added healthcheck

services/track-changes/app.coffee

@@ -47,6 +47,8 @@ app.post "/pack", (req, res, next) ->
 app.get "/status", (req, res, next) ->
 	res.send "track-changes is alive"
 
+app.get "/health_check",  HttpController.healthCheck
+
 app.use (error, req, res, next) ->
 	logger.error err: error, "an internal error occured"
 	res.send 500

services/track-changes/app/coffee/HealthChecker.coffee

@@ -0,0 +1,31 @@
+ObjectId = require("mongojs").ObjectId
+request = require("request")
+async = require("async")
+settings = require("settings-sharelatex")
+port = settings.internal.trackchanges.port
+logger = require "logger-sharelatex"
+
+module.exports =
+	check : (callback)->
+		project_id = ObjectId(settings.trackchanges.healthCheck.project_id)
+		url = "http://localhost:#{port}/project/#{project_id}"
+		logger.log project_id:project_id, "running health check"
+		jobs = [
+			(cb)->
+				request.post {url:"#{url}/flush", timeout:3000}, (err, res, body) ->
+					if err?
+						cb(err)
+					else if res?.statusCode != 204
+						cb("status code not 204, it's #{res.statusCode}")
+					else
+						cb()
+			(cb)->
+				request.get {url:"#{url}/updates", timeout:3000}, (err, res, body)->
+					if err?
+						cb(err)
+					else if res?.statusCode != 200
+						cb("status code not 200, it's #{res.statusCode}")
+					else
+						cb()
+		]
+		async.series jobs, callback

services/track-changes/app/coffee/HttpController.coffee

@@ -4,6 +4,7 @@ PackManager = require "./PackManager"
 RestoreManager = require "./RestoreManager"
 logger = require "logger-sharelatex"
 DocArchiveManager = require "./DocArchiveManager"
+HealthChecker = require "./HealthChecker"
 
 module.exports = HttpController =
 	flushDoc: (req, res, next = (error) ->) ->
@@ -80,4 +81,12 @@ module.exports = HttpController =
 		logger.log project_id: project_id, "unarchiving all track changes from s3"
 		DocArchiveManager.unArchiveAllDocsChanges project_id, (error) ->
 			return next(error) if error?
-			res.send 204
+			res.send 204
+
+	healthCheck: (req, res)->
+		HealthChecker.check (err)->
+			if err?
+				logger.err err:err, "error performing health check"
+				res.send 500
+			else
+				res.send 200

services/track-changes/package.json

@@ -16,7 +16,7 @@
     "logger-sharelatex": "git+https://github.com/sharelatex/logger-sharelatex.git#v1.0.0",
     "metrics-sharelatex": "git+https://github.com/sharelatex/metrics-sharelatex.git#v1.0.0",
     "request": "~2.33.0",
-    "redis-sharelatex": "~0.0.4",
+    "redis-sharelatex": "~0.0.9",
     "redis": "~0.10.1",
     "underscore": "~1.7.0",
     "mongo-uri": "^0.1.2",