Razzle plugin to force certain environment variables to be resolved dynamically at runtime for the nodejs bundle

razzle-plugin-node-runtime-vars.js

import _ from 'lodash';

/**
 * The passed list of environment variables will be removed from the nodejs
 * instance of webpack.DefinePlugin, so they can be resolved dynamically at
 * runtime.
 * @example
 * // Include this in the plugins array exported by razzle.config.js
 * const nodeRuntimeVarsPlugin = createRazzlePluginNodeRuntimeVars('PORT', 'HOST');
 * @param  {String} ...nodeRuntimeVars
 * @return {Function}
 */
const createRazzlePluginNodeRuntimeVars = (...nodeRuntimeVars) => (
  config,
  { target, dev },
  webpack,
) => {
  if (target !== 'node') {
    // Don't change dotenv build-time behavior for the client bundle
    return config;
  }
  const definePluginIndex = config.plugins.findIndex(
    plugin => plugin instanceof webpack.DefinePlugin && plugin.definitions,
  );
  if (typeof definePluginIndex !== 'undefined') {
    const nodeRunetimeVarsBlacklist = nodeRuntimeVars.map(
      name => `process.env.${name}`,
    );
    const filteredDefinitions = _.omitBy(
      config.plugins[definePluginIndex].definitions,
      (value, key) => nodeRunetimeVarsBlacklist.includes(key),
    );
    config.plugins[definePluginIndex] = new webpack.DefinePlugin(
      filteredDefinitions,
    );
  }
  return config;
};

export default createRazzlePluginNodeRuntimeVars;