From 2384eb83d935d691871e653be0e2ddba4f61ff3b Mon Sep 17 00:00:00 2001
From: Henry Oswald <henry.oswald@sharelatex.com>
Date: Thu, 28 Jun 2018 16:04:34 +0100
Subject: [PATCH] add load balance http endpoints to shut box down

---
 services/clsi/app.coffee                      | 32 ++++++++++++++-----
 services/clsi/config/settings.defaults.coffee |  9 ++++--
 2 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/services/clsi/app.coffee b/services/clsi/app.coffee
index 11981a72aa..cf01b47943 100644
--- a/services/clsi/app.coffee
+++ b/services/clsi/app.coffee
@@ -174,7 +174,11 @@ os = require "os"
 
 STATE = "up"
 
-server = net.createServer (socket) ->
+process.on "SIGHUP", ->
+	console.log "got SIGHUP event"
+	STATE = "down"
+
+loadTcpServer = net.createServer (socket) ->
 	socket.on "error", (err)->
 		if err.code == "ECONNRESET"
 			# this always comes up, we don't know why
@@ -182,7 +186,7 @@ server = net.createServer (socket) ->
 		logger.err err:err, "error with socket on load check"
 		socket.destroy()
 	
-	if STATE == "up" and Settings.load_balancer_agent.report_load
+	if STATE == "up" and Settings.internal.load_balancer_agent.report_load
 		currentLoad = os.loadavg()[0]
 
 		# staging clis's have 1 cpu core only
@@ -201,26 +205,38 @@ server = net.createServer (socket) ->
 		socket.write("#{STATE}\n", "ASCII")
 		socket.end()
 
+loadHttpServer = express()
 
+loadHttpServer.post "/state/up", (req, res, next) ->
+	STATE = "up"
+	logger.info "getting message to set server to down"
+	res.sendStatus 204
 
+loadHttpServer.post "/state/down", (req, res, next) ->
+	STATE = "down"
+	logger.info "getting message to set server to down"
+	res.sendStatus 204
 
 port = (Settings.internal?.clsi?.port or 3013)
 host = (Settings.internal?.clsi?.host or "localhost")
-load_port = Settings.internal.clsi.load_port or 3048
-
 
+load_tcp_port = Settings.internal.load_balancer_agent.load_port
+load_http_port = Settings.internal.load_balancer_agent.local_port
 
 if !module.parent # Called directly
 	app.listen port, host, (error) ->
 		logger.info "CLSI starting up, listening on #{host}:#{port}"
 
-	server.listen load_port, host, (error) ->
+	loadTcpServer.listen load_tcp_port, host, (error) ->
 		throw error if error?
-		logger.info "Load agent listening on load port #{load_port}"
+		logger.info "Load tcp agent listening on load port #{load_tcp_port}"
+
+	loadHttpServer.listen load_http_port, host, (error) ->
+		throw error if error?
+		logger.info "Load http agent listening on load port #{load_http_port}"
+
 module.exports = app
 
-
-
 setInterval () ->
 	ProjectPersistenceManager.clearExpiredProjects()
 , tenMinutes = 10 * 60 * 1000
diff --git a/services/clsi/config/settings.defaults.coffee b/services/clsi/config/settings.defaults.coffee
index da4aa82c17..a64941f866 100644
--- a/services/clsi/config/settings.defaults.coffee
+++ b/services/clsi/config/settings.defaults.coffee
@@ -20,7 +20,11 @@ module.exports =
 		clsi:
 			port: 3013
 			host: process.env["LISTEN_ADDRESS"] or "localhost"
-
+			
+		load_balancer_agent:
+			report_load:true
+			load_port: 3048
+			local_port: 3049
 	apis:
 		clsi:
 			url: "http://#{process.env['CLSI_HOST'] or 'localhost'}:3013"
@@ -29,6 +33,7 @@ module.exports =
 	project_cache_length_ms: 1000 * 60 * 60 * 24
 	parallelFileDownloads:1
 
+
 if process.env["DOCKER_RUNNER"]
 	module.exports.clsi =
 		dockerRunner: process.env["DOCKER_RUNNER"] == "true"
@@ -52,5 +57,3 @@ if process.env["DOCKER_RUNNER"]
 	module.exports.path.sandboxedCompilesHostDir = process.env["COMPILES_HOST_DIR"]
 
 	module.exports.path.synctexBinHostPath = process.env["SYNCTEX_BIN_HOST_PATH"]
-console.log "configggggg"
-console.log module.exports