From 4b25ae43b769543dc9cb4c1c43178f9d43eb095f Mon Sep 17 00:00:00 2001
From: Jason Woofenden <jason@jasonwoof.com>
Date: Wed, 13 Feb 2013 12:04:33 -0500
Subject: [PATCH] seamless upgrades, logging works async

---
 client.coffee |   91 ++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 80 insertions(+), 11 deletions(-)

diff --git a/client.coffee b/client.coffee
index 6a8d477..9e28b9b 100755
--- a/client.coffee
+++ b/client.coffee
@@ -16,13 +16,79 @@ commands = {}
 for k, v of af
 	commands[k] = v unless k is 'login'
 
-# this is the friendly one that updates the files then restarts the app
+# this is the simple one that updates the files then restarts the app.
+# to update without severing current connections or downtime, see app_publish_seamless
 commands.app_publish = (token, app_name, zip_file, callback) ->
 	async.waterfall [
 		(callback) =>      @api 'app_update_files', app_name, zip_file, callback
 		(res, callback) => @api 'app_restart',      app_name, callback
 	], callback
 
+
+# This uses a pair of apps to get a seamless upgrades. ie the site is never
+# down, and connections that are open at the time of upgrade are given 10
+# seconds to close.
+#
+# Requirements:
+#
+# 1.	There must be two apps with the same name except one has an underscore at
+#	the end and the other doesn't.
+#
+# 2.	One of these apps must be running, and must have the domain names mapped
+#	to it.
+#
+# 3.	The other must be stopped, and must not have the domain names mapped  to
+#	it. (just it's *.af.com address.)
+#
+# For now, pass only the name of the app which is currently stopped.
+commands.app_publish_seamless = (token, app_name, zip_file, callback) ->
+	# FIXME auto-detect which one is new by checking app_info.urls.length
+	# (should happen for all api calls?)
+	#
+	# for now, we assume that the passed app_name is the currently dormant one
+	if app_name.substr(-1) is '_'
+		old_app = app_name.substr 0, app_name.length - 1
+		new_app = app_name
+	else
+		old_app = app_name + '_'
+		new_app = app_name
+
+	async.auto {
+		push: (cb) => @api 'app_update_files', new_app, zip_file, cb
+		# TODO find out if app_update_files increments app_info.version
+		# if not, drop new_info's dependency on push
+		old_info: (cb) => @api 'app_info', old_app, cb
+		new_info: ['push', (cb) => @api 'app_info', new_app, cb ]
+		start_new: ['push', 'old_info', 'new_info', (cb, args) =>
+			args.new_info.state = 'STARTED'
+			for u in args.old_info.uris
+				args.new_info.uris.push u unless u.substr(-6) is '.af.cm'
+			@api 'app_set_info', new_app, args.new_info, cb
+		]
+		hide_old: ['start_new', 'old_info', (cb, args) =>
+			just_af = []
+			for u in args.old_info.uris
+				just_af.push u if u.substr(-6) is '.af.cm'
+			args.old_info.uris = just_af
+			@api 'app_set_info', old_app, args.old_info, cb
+		]
+		wait_for_old_connections: ['hide_old', (cb) =>
+			seconds = 10
+			log_id = @log_start "waiting #{seconds} seconds for connections to old instance to finish"
+			timeout seconds * 1000, =>
+				@log_end(log_id)
+				cb()
+		]
+		old_info_again: ['hide_old', (cb) =>
+			@api 'app_info', old_app, cb
+		]
+		stop_old: ['wait_for_old_connections', 'old_info_again', (cb, args) =>
+			args.old_info_again.state = 'STOPPED'
+			@api 'app_set_info', old_app, args.old_info_again, cb
+		]
+		# TODO when we get into sending manifests, we may need to update_files to old_app too
+	}, callback
+
 app_set_state = (token, app_name, state, callback) ->
 	async.waterfall [
 		(callback) =>
@@ -54,7 +120,8 @@ class Session
 		@token = 0
 		@verbose = true
 		@log_nest = 0
-		@log_mid = false
+		@log_mid = 0
+		@log_id = 0
 
 	log_whitespace: ->
 		out = ''
@@ -65,18 +132,20 @@ class Session
 
 	log_start: (msg) ->
 		return unless @verbose
-		process.stdout.write "#{@log_whitespace()}#{msg}"
+		@log_id += 1
+		process.stdout.write "#{@log_whitespace()}#{@log_id}: #{msg}"
 		@log_nest += 1
-		@log_mid = true
+		@log_mid = @log_id
+		return @log_id
 
-	log_end: ->
+	log_end: (start_id) ->
 		return unless @verbose
 		@log_nest -= 1
-		if @log_mid
+		if @log_mid is start_id
 			process.stdout.write "... done\n"
 		else
-			process.stdout.write "#{@log_whitespace()}done\n"
-		@log_mid = false
+			process.stdout.write "#{@log_whitespace()}#{start_id} done\n"
+		@log_mid = 0
 
 	api: (call, args..., callback) ->
 		async.waterfall [
@@ -90,10 +159,10 @@ class Session
 						callback null, @token
 			(token, callback) =>
 				@token = token
-				@log_start [call, args...].join ' '
+				log_id = @log_start [call, args...].join ' '
 				# commands implemented in client.coffee need "this" pointing to the session
 				commands[call].call this, @token, args..., (err, the_rest...) =>
-					@log_end() unless err?
+					@log_end(log_id) unless err?
 					callback err, the_rest...
 		], (err, result) =>
 			# eg /app/xxx/stats sometimes returns 404 with wrong auth token
@@ -113,7 +182,7 @@ class Session
 				process.stdout.write new Buffer [27, 91, 65, 27, 91, 50, 75]
 				process.stdout.write @log_whitespace() + opts.prompt + "***\n"
 			process.stdin.pause()
-			@log_mid = false
+			@log_mid = 0
 			callback null, (line.substr 0, line.length - 1)
 
 get_token = (callback) ->
-- 
1.7.10.4