From cb289f2decfe240ef89b080d4c09bc6e926360f8 Mon Sep 17 00:00:00 2001
From: Brian Gough <brian.gough@overleaf.com>
Date: Tue, 9 Jul 2019 11:45:00 +0100
Subject: [PATCH] make redis client list dynamic based on settings

---
 .../real-time/app/coffee/DocumentUpdaterController.coffee  | 4 ++--
 services/real-time/app/coffee/RedisClientManager.coffee    | 7 +++++++
 services/real-time/app/coffee/WebsocketLoadBalancer.coffee | 6 +++---
 3 files changed, 12 insertions(+), 5 deletions(-)
 create mode 100644 services/real-time/app/coffee/RedisClientManager.coffee

diff --git a/services/real-time/app/coffee/DocumentUpdaterController.coffee b/services/real-time/app/coffee/DocumentUpdaterController.coffee
index 41e3bb571a..0c89c7dd06 100644
--- a/services/real-time/app/coffee/DocumentUpdaterController.coffee
+++ b/services/real-time/app/coffee/DocumentUpdaterController.coffee
@@ -1,6 +1,6 @@
 logger = require "logger-sharelatex"
 settings = require 'settings-sharelatex'
-redis = require("redis-sharelatex")
+RedisClientManager = require "./RedisClientManager"
 SafeJsonParse = require "./SafeJsonParse"
 EventLogger = require "./EventLogger"
 HealthCheckManager = require "./HealthCheckManager"
@@ -11,7 +11,7 @@ MESSAGE_SIZE_LOG_LIMIT = 1024 * 1024 # 1Mb
 module.exports = DocumentUpdaterController =
 	# DocumentUpdaterController is responsible for updates that come via Redis
 	# Pub/Sub from the document updater.
-	rclientList: [redis.createClient(settings.redis.pubsub)]
+	rclientList: RedisClientManager.createClientList(settings.redis.pubsub, settings.redis.unusedpubsub)
 
 	listenForUpdatesFromDocumentUpdater: (io) ->
 		for rclient in @rclientList
diff --git a/services/real-time/app/coffee/RedisClientManager.coffee b/services/real-time/app/coffee/RedisClientManager.coffee
new file mode 100644
index 0000000000..32b10668f8
--- /dev/null
+++ b/services/real-time/app/coffee/RedisClientManager.coffee
@@ -0,0 +1,7 @@
+redis = require("redis-sharelatex")
+
+modules.export = RedisClientManager =
+    createClientList: (configs...)
+        # create a dynamic list of redis clients, excluding any configurations which are not defined
+        clientList = (redis.createClient(x) for x in configs when x?))
+        return clientList
\ No newline at end of file
diff --git a/services/real-time/app/coffee/WebsocketLoadBalancer.coffee b/services/real-time/app/coffee/WebsocketLoadBalancer.coffee
index 5c91cd9fa9..89fdc9a27a 100644
--- a/services/real-time/app/coffee/WebsocketLoadBalancer.coffee
+++ b/services/real-time/app/coffee/WebsocketLoadBalancer.coffee
@@ -1,13 +1,13 @@
 Settings = require 'settings-sharelatex'
 logger = require 'logger-sharelatex'
-redis = require("redis-sharelatex")
+RedisClientManager = require "./RedisClientManager"
 SafeJsonParse = require "./SafeJsonParse"
 EventLogger = require "./EventLogger"
 HealthCheckManager = require "./HealthCheckManager"
 
 module.exports = WebsocketLoadBalancer =
-	rclientPubList: [redis.createClient(Settings.redis.pubsub)]
-	rclientSubList: [redis.createClient(Settings.redis.pubsub)]
+	rclientPubList: RedisClientManager.createClientList(Settings.redis.pubsub, Settings.redis.unusedpubsub)
+	rclientSubList: RedisClientManager.createClientList(Settings.redis.pubsub, Settings.redis.unusedpubsub)
 
 	emitToRoom: (room_id, message, payload...) ->
 		if !room_id?