api rate limiter rough design

packages/app/src/server/middlewares/api-rate-limiter.ts

@@ -7,29 +7,76 @@ const logger = loggerFactory('growi:middleware:api-rate-limit');
 
 module.exports = (crowi, rateLimiter) => {
 
+  // API_RATE_LIMIT_010_FOO_ENDPOINT=/_api/v3/foo
+  // API_RATE_LIMIT_010_FOO_METHODS=GET,POST
+  // API_RATE_LIMIT_010_FOO_CONSUME_POINTS=100
+
   return (req: Request, res: Response, next: NextFunction) => {
 
-    // delete param from url
     const endpoint = req.url.replace(/\?.*$/, '');
     const key = req.ip + endpoint;
 
-    rateLimiter.consume(key, 2) // consume 2 points
-      .then((rateLimiterRes) => {
-        // 2 points consumed
-        logger.info(`${key}: consume 2 points!!!`);
-        next();
-      })
-      .catch((rateLimiterRes) => {
-        // Not enough points to consume
-        logger.error(`${key}: point is not enough!`);
-        next();
-      });
+    const defaultPoints = 10;
+
+    const consumePoints = (points: number = defaultPoints) => {
+      rateLimiter.consume(key, points)
+        .then((rateLimiterRes) => {
+          logger.info(`${key}: consume 2 points!!!`);
+          next();
+        })
+        .catch((rateLimiterRes) => {
+          logger.error(`${key}: point is not enough!`);
+          next();
+        });
+      next();
+    };
+
+    // pick up API_RATE_LIMIT_*_ENDPOINT from env var
+    const apiRateEndpointKeys = Object.keys(process.env).filter((key) => {
+      const endpointRegExp = /^API_RATE_LIMIT_*_ENDPOINT/;
+      return endpointRegExp.test(key);
+    });
+
+    const matchedEndpointKeys = apiRateEndpointKeys.filter((key) => {
+      return process.env[key] === endpoint;
+    });
+
+    // return default
+    if (matchedEndpointKeys.length === 0) {
+      logger.info(`endpoint: ${endpoint} => return default api limit1`);
+      consumePoints();
+    }
+
+
+    let prioritizedTarget: [string, string] | null = null; // priprity and keyword
+    matchedEndpointKeys.forEach((key) => {
+      const target = key.replace('API_RATE_LIMIT_', '').replace('_ENDPOINT', '');
+      const priority = target.split('_')[0];
+      const keyword = target.split('_')[1];
+      if (prioritizedTarget === null || Number(priority) > Number(prioritizedTarget[0])) {
+        prioritizedTarget = [priority, keyword];
+      }
+    });
+
+    if (prioritizedTarget === null) {
+      logger.info(`endpoint: ${endpoint} => return default api limit2`);
+      consumePoints();
+      return; // delete and find solution
+    }
 
+    const targetMethodsKey = `API_RATE_LIMIT_${prioritizedTarget[0]}_${prioritizedTarget[1]}_METHODS`;
+    const targetConsumePointsKey = `API_RATE_LIMIT_${prioritizedTarget[0]}_${prioritizedTarget[1]}_CONSUME_POINTS`;
 
-    // get config from env
+    const targetMethods = process.env[targetMethodsKey];
+    if (targetMethods === undefined || targetMethods.includes(req.method)) {
+      consumePoints();
+    }
 
-    // consume each point
+    const customizedConsumePoints = process.env[targetConsumePointsKey];
+    if (typeof customizedConsumePoints !== 'number') {
+      consumePoints();
+    }
 
-    // return error if point is not enough
+    consumePoints(Number(customizedConsumePoints));
   };
 };