fucking get aws-sdk-js to read your aws-cli assumed role

get-aws-cli-sts.js

import aws from 'aws-sdk';
import fs from 'fs';
import ini from 'ini';
import path from 'path';

// compatibility with aws-cli
let cliCacheFolder = path.join(process.env.HOME, '.aws', 'cli', 'cache');
let awsProfile = process.env.AWS_PROFILE || process.env.AWS_DEFAULT_PROFILE;
if (awsProfile) {
  try {
    let configIni = ini.parse(fs.readFileSync(
      `${process.env.HOME}/.aws/config`,
      'utf-8'
    ));
    let awsProfileConfig = configIni[`profile ${awsProfile}`];
    if (awsProfileConfig && awsProfileConfig.role_arn) {
      let stsAssumeRoleArnPrefix = awsProfileConfig.role_arn.replace('iam', 'sts').replace(':role/', ':assumed-role/');

      let filenames = fs.readdirSync(cliCacheFolder);
      let files = filenames.map(function(filename) {
        filename = path.join(cliCacheFolder, filename);
        let stat = fs.statSync(filename);
        return {
          filename,
          mtime: new Date(stat.mtime)
        };
      }).sort(function(a, b) {
        if (a.mtime < b.mtime) {
          return 1;
        }
        if (a.mtime > b.mtime) {
          return -1;
        }
        return 0;
      });

      let awsCliCache;
      files.find(function(file) {
        try {
          let cache = JSON.parse(fs.readFileSync(file.filename));
          if (cache && cache.AssumedRoleUser && cache.AssumedRoleUser.Arn.indexOf(stsAssumeRoleArnPrefix) === 0) {
            awsCliCache = cache;
            return true;
          }
        } catch (_err) {
        }
        return false;
      });

      if (awsCliCache) {
        let sts = new aws.STS();
        aws.config.credentials = sts.credentialsFrom(awsCliCache);
      }
    }
  } catch (_err) {
  }
}