Load env vars from S3

loadEnv.node8.js

const S3 = require('aws-sdk').S3;
const dotenv = require('dotenv');
const Url = require('url');
const p = require('util').promisify;
const fs = require('fs');

/**
 * @param {string} envUri
 * @returns {Promise<Object>}
 */
async function loadEnv(envUri) {
	const content = await loadFromUri(envUri);
	return dotenv.parse(content);
}

async function loadFromUri(uri) {
	const protocol = Url.parse(uri).protocol;

	if (protocol === 'file:') {
		let filePath = uri.slice('file://'.length)
		return await p(fs.readFile)(filePath, 'utf8');
	}
	if (protocol === 's3:') {
		const s3 = new S3();
		const s3Obj = parseS3Path(uri);
		const res = await s3.getObject(s3Obj).promise();
		return res.Body.toString('utf8');
	}
	throw new Error(`Unrecognized protocol: ${protocol}. Expected s3: or file:`);
}


/**
 * @param {string} s3Path
 * @returns {{Bucket: *, Key: *}}
 */
function parseS3Path(s3Path) {
	const matches = new RegExp('^s3://([^/]+)/(.+)$').exec(s3Path.trim());
	if (!matches) {
		throw new Error(`Invalid s3 path: ${s3Path}`);
	}

	return { Bucket: matches[1], Key: matches[2] };
}

module.exports = loadEnv;

loadS3Env.js

const S3 = require('aws-sdk').S3;
const dotenv = require('dotenv');
const co = require('co');

/**
 * @param {string} s3Path
 * @returns {Promise<Object>}
 */
function loadS3Env(s3Path) {
  return co(function*() {
    const s3 = new S3();

    try {
      const s3Obj = parseS3Path(s3Path);
      const res = yield cb => s3.getObject(s3Obj, cb);
      return dotenv.parse(res.Body.toString('utf8'));
    }
    catch (err) {
      throw new Error(`Failed to load env from ${s3Path}: ${err.message}`);
    }
  });
}


/**
 * @param {string} s3Path
 * @returns {{Bucket: *, Key: *}}
 */
function parseS3Path(s3Path) {
  const matches = new RegExp('^s3://([^/]+)/(.+)$').exec(s3Path.trim());
  if (!matches) {
    throw new Error(`Invalid s3 path: ${s3Path}`);
  }

  return { Bucket: matches[1], Key: matches[2] };
}

module.exports = loadS3Env;

loadS3Env.ts

import {S3} from 'aws-sdk';
const dotenv = <any>require('dotenv');

async function loadS3Env(s3Path:string):Promise<Object> {
  const s3 = new S3();

  try {
    const s3Obj = parseS3Path(s3Path);
    const res = await new Promise<any>((onRes, onErr) => {
      s3.getObject(s3Obj, (err, res) => err ? onErr(err) : onRes(res));
    });
    return dotenv.parse(res.Body.toString('utf8'));
  }
  catch (err) {
    throw new Error(`Failed to load env from ${s3Path}: ${err.message}`);
  }
}


function parseS3Path(s3Path:string):{ Bucket: string, Key: string } {
  const matches = new RegExp('^s3://([^/]+)/(.+)$').exec(s3Path.trim());
  if (!matches) {
    throw new Error(`Invalid s3 path: ${s3Path}`);
  }

  return { Bucket: matches[1], Key: matches[2] };
}

export default loadS3Env;