feat(Redis): Adds support for Redis URL environment variable for more flexible configuration like the xapi-service. (LL-137)

.env.example

@@ -49,12 +49,18 @@ MONGODB_TEST_PATH=mongodb://localhost:27017/llv2tests
 
 #### REDIS ####
 # Redis is used for caching aggregations and can also be used as a queue driver where SQS is not available
+
+# The URL of your Redis instance e.g. redis://127.0.0.1:6379/0
+REDIS_URL=redis://127.0.0.1:6379/0
+
+# If REDIS_URL is not set, Learning Locker uses the following 3 variables.
 # The address of your Redis instance e.g. 127.0.0.1
-REDIS_HOST=127.0.0.1
+# REDIS_HOST=127.0.0.1
 # The port where your redis instance is running e.g. 6379
-REDIS_PORT=6379
+# REDIS_PORT=6379
 # Your Redis DB number e.g. 0
-REDIS_DB=0
+# REDIS_DB=0
+
 # A prefix for each key in the Redis DB e.g. DEVELOPMENT/PROD
 REDIS_PREFIX=LEARNINGLOCKER
 

lib/connections/redis.js

@@ -4,6 +4,9 @@ import defaultTo from 'lodash/defaultTo';
 
 const DEFAULT_REDIS_PORT = 6379;
 
+/**
+ * @returns {string|object} options for ioredis or sentinel
+ */
 export const getOptions = () => {
   const eventsRepo = defaultTo(process.env.EVENTS_REPO, 'redis');
   switch (eventsRepo) {
@@ -19,6 +22,9 @@ export const getOptions = () => {
       return { db, password, name, sentinels };
     }
     default: case 'redis': {
+      if (process.env.REDIS_URL) {
+        return process.env.REDIS_URL;
+      }
       const db = defaultTo(Number(process.env.REDIS_DB), 0);
       const password = process.env.REDIS_PASSWORD;
       const host = process.env.REDIS_HOST;
@@ -32,6 +38,7 @@ export const createClient = () => {
   try {
     const options = getOptions();
     logger.silly('Creating Redis client', options);
+    logger.error('Creating Redis client', options);
     return new Redis(options);
   } catch (e) {
     logger.error("Couldn't connect to redis", e);