store/copy TOML [env] variables inside .env file?

Good afternoon,

i currently have a FLY.toml file and an .ENV file, both of them have the same env variables, is there a way to have a single source of truth?

Kind Regards

If you’re using NodeJS you can modify the dotenv variables with your own variables, check out how this module does it:

var dotenv = require('dotenv')
var dotenvExpand = require('dotenv-expand')
// first they load the .env file
var myEnv = dotenv.config()
// and then they modified the variables in myEnv.parsed
// and overwrote process.env with the processed variables

It should be really easy to replace their “expand” function with something that loads in values from a toml file instead -

function expand (config) {
  // if ignoring process.env, use a blank object
  const environment = config.ignoreProcessEnv ? {} : process.env

  for (const configKey in config.parsed) {
    const value =, configKey) ? environment[configKey] : config.parsed[configKey]

    config.parsed[configKey] = _interpolate(value, environment, config)

  for (const processKey in config.parsed) {
    environment[processKey] = config.parsed[processKey]

  return config