cleanup.js

const core = require('@actions/core');

/**
 * When the GitHub Actions job is done, clean up any environment variables that
 * may have been set by the configure-aws-credentials steps in the job.
 *
 * Environment variables are not intended to be shared across different jobs in
 * the same GitHub Actions workflow: GitHub Actions documentation states that
 * each job runs in a fresh instance.  However, doing our own cleanup will
 * give us additional assurance that these environment variables are not shared
 * with any other jobs.
 */

async function cleanup() {
  try {
    // The GitHub Actions toolkit does not have an option to completely unset
    // environment variables, so we overwrite the current value with an empty
    // string. The AWS CLI and AWS SDKs will behave correctly: they treat an
    // empty string value as if the environment variable does not exist.
    core.exportVariable('AWS_ACCESS_KEY_ID', '');
    core.exportVariable('AWS_SECRET_ACCESS_KEY', '');
    core.exportVariable('AWS_SESSION_TOKEN', '');
    core.exportVariable('AWS_DEFAULT_REGION', '');
    core.exportVariable('AWS_REGION', '');
  }
  catch (error) {
    core.setFailed(error.message);
  }
}

module.exports = cleanup;

/* istanbul ignore next */
if (require.main === module) {
  cleanup();
}