server/proxy_config.js

import { memoize, values } from 'lodash'
import { format as formatUrl } from 'url'
import { Agent as HttpsAgent } from 'https'
import { readFileSync } from 'fs'

import { WildcardMatcher } from './wildcard_matcher'

const makeHttpsAgent = memoize(
  opts => new HttpsAgent(opts),
  opts => JSON.stringify(opts)
)

export class ProxyConfig {
  constructor(config) {
    config = Object.assign({}, config);

    // -----
    // read "match" info
    // -----
    const rawMatches = Object.assign({}, config.match);
    this.id = formatUrl({
      protocol: rawMatches.protocol,
      hostname: rawMatches.host,
      port: rawMatches.port,
      pathname: rawMatches.path
    }) || '*';

    this.matchers = {
      protocol: new WildcardMatcher(rawMatches.protocol),
      host: new WildcardMatcher(rawMatches.host),
      port: new WildcardMatcher(rawMatches.port),
      path: new WildcardMatcher(rawMatches.path, '/'),
    };

    // -----
    // read config vars
    // -----
    this.timeout = config.timeout;
    this.sslAgent = this._makeSslAgent(config);
  }

  _makeSslAgent(config) {
    const ssl = config.ssl || {};
    this.verifySsl = ssl.verify;

    const sslAgentOpts = {
      ca: ssl.ca && ssl.ca.map(ca => readFileSync(ca)),
      cert: ssl.cert && readFileSync(ssl.cert),
      key: ssl.key && readFileSync(ssl.key),
    };

    if (values(sslAgentOpts).filter(Boolean).length) {
      return new HttpsAgent(sslAgentOpts);
    }
  }

  getForParsedUri({ protocol, hostname, port, pathname }) {
    let match = this.matchers.protocol.match(protocol.slice(0, -1));
    match = match && this.matchers.host.match(hostname);
    match = match && this.matchers.port.match(port);
    match = match && this.matchers.path.match(pathname);

    if (!match) return {};
    return {
      timeout: this.timeout,
      rejectUnauthorized: this.sslAgent ? true : this.verifySsl,
      agent: protocol === 'https:' ? this.sslAgent : undefined
    };
  }
}