sync.fiber(() => { const iam = new AWS.IAM({ apiVersion: '2010-05-08' }); let role = null; let getRoleParams = { RoleName: roleName }; try { console.log('Getting role ' + getRoleParams.RoleName + '...'); role = sync.await(iam.getRole(getRoleParams, sync.defer())); console.log(role); } catch (err) { console.error(err, err.stack) return; } if (role) { helper.modifyFiles(['./config/' + configFilename], [ { regexp: /YOUR_ROLE_ARN/g, replacement: role.Role.Arn } ]); } });