feat: Add rate limiting across multiple servers via Redis (parse-comm…

…unity#8394)

package.json

@@ -53,6 +53,7 @@
     "pg-monitor": "2.0.0",
     "pg-promise": "11.3.0",
     "pluralize": "8.0.0",
+    "rate-limit-redis": "3.0.1",
     "redis": "4.0.6",
     "semver": "7.3.8",
     "subscriptions-transport-ws": "0.11.0",

spec/RateLimit.spec.js

@@ -1,3 +1,4 @@
+const RedisCacheAdapter = require('../lib/Adapters/Cache/RedisCacheAdapter').default;
 describe('rate limit', () => {
   it('can limit cloud functions', async () => {
     Parse.Cloud.define('test', () => 'Abc');
@@ -388,4 +389,33 @@ describe('rate limit', () => {
       })
     ).toBeRejectedWith(`Invalid rate limit option "path"`);
   });
+  describe_only(() => {
+    return process.env.PARSE_SERVER_TEST_CACHE === 'redis';
+  })('with RedisCache', function () {
+    it('does work with cache', async () => {
+      await reconfigureServer({
+        rateLimit: [
+          {
+            requestPath: '/classes/*',
+            requestTimeWindow: 10000,
+            requestCount: 1,
+            errorResponseMessage: 'Too many requests',
+            includeInternalRequests: true,
+            redisUrl: 'redis://localhost:6379',
+          },
+        ],
+      });
+      const obj = new Parse.Object('Test');
+      await obj.save();
+      await expectAsync(obj.save()).toBeRejectedWith(
+        new Parse.Error(Parse.Error.CONNECTION_FAILED, 'Too many requests')
+      );
+      const cache = new RedisCacheAdapter();
+      await cache.connect();
+      const value = await cache.get('rl:127.0.0.1');
+      expect(value).toEqual(2);
+      const ttl = await cache.client.ttl('rl:127.0.0.1');
+      expect(ttl).toEqual(10);
+    });
+  });
 });

src/Options/Definitions.js

@@ -557,6 +557,11 @@ module.exports.RateLimitOptions = {
     action: parsers.booleanParser,
     default: false,
   },
+  redisUrl: {
+    env: 'PARSE_SERVER_RATE_LIMIT_REDIS_URL',
+    help:
+      'Optional, the URL of the Redis server to store rate limit data. This allows to rate limit requests for multiple servers by calculating the sum of all requests across all servers. This is useful if multiple servers are processing requests behind a load balancer. For example, the limit of 10 requests is reached if each of 2 servers processed 5 requests.',
+  },
   requestCount: {
     env: 'PARSE_SERVER_RATE_LIMIT_REQUEST_COUNT',
     help:

src/Options/index.js

@@ -320,6 +320,9 @@ export interface RateLimitOptions {
   /* Optional, if `true` the rate limit will also apply to requests that are made in by Cloud Code, default is `false`. Note that a public Cloud Code function that triggers internal requests may circumvent rate limiting and be vulnerable to attacks.
   :DEFAULT: false */
   includeInternalRequests: ?boolean;
+  /* Optional, the URL of the Redis server to store rate limit data. This allows to rate limit requests for multiple servers by calculating the sum of all requests across all servers. This is useful if multiple servers are processing requests behind a load balancer. For example, the limit of 10 requests is reached if each of 2 servers processed 5 requests.
+   */
+  redisUrl: ?string;
 }
 
 export interface SecurityOptions {

src/middlewares.js

@@ -11,6 +11,8 @@ import rateLimit from 'express-rate-limit';
 import { RateLimitOptions } from './Options/Definitions';
 import pathToRegexp from 'path-to-regexp';
 import ipRangeCheck from 'ip-range-check';
+import RedisStore from 'rate-limit-redis';
+import { createClient } from 'redis';
 
 export const DEFAULT_ALLOWED_HEADERS =
   'X-Parse-Master-Key, X-Parse-REST-API-Key, X-Parse-Javascript-Key, X-Parse-Application-Id, X-Parse-Client-Version, X-Parse-Session-Token, X-Requested-With, X-Parse-Revocable-Session, X-Parse-Request-Id, Content-Type, Pragma, Cache-Control';
@@ -476,6 +478,35 @@ export const addRateLimit = (route, config) => {
   if (!config.rateLimits) {
     config.rateLimits = [];
   }
+  const redisStore = {
+    connectionPromise: Promise.resolve(),
+    store: null,
+    connected: false,
+  };
+  if (route.redisrUrl) {
+    const client = createClient({
+      url: route.redisrUrl,
+    });
+    redisStore.connectionPromise = async () => {
+      if (redisStore.connected) {
+        return;
+      }
+      try {
+        await client.connect();
+        redisStore.connected = true;
+      } catch (e) {
+        const log = config?.loggerController || defaultLogger;
+        log.error(`Could not connect to redisURL in rate limit: ${e}`);
+      }
+    };
+    redisStore.connectionPromise();
+    redisStore.store = new RedisStore({
+      sendCommand: async (...args) => {
+        await redisStore.connectionPromise();
+        return client.sendCommand(args);
+      },
+    });
+  }
   config.rateLimits.push({
     path: pathToRegexp(route.requestPath),
     handler: rateLimit({
@@ -512,6 +543,7 @@ export const addRateLimit = (route, config) => {
       keyGenerator: request => {
         return request.config.ip;
       },
+      store: redisStore.store,
     }),
   });
   Config.put(config);