refactor(getCache): switch from MongoDB to Redis for caching implementation

addon/lib/getCache.js

@@ -1,5 +1,6 @@
 const cacheManager = require('cache-manager');
-const mangodbStore = require('cache-manager-mongodb');
+const redisStore = require('cache-manager-ioredis');
+const Redis = require('ioredis');
 
 const GLOBAL_KEY_PREFIX = 'tmdb-addon';
 const META_KEY_PREFIX = `${GLOBAL_KEY_PREFIX}|meta`;
@@ -8,24 +9,20 @@ const CATALOG_KEY_PREFIX = `${GLOBAL_KEY_PREFIX}|catalog`;
 const META_TTL = process.env.META_TTL || 7 * 24 * 60 * 60; // 7 day
 const CATALOG_TTL = process.env.CATALOG_TTL || 1 * 24 * 60 * 60; // 1 day
 
-const MONGO_URI = process.env.MONGODB_URI;
 const NO_CACHE = process.env.NO_CACHE || false;
+const REDIS_URL = process.env.REDIS_URL;
 
 const cache = initiateCache();
 
 function initiateCache() {
   if (NO_CACHE) {
     return null;
-  } else if (!NO_CACHE && MONGO_URI) {
+  } else if (REDIS_URL) {
+    const redisInstance = new Redis(REDIS_URL);
     return cacheManager.caching({
-      store: mangodbStore,
-      uri: MONGO_URI,
-      options: {
-        collection: 'tmdb_collection',
-        ttl: META_TTL
-      },
-      ttl: META_TTL,
-      ignoreCacheErrors: true
+      store: redisStore,
+      redisInstance: redisInstance,
+      ttl: META_TTL
     });
   } else {
     return cacheManager.caching({
@@ -50,4 +47,4 @@ function cacheWrapMeta(id, method) {
   return cacheWrap(`${META_KEY_PREFIX}:${id}`, method, { ttl: META_TTL });
 }
 
-module.exports = { cacheWrapCatalog, cacheWrapMeta };
+module.exports = { cacheWrapCatalog, cacheWrapMeta, cache };