Howto deploy #Mojolicious to @dotcloud
Saturday, September 15, 2012
The way I previously deployed was using the standard perl service, with a uWSGI frontend. The really cool thing about a perl-worker is that the mojo web application is running persistently allowing it to:
- Handle more requests in parallel
- Use WebSockets
- Allow the mojo app to do other tasks periodically
NOTE: The above is only available if you do async programming. (yes, you can do both sync/async in mojolicious)
DISCLAIMER: When reading this howto, you should already know the basics about Mojolicious and dotcloud.
So here is how I did it:
This file is the build file used by dotcloud to figure out which services to set up. Here is an example file that I use:
www: type: perl-worker config: perl_version: v5.16.x ports: www: http
The “magical” config setting here is “ports”. This allow the perl-worker to be accessible from the outside. Which port is given to you is then set in the environment.yml file created by dotcloud.
The next file to set up is supervisord.conf file which tells dotcloud which application to run. Here the file I use:
[program:cool_app] command = /home/dotcloud/current/script/dotcloud.sh
This simply tells Supervisor to execute the “command” once pushed to dotcloud. The shell script then need to start your mojo app the right way. Here is the content of “dotcloud.sh”:
#!/bin/sh export ENVIRONMENT_FILE="/home/dotcloud/environment.yml"; export MOJO_LOG_LEVEL="info"; # export environment.yml as shell variables $( perl -p -e's/:\s+/=/;s/^/export /' $ENVIRONMENT_FILE ); if [ "x$DOTCLOUD_PROJECT" = "xcool_app_test" ]; then export MOJO_LOG_LEVEL="debug"; fi exec /home/dotcloud/current/script/cool_app daemon --listen "http://*:$PORT_WWW";
The trick is to fetch the “PORT_WWW” variable from the environment.yml file and then start the “cool_app” with the correct listen port. The “if” in the middle is a trick I use to set the debug level once pushed to my test-instance. It is not required.
NOTE: Remember to make both “script/cool_app” and “script/dotcloud.sh” executable.
Pushing the app to dotcloud
After creating the files above, your directory tree should look something like this:
cool_app.conf # app config file dotcloud.yml lib/ # your mojo app Makefile.PL # build file for your mojo app public/ # mojo public files script/cool_app # executable script/dotcloud.sh # executable supervisord.conf t/ # perl unittests
NOTE: The directory structure will look different if you’re deploying a mojo lite app.
Run the commands below to create and push the app:
dotcloud create cool_app dotcloud push cool_app
After this you should see something like this in the output from “dotcloud”:
Deployment finished. Your application is available at the following URLs www: http://cool_app-username.dotcloud.com/
And then you’re done!
The downside about this is that you can’t serve your static files directly with nginx. To remove this “burden” from your mojo app, you should consider setting up cloudflare in front of your application. It’s a kick ass service for both DNS and content delivery.blog comments powered by Disqus