Script to set up AWS environment according to its profile.

getAWS.js

'use strict';

const AWS = require('aws-sdk');

let profile = process.env.LAMBDA_TASK_ROOT && process.env.AWS_EXECUTION_ENV ? '' : 'default';

const profileIndex = process.argv.indexOf('--profile');
if (profileIndex > 0 && profileIndex + 1 < process.argv.length) {
  profile = process.argv[profileIndex + 1];
}

if (profile) {
  const iniLoader = new AWS.IniLoader();
  try {
    const config = iniLoader.loadFrom({isConfig: true});
    if (config[profile]) {
      AWS.config.update(config[profile]);
    } else if (config.default && profile !== 'default') {
      console.log(`Warning: there is no configuration corresponding to profile "${profile}" --- trying the default...`);
      AWS.config.update(config.default);
    } else {
      console.log('Warning: there is no default configuration --- ignoring...');
    }
  } catch (e) {
    console.log('Warning: there is no default config file --- ignoring...');
  }
  let tryDefault = profile === 'default';
  if (!tryDefault) {
    try {
      AWS.config.credentials = new AWS.SharedIniFileCredentials({profile});
    } catch (e) {
      console.log(`Warning: there are no credentials corresponding to profile "${profile}" --- trying the default...`);
      tryDefault = true;
    }
  }
  if (tryDefault) {
    try {
      AWS.config.credentials = new AWS.SharedIniFileCredentials({profile: 'default'});
    } catch (e) {
      console.log('Warning: there are no default credentials --- ignoring...');
      tryDefault = true;
    }
  }
}

module.exports = AWS;

getOptions.js

'use strict';

const getOptions = async (AWS, {profile, warn} = {}) => {
  profile = profile || process.env.AWS_PROFILE;
  if (!profile) return {};

  let region = '',
    credentials;
  const iniLoader = new AWS.IniLoader();
  try {
    const config = iniLoader.loadFrom({isConfig: true});
    if (config[profile]) {
      region = config[profile].region;
    } else if (config.default && profile !== 'default') {
      warn && console.log(`Warning: there is no configuration corresponding to profile "${profile}" --- trying the default...`);
      region = config.default.region;
    } else {
      warn && console.log('Warning: there is no default configuration --- ignoring...');
    }
  } catch (e) {
    warn && console.log('Warning: there is no default config file --- ignoring...');
  }

  const providers = [
    () => new AWS.EnvironmentCredentials('AWS'),
    () => new AWS.EnvironmentCredentials('AMAZON'),
    () => new AWS.SharedIniFileCredentials({profile})
  ];
  if (profile !== 'default') providers.push(() => new AWS.SharedIniFileCredentials({profile: 'default'}));
  if (AWS.ECSCredentials) providers.push(() => new AWS.ECSCredentials());
  providers.push([
    () => new AWS.RemoteCredentials(),
    () => new AWS.ProcessCredentials(),
    () => new AWS.TokenFileWebIdentityCredentials(),
    () => new AWS.EC2MetadataCredentials()
  ]);

  const chain = new AWS.CredentialProviderChain(providers);
  try {
    credentials = await chain.resolvePromise();
  } catch (e) {
    warn && console.log(`Warning: no credentials corresponding to profile "${profile}" were retrieved.`);
  }

  const options = {};
  if (region) options.region = region;
  if (credentials) options.credentials = credentials;
  return options;
};

module.exports = getOptions;

This script looks for --profile XXX on the command line (optionally) and sets up the AWS object accordingly. In case of errors, it tries to load the default profile.

This file is meant to be used with command-line utilities and uses standard AWS configuration files: credentials and config.