Tuesday, January 17, 2012

Play!ing with #WebSockets

Development Stack

Server: Play 1.2.4, WebSocket
Client: jQuery, Boostrap
Tested with: Safari 5.0.5 (on Win XP)
On: Localhost

Inspired by a Blog-Post from Lucas Jellema I have done a similar demo with Play!.

The nice thing is that it was really easy to setup and deploy into the cloud. So everyone can test the websocket app - eeehm that was my initial plan (Actually it does not work currently, see why below). Further I took the chance to get in touch with git and published the source code on github. So feel free to test and fork.



Since there are some great cloud services arosed in the past I wanted to give it a try. So here are my experiences:


Prerequisite: install heroku CLI, git client (Please google for it how to set app.  I only post the interesting stuff here)

C:\play\apps\play-push-imgsel>heroku login
C:\play\apps\play-push-imgsel>heroku create -s cedar play-push-imgsel
Creating play-push-imgsel... done, stack is cedar
http://play-push-imgsel.herokuapp.com/ | git@heroku.com:play-push-imgsel.git
Git remote heroku added

C:\play\apps\play-push-imgsel>git push heroku master
Counting objects: 46, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (40/40), done.
Writing objects: 100% (46/46), 110.54 KiB, done.
Total 46 (delta 6), reused 0 (delta 0)

-----> Heroku receiving push
-----> Play! app detected
-----> WARNING: Play! version not specified in dependencies.yml. Default version
: 1.2.4 being used....
-----> Installing Play! 1.2.4.....
-----> done
-----> Installing ivysettings.xml..... done
-----> Building Play! application...
~        _            _
~  _ __ | | __ _ _  _| |
~ | '_ \| |/ _' | || |_|
~ |  __/|_|\____|\__ (_)
~ |_|            |__/
~ play! 1.2.4, http://www.playframework.org
Building Play! application at directory ./
Resolving dependencies: .play/play dependencies ./ --forceCopy --silent -
Duser.home=/tmp/build_jxh1de2j7wc9 2>&1
:: loading settings :: file = /tmp/build_jxh1de2j7wc9/.ivy2/ivysettings.x
~ Resolving dependencies using /tmp/build_jxh1de2j7wc9/conf/dependencies.
~ No dependencies to install
~ Done!
Precompiling: .play/play precompile ./ --silent 2>&1
Listening for transport dt_socket at address: 8000
10:26:55,430 INFO  ~ Starting /tmp/build_jxh1de2j7wc9
10:26:56,387 INFO  ~ Precompiling ...
10:27:03,224 INFO  ~ Done.
-----> No Procfile found. Will use the following default process:
play run --http.port=$PORT $PLAY_OPTS
-----> Discovering process types
Procfile declares types -> (none)
Default types for Play! -> web
-----> Compiled slug size is 26.6MB
-----> Launching... done, v5
http://play-push-imgsel.herokuapp.com deployed to Heroku

To git@heroku.com:play-push-imgsel.git
* [new branch]      master -> master

C:\play\apps\play-push-imgsel>heroku open
Opening http://play-push-imgsel.herokuapp.com/


This is an awesome and easy to use stack!!!!! #PGH => Play, Git, Heroku!

Deployed at: http://play-push-imgsel.herokuapp.com/

Application is accessible but WS request are not working (oops).

C:\play\apps\play-push-imgsel>heroku logs
2012-01-14T10:36:29+00:00 heroku[router]: Error H12 (Request timeout) -> GET pla
y-push-imgsel.herokuapp.com/ap... dyno=web.1 queue= wai
t= service=30000ms status=503 bytes=0

=> Feature Request has been filed at Heroku. http://support.heroku.com/tickets/40910


Since WebSocket is currently not supported (according to: http://www.jamesward.com/2011/12/11/tutorial-play-framework-jpa-json-jquery-heroku) I decided to give cloudbees a try. Same here

Deployed at: http://play-push-imgsel.multikoop.cloudbees.net/

Same issues here:

... 20:27:42,952 WARN ~ 404 -> GET /application/pushimgsel/process (GET /application/pushimgsel/process) ...

=> Request #2383 "HTTP 404 on WebSocket Reque..." created. https://cloudbees.zendesk.com/tickets/2383


The cloud is not ready for WebSocket applications in early 2012! ;-)

If you want to see the demo live, all you need to do is

-Install Play 1.2.4

-Get push-imgsel Sourcecode: https://github.com/multikoop/play-push-imgsel

-Test with Safari (Other modern browsers currently not working, cause WebSocket Implementation in Play 1.2.4 cannot handle the newest Sec-WebSocket-Version Headers. Hopefully it will be fixed in 1.2.5 at least in 2.0.

Have fun!


  1. I have had the exact same experience with heroku and playapps.net.
    Just rewrote my backend to make it work for google app engine just to find out that play arcitecture doesn't work with googles channel api.. So my conclusion is also that it is more or less impossible to try websockets in the cloud at the moment.

  2. Hello Harald,

    thanks for confirming and evaluating on playapps.net and google app engine.

  3. For the websockets support, you could take a look at dotCloud, I successfully managed to deploy my play app on this platform (take a look at the end of this article : http://www.ekito.fr/portail/playing-2-0-with-twitter-bootstrap-websockets-akka-and-openlayers?lang=en)