Extract files from an ignition config

unpack-config.js

const { ArgumentParser } = require('argparse')
const fs = require('fs')
const path = require('path')
const mkdirp = require('mkdirp')
const packageInfo = require('./package')

const argparser = new ArgumentParser({
  addHelp: true,
  description: 'Extract files from an ignition config',
  version: packageInfo.version
})

argparser.addArgument(['directory'], {
  help: 'The DIRECTORY to unpack into.',
  type: 'string',
  metavar: 'DIRECTORY'
})

const argv = argparser.parseArgs()

process.stdin.setEncoding('utf8')

process.stdin.on('readable', function () {
  var buffer, chunk
  buffer = ''
  while ((chunk = process.stdin.read()) !== null) {
    buffer += chunk
  }
  if (buffer !== '') {
    unpackConfig(JSON.parse(buffer))
  }
})

const unpackConfig = function (config) {
  var file, filePath, i, len, ref, results
  ref = config.storage.files
  results = []
  for (i = 0, len = ref.length; i < len; i++) {
    file = ref[i]
    filePath = file.path
    if (file.filesystem !== 'root') {
      filePath = path.join(file.filesystem, filePath)
    }
    filePath = path.join(argv.directory, filePath)
    mkdirp.sync(path.dirname(filePath))
    fs.writeFileSync(filePath, decodeURIComponent(file.contents.source.slice(6)), {
      encoding: 'utf8',
      mode: file.mode
    })
    results.push(fs.chownSync(filePath, file.user.id, file.group.id))
  }
  return results
}