload Error: ' + err.message)
            fs.unlinkSync('/tmp/' + tmpZipFilename + '.zip')
            return
          }

          if (command.verbose) console.log('File decompressed to S3: ' + data.Location)

          // if all files are unzipped...
          if (zipEntryCount === counter) {
            // delete the tmp (local) zip file
            fs.unlinkSync('/tmp/' + tmpZipFilename + '.zip')

            if (command.verbose) console.log('Local temp zip file deleted.')

            // delete the zip file up on S3
            if (command.deleteOnSuccess) {
              s3.deleteObject({ Bucket: command.bucket, Key: command.file }, function (err) {
                if (err) {
                  if (cb) cb(new Error('Delete Error: ' + err.message))
                  else console.error('Delete Error: ' + err.message)
                  return
                }

                if (command.verbose) console.log('S3 file \'' + command.file + '\' deleted.')

                // WE GOT TO THE END
                cb(null, 'Success!')
              })
            } else {
              // WE GOT TO THE END
              cb(null, 'Success!')
            }
          }
        })
      })
    }
  }
  )
}

module.exports = {
  decompress: decompress
}