index.js

var fs = require('fs')
var url = require('url')
var path = require('path')
var request = require('request')
var pump = require('pump')

var getGranules = require('../tasks/search-cmr/get-granules')

function readJSON (filepath) {
  return JSON.parse(fs.readFileSync(filepath, 'utf8'))
}

function writeJSON (filepath, data) {
  return fs.writeFileSync(filepath, JSON.stringify(data, null, 2))
}

var eventPath = path.join(__dirname, 'sync-granule-event.json')
var event = readJSON(eventPath)

var tiles = [
  'h20v08',
  'h20v09',
  'h20v10',
  'h21v08',
  'h21v09',
  'h21v10',
  'h22v08',
  'h22v09',
  'h22v10',
  'h19v03',
  'h19v04',
  'h20v03',
  'h20v04'
];

var options = {
  cmrUrl: 'https://cmr.earthdata.nasa.gov/',
  startDate: '2017-01-01T10:00:00Z',
  shortName: 'MOD09Q1',
  version: '006',
  page: 1,
  pageSize: 2000,
  tiles: tiles,
  limit: 10
};

var provider = 'https://e4ftl01.cr.usgs.gov'

function download (dir, filename, callback) {
  var filepath = path.join(__dirname, filename)
  var uri = provider + '/' + dir + filename

  initialDownloadRequest(uri, function (err, fileUrl) {
    if (err) return callback(err)
    else if (res.statusCode >= 400) return callback(body)

    downloadFile(fileUrl, filepath, function (err) {
      if (err) return callback(err)

      callback(null, filepath)
    })
  })
}

function initialDownloadRequest (uri, callback) {
  var options = {
    uri: uri,
    followRedirect: false
  }

  request(options, function (err, res, body) {
    if (err) return callback(err)
    else if (res.statusCode >= 400) return callback(body)

    var redirectUri = res.headers.location;
    followAuthRedirect(redirectUri, callback)
  })
}

function followAuthRedirect (redirectUri, callback) {
  var auth = new Buffer(
    process.env.EARTHDATA_USER + ':' +
    process.env.EARTHDATA_PASS
  ).toString('base64');

  var options = {
    uri: redirectUri,
    method: 'GET',
    followRedirect: false,
    jar: true,
    headers: {
      authorization: 'Basic ' + auth
    }
  }

  request(options, function (err, res, body) {
    if (err) return callback(err)
    else if (res.statusCode >= 400) return callback(body)
    callback(null, res.headers.location)
  })
}

function downloadFile (uri, filepath, callback) {
  var auth = new Buffer(
    process.env.EARTHDATA_USER + ':' +
    process.env.EARTHDATA_PASS
  ).toString('base64');

  var options = {
    uri: uri,
    method: 'GET',
    followRedirect: false,
    jar: true,
    headers: {
      authorization: 'Basic ' + auth
    }
  }

  request(options, function (err, res, body) {
    if (err) return callback(err)
    else if (res.statusCode >= 400) return callback(body)
    options.uri = res.headers.location
    return pump(request(options), fs.createWriteStream(filepath), callback)
  })
}

getGranules([], options, function (err, output) {
  if (err) return console.log('ERROR', err);
  event.payload.granules = output.granules

  var file = output.granules[0].files[0]

  download(file.path, file.name, function (err, filepath) {
    if (err) return console.log('ERROR', err);
    console.log('filepath', filepath)
  })
});