serverless-tag-resources/src/aws-clients.js

Datamart: Tag all AWS resources with dual legacy + datamart:* tag support

"use strict";

/**
 * AWS SDK v3 client factory.
 * Lazily creates and caches clients per service+region.
 */

const clientCache = new Map();

/**
 * Get or create an AWS SDK v3 client.
 *
 * @param {Function} ClientClass - SDK v3 client constructor (e.g. CloudFormationClient)
 * @param {object} config - { region, credentials }
 * @returns {object} cached client instance
 */
function getClient(ClientClass, config) {
  const key = `${ClientClass.name}:${config.region}`;
  if (!clientCache.has(key)) {
    clientCache.set(key, new ClientClass(config));
  }
  return clientCache.get(key);
}

/**
 * Clear client cache (useful for testing).
 */
function clearClients() {
  clientCache.clear();
}

/**
 * Extract SDK v3 compatible config from Serverless provider.
 *
 * @param {object} awsProvider - serverless.getProvider('aws')
 * @returns {object} { region, credentials }
 */
function configFromProvider(awsProvider) {
  const region = awsProvider.getRegion();
  const creds = awsProvider.getCredentials();

  // Serverless v3 provides credentials in different formats
  // depending on the provider. Normalize for SDK v3.
  const config = { region };

  if (creds.credentials) {
    config.credentials = creds.credentials;
  } else if (creds.accessKeyId) {
    config.credentials = {
      accessKeyId: creds.accessKeyId,
      secretAccessKey: creds.secretAccessKey,
      sessionToken: creds.sessionToken,
    };
  }

  return config;
}

module.exports = { getClient, clearClients, configFromProvider };