Make real-time work with web sessions in redis-cluster

services/real-time/app.coffee

@@ -1,20 +1,28 @@
+logger = require "logger-sharelatex"
+logger.initialize("real-time-sharelatex")
+
 express = require("express")
 session = require("express-session")
 redis = require("redis-sharelatex")
+ioredis = require('ioredis')
+Settings = require "settings-sharelatex"
+
+redisSessionsSettings = Settings.redis.websessions or Settings.redis.web
+
+if redisSessionsSettings?.cluster?
+	logger.log {}, "using redis cluster for web sessions"
+	rclient = new ioredis.Cluster(redisSessionsSettings.cluster)
+else
+	rclient = redis.createClient(redisSessionsSettings)
+
 RedisStore = require('connect-redis')(session)
 SessionSockets = require('session.socket.io')
 CookieParser = require("cookie-parser")
 
-Settings = require "settings-sharelatex"
-
-logger = require "logger-sharelatex"
-logger.initialize("real-time-sharelatex")
-
 Metrics = require("metrics-sharelatex")
 Metrics.initialize(Settings.appName or "real-time")
 Metrics.event_loop.monitor(logger)
 
-rclient = redis.createClient(Settings.redis.web)
 
 # Set up socket.io server
 app = express()
@@ -42,14 +50,14 @@ io.configure ->
 
 app.get "/status", (req, res, next) ->
 	res.send "real-time-sharelatex is alive"
-	
+
 redisCheck = redis.activeHealthCheckRedis(Settings.redis.web)
 app.get "/health_check/redis", (req, res, next) ->
 	if redisCheck.isAlive()
 		res.send 200
 	else
 		res.send 500
-	
+
 Router = require "./app/js/Router"
 Router.configure(app, io, sessionSockets)
 
@@ -58,13 +66,13 @@ WebsocketLoadBalancer.listenForEditorEvents(io)
 
 DocumentUpdaterController = require "./app/js/DocumentUpdaterController"
 DocumentUpdaterController.listenForUpdatesFromDocumentUpdater(io)
-	
+
 port = Settings.internal.realTime.port
 host = Settings.internal.realTime.host
 
 server.listen port, host, (error) ->
 	throw error if error?
 	logger.info "realtime starting up, listening on #{host}:#{port}"
-	
+
 # Stop huge stack traces in logs from all the socket.io parsing steps.
-Error.stackTraceLimit = 10
+Error.stackTraceLimit = 10

services/real-time/package.json

@@ -15,6 +15,7 @@
     "cookie-parser": "^1.3.3",
     "express": "^4.10.1",
     "express-session": "^1.9.1",
+    "ioredis": "^2.4.0",
     "logger-sharelatex": "git+https://github.com/sharelatex/logger-sharelatex.git#v1.1.0",
     "metrics-sharelatex": "git+https://github.com/sharelatex/metrics-sharelatex.git#v1.4.0",
     "redis-sharelatex": "0.0.9",