loader.js

var dotenv = require("dotenv"),
    path = require('path'),
    os = require('os'),
    fs = require('fs'),
    childProcess = require('child_process'),
    execFile = childProcess.execFile,
    execFileSync = childProcess.execFileSync

var ENVKEY_FETCH_VERSION = "1.2.9"

function pickPermitted(vars, opts){
  if (opts && opts.permitted && opts.permitted.length){
    var res = {}
    for (k in vars){
      if (opts.permitted.indexOf(k) != -1){
        res[k] = vars[k]
      }
    }
    return res
  } else {
    return vars
  }
}

function applyVarsToEnv(vars){
  var varsSet = {}
  for (k in vars){
    if(!process.env.hasOwnProperty(k)){
      var val = vars[k]
      process.env[k] = val
      varsSet[k] = val
    }
  }

  return varsSet
}

function getKey(opts){
  if (opts.dotEnvFile){
    var path = opts.dotEnvFile;

    if(path.charAt(0) !== "/") {
      path = "./" + opts.dotEnvFile;
    }

    dotenv.load({path: path})
  } else {
    dotenv.config()
  }

  return process.env.ENVKEY
}

function keyError(){
  return "ENVKEY invalid. Couldn't load vars."
}

function missingKeyError(){
  return "ENVKEY missing - must be set as an environment variable or in a gitignored .env file in the root of your project. Go to https://www.envkey.com if you don't know what an ENVKEY is."
}

function throwMissingKeyError(){
  var err = missingKeyError()
  throw err
}

function throwKeyError(){
  var err = keyError()
  throw err
}

function load(optsOrCb, maybeCb){
  var opts = typeof optsOrCb == "object" ? optsOrCb : {},
      cb = typeof optsOrCb == "function" ? optsOrCb : maybeCb,
      key;

  try {
    key = getKey(opts)
  } catch (err){
    if (cb){
      cb(err)
    } else {
      throw(err)
    }
  }

  if (key){
    if (cb){
      fetch(key, opts, function(err, vars){
        if(err){
          cb(err)
        } else {
          cb(null, applyVarsToEnv(vars))
        }
      })
    } else {
      return applyVarsToEnv(fetch(key, opts))
    }
  } else if (cb){
    cb(missingKeyError())
  } else {
    throw missingKeyError()
  }
}

function fetch(keyOrCbOrOpts, optsOrCb, maybeCb){
  var key, opts, cb

  if (typeof keyOrCbOrOpts == "object"){
    opts = keyOrCbOrOpts
  } else if (typeof optsOrCb == "object"){
    opts = optsOrCb
  } else {
    opts = {}
  }

  if (typeof keyOrCbOrOpts == "function"){
    cb = keyOrCbOrOpts
  } else if (typeof optsOrCb == "function"){
    cb = optsOrCb
  } else {
    cb = maybeCb
  }

  try {
    key = typeof keyOrCbOrOpts == "string" ? keyOrCbOrOpts : getKey(opts)
  } catch (err){
    if (cb){
      cb(err)
    } else {
      throw(err)
    }
  }

  if(!key && cb){
    return cb(null, {})
  } else if (!key){
    return {}
  }

  var platform = os.platform(),
      arch = os.arch(),
      platformPart,
      archPart

  switch (platform){
    case 'darwin':
    case 'linux':
      platformPart = platform
      break
    case 'freebsd':
    case 'openbsd':
      platformPart = "freebsd"
      break
    case 'win32':
      platformPart = "windows"
      break
    default:
      platformPart = "linux"
  }

  switch (arch){
    case 'ia32':
    case 'x32':
    case 'x86':
    case 'mips':
    case 'mipsel':
    case 'ppc':
    case 's390':
      archPart = "386"
      break
    case 'x64':
    case 'ppc64':
    case 's390x':
      archPart = "amd64"
      break
    case 'arm64':
    case 'aarch64':
      archPart = "arm64"
      break
    default:
      archPart = "amd64"
  }

  if (archPart == "386"){
    throw new Error("As of 1.3.0, envkey-node only supports 64-bit systems. Please use an earlier version for 32-bit support.")
  }


  var isDev = false
  if (!process.env.NODE_ENV){
    var dotenvPath = path.resolve(process.cwd(), '.env')
    isDev = fs.existsSync(dotenvPath)
  } else if (["development", "test"].indexOf(process.env.NODE_ENV) > -1){
    isDev = true
  }

  var ext = platformPart == "windows" ? ".exe" : "",
      filePath = path.join(__dirname, "ext", ["envkey-fetch", ENVKEY_FETCH_VERSION, platformPart, archPart].join("_"), ("envkey-fetch" + ext)),
      execArgs = [key, (isDev ? "--cache" : ""), "--client-name", "envkey-node", "--client-version", "1.3.0"]

  if (cb){
    execFile(filePath, execArgs, function(err, stdoutStr, stderrStr){
      if (err){
        cb(stderrStr)
      } else if (stdoutStr.indexOf("error: ") == 0){
        cb(stdoutStr)
      } else {
        var json = JSON.parse(stdoutStr)
        cb(null, pickPermitted(json, opts))
      }
    })

  } else {
    try {
      var res = execFileSync(filePath, execArgs).toString()

      if(!res || !res.trim()){
        throwKeyError()
      }

      var json = JSON.parse(res.toString())

      if(!json){
        throwKeyError()
      }

      return pickPermitted(json, opts)
    } catch (e){
      if (e.stderr){
        console.error(e.stderr.toString())
        throw(e.stderr.toString())
      } else {
        console.error(e.stack)
        throw(e)
      }
    }
  }
}

module.exports = { load: load, fetch: fetch}