Deploying Tweeter Keeper on the Heroku Cedar Stack

To go along with my talk at the Lone Star Ruby Conference on Consuming the Twitter Streaming API with Ruby and MongoDB, I’m going to provide some deployment instructions for how to take the Tweeter Keeper ruby script and deploy it on Heroku.

Heroku provides a managed platform to run Ruby applications (not just Rails), which we can use to run Tweeter Keeper “in the cloud”. Currently, you can run one process on Heroku for free, and you can get a free MongoLab account through Heroku as well if you want to experiment with the Twitter Streaming API.

Your first step will be to sign up with Heroku and create an account on their web site.

Make sure you have Ruby 1.9.2 - the easiest way to do this is to set up RVM, if you haven’t already.

Next, go ahead and install the Heroku gem so you can interact with the Heroku platform from your command line.

Tweeter Keeper has Gemfile and Gemfile.lock setup already for Bundler, so you should be able to run bundle install from your command line, and then bundle exec ruby tweeter-keeper.rb to run the app. Be sure to set up config.yaml with a valid Twitter account’s username and password.

Tweeter Keeper isn’t a web process - it’s a command line tool that you run with bundle exec. Heroku’s Cedar Stack has support for specifying processes within your Procfile that your application can execute. Here’s the Procfile for Tweeter Keeper (just one line):

tweeterkeeper: bundle exec ruby tweeter-keeper.rb

If you need to run multiple processes (for instance, a companion web application in Sinatra or Rails), add it to the Procfile.

We’re going to use the Cedar Stack from Heroku - this isn’t currently the default, so you’ll need to specify it when you create an application on Heroku. Heroku’s Cedar Stack relies on bundler, so make sure everything’s working ok on your local development environment first.

heroku create --stack cedar

Heroku will create a new application for you, with a crazy name (that you can easily rename).

You’ll need to configure a MongoDB add-on service from the Heroku add-ons - I used MongoLab, but you can also use MongoHQ.

heroku addons:add mongolab:starter

You use git to push your code to Heroku - add your Heroku git repo as a remote:

git remote add heroku

And then go ahead and push your code out!

git push heroku master

Now see if your process is running on Heroku:

heroku ps

You should see something similar to:

Process       State               Command
------------ ------------------ ------------------------------
tweeterkeeper.1  up for 9h           bundle exec ruby tweeter-keeper.rb

To see if your tweeter keeper process is keeping tweets, go into the add-ons section for your project, pick MongoLab, and select your MongoDB collection - it should be filled with Tweets!