Preview arbitrary urls within a document (#5598)

plugins/iframely/server/iframely.ts

@@ -1,30 +1,35 @@
 import fetch from "fetch-with-proxy";
 import env from "@server/env";
 import { InternalError } from "@server/errors";
+import Logger from "@server/logging/Logger";
 import Redis from "@server/redis";
 
 class Iframely {
   private static apiUrl = `${env.IFRAMELY_URL}/api`;
   private static apiKey = env.IFRAMELY_API_KEY;
   private static cacheKeyPrefix = "unfurl";
+  private static defaultCacheExpiry = 86400;
 
   private static cacheKey(url: string) {
     return `${this.cacheKeyPrefix}-${url}`;
   }
 
-  private static async cache(url: string) {
-    const data = await this.fetch(url);
-
-    if (!data.error) {
+  private static async cache(url: string, response: any) {
+    // do not cache error responses
+    if (response.error) {
+      return;
+    }
+    try {
       await Redis.defaultClient.set(
         this.cacheKey(url),
-        JSON.stringify(data),
+        JSON.stringify(response),
         "EX",
-        data.cache_age
+        response.cache_age || this.defaultCacheExpiry
       );
+    } catch (err) {
+      // just log it, can skip caching and directly return response
+      Logger.error("Could not cache Iframely response", err);
     }
-
-    return data;
   }
 
   private static async fetch(url: string, type = "oembed") {
@@ -37,16 +42,33 @@ class Iframely {
   }
 
   private static async cached(url: string) {
-    const val = await Redis.defaultClient.get(this.cacheKey(url));
-    if (val) {
-      return JSON.parse(val);
+    try {
+      const val = await Redis.defaultClient.get(this.cacheKey(url));
+      if (val) {
+        return JSON.parse(val);
+      }
+    } catch (err) {
+      // just log it, response can still be obtained using the fetch call
+      Logger.error("Could not fetch cached Iframely response", err);
     }
   }
 
+  /**
+   * Fetches the preview data for the given url
+   * using Iframely oEmbed API
+   *
+   * @param url
+   * @returns Preview data for the url
+   */
   public static async get(url: string) {
     try {
       const cached = await this.cached(url);
-      return cached ? cached : this.cache(url);
+      if (cached) {
+        return cached;
+      }
+      const res = await this.fetch(url);
+      await this.cache(url, res);
+      return res;
     } catch (err) {
       throw InternalError(err);
     }