Using Mongoid, MongoHQ, and Heroku

I recently tried to set up mongoid with a free mongohq account on heroku... This info is accurate as of 28 Feb, 2012.

For the impatient (I just want to make it work)

mongoid.yml

production:
  uri: <%= ENV['MONGOLAB_URI'] %>

Gemfile

gem 'bson', '1.3.1'
gem 'bson_ext', '1.3.1'
gem 'mongoid', '2.0.2'

For those who want more detail (I have a similar problem, how do I troubleshoot

To determine heroku environment variables, do this:

$ heroku config

and the results should contain a line like what follows:
...
MONGOLAB_URI        => mongodb://heroku_app928349384:lkfjgoierheourhgoeurhgoeuh@ds031087.mongolab.com:31087/heroku_appapp928349384
...

The important thing to note is what the left hand line says. Around the internet (like here on SO they will incorrectly name the ENV as MONGOHQ_URI. So then update mongoid.yml like this:

Additionally, it appears that different versions of mongoid only work with certain versions of mongodb. I started by digging around on google to find versions that seemed to be compatible.

Stack trace with wrong URI:
production:
  uri: <%= ENV['MONGOLAB_URI'] %>

Will yield something like

2012-02-28T12:49:46+00:00 app[web.1]: /app/.bundle/gems/ruby/1.9.1/gems/mongo-1.3.1/lib/mongo/connection.rb:518:in `connect': Failed to connect to a master node at localhost:27017 (Mongo::ConnectionFailure)
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/mongo-1.3.1/lib/mongo/connection.rb:656:in `setup'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/mongo-1.3.1/lib/mongo/connection.rb:101:in `initialize'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/mongo-1.3.1/lib/mongo/connection.rb:152:in `new'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/mongo-1.3.1/lib/mongo/connection.rb:152:in `from_uri'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/mongoid-2.0.2/lib/mongoid/config/database.rb:86:in `master'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/mongoid-2.0.2/lib/mongoid/config/database.rb:19:in `configure'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/mongoid-2.0.2/lib/mongoid/config.rb:114:in `from_hash'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/mongoid-2.0.2/lib/mongoid/config.rb:342:in `configure_databases'
2012-02-28T12:49:46+00:00 app[web.1]:  from (eval):2:in `from_hash'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/mongoid-2.0.2/lib/mongoid/railtie.rb:64:in `block in <class:Railtie>'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/initializable.rb:25:in `instance_exec'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/initializable.rb:25:in `run'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/initializable.rb:50:in `block in run_initializers'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/initializable.rb:49:in `run_initializers'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/initializable.rb:49:in `each'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/application.rb:134:in `initialize!'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/application.rb:77:in `method_missing'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/config/environment.rb:5:in `<top (required)>'
2012-02-28T12:49:46+00:00 app[web.1]:  from <internal:lib/rubygems/custom_require>:29:in `require'
2012-02-28T12:49:46+00:00 app[web.1]:  from <internal:lib/rubygems/custom_require>:29:in `require'
2012-02-28T12:49:46+00:00 app[web.1]:  from config.ru:3:in `block (3 levels) in <main>'
2012-02-28T12:49:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:23:in `eval'
2012-02-28T12:49:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:23:in `block (3 levels) in <main>'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `instance_eval'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `initialize'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:63:in `new'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:63:in `map'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `initialize'
2012-02-28T12:49:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:18:in `block (2 levels) in <main>'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `instance_eval'
2012-02-28T12:49:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:11:in `block in <main>'
2012-02-28T12:49:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:11:in `new'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `instance_eval'
2012-02-28T12:49:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `initialize'
2012-02-28T12:49:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:1:in `new'
2012-02-28T12:49:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:1:in `<main>'
2012-02-28T12:49:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/rack/adapter/loader.rb:36:in `eval'
2012-02-28T12:49:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/rack/adapter/loader.rb:36:in `load'
2012-02-28T12:49:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/controllers/controller.rb:175:in `load_rackup_config'
2012-02-28T12:49:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/controllers/controller.rb:65:in `start'
2012-02-28T12:49:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/runner.rb:177:in `run_command'
2012-02-28T12:49:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/runner.

2012-02-28T12:49:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/bin/thin:6:in `<top (required)>'
2012-02-28T12:49:46+00:00 app[web.1]:  from /usr/ruby1.9.2/bin/thin:19:in `load'
2012-02-28T12:49:46+00:00 app[web.1]:  from /usr/ruby1.9.2/bin/thin:19:in `<main>'
2012-02-28T12:49:47+00:00 heroku[web.1]: Process exited with status 1
2012-02-28T12:49:47+00:00 heroku[web.1]: State changed from starting to crashed

Stack trace with wrong version of mongo/mongoid/bson :

Starting process with command `thin -p 4644 -e production -R /home/heroku_rack/heroku.ru start`
2012-02-27T22:50:46+00:00 app[web.1]: /app/app/models/expression.rb:2:in `<class:Expression>': uninitialized constant Expression::Mongoid (NameError)
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/app/models/expression.rb:1:in `<top (required)>'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/engine.rb:138:in `block (2 levels) in eager_load!'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/engine.rb:137:in `each'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/engine.rb:137:in `block in eager_load!'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/engine.rb:135:in `eager_load!'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/engine.rb:135:in `each'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/application.rb:108:in `eager_load!'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/application/finisher.rb:41:in `block in <module:Finisher>'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/initializable.rb:25:in `instance_exec'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/initializable.rb:25:in `run'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/initializable.rb:50:in `block in run_initializers'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/initializable.rb:49:in `each'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/initializable.rb:49:in `run_initializers'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/application.rb:134:in `initialize!'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.0.8/lib/rails/application.rb:77:in `method_missing'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/config/environment.rb:5:in `<top (required)>'
2012-02-27T22:50:46+00:00 app[web.1]:  from <internal:lib/rubygems/custom_require>:29:in `require'
2012-02-27T22:50:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:23:in `eval'
2012-02-27T22:50:46+00:00 app[web.1]:  from <internal:lib/rubygems/custom_require>:29:in `require'
2012-02-27T22:50:46+00:00 app[web.1]:  from config.ru:3:in `block (3 levels) in <main>'
2012-02-27T22:50:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:23:in `block (3 levels) in <main>'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `instance_eval'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `initialize'
2012-02-27T22:50:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:18:in `block (2 levels) in <main>'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `initialize'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:63:in `new'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:63:in `map'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `instance_eval'
2012-02-27T22:50:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:11:in `new'
2012-02-27T22:50:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:11:in `block in <main>'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `instance_eval'
2012-02-27T22:50:46+00:00 app[web.1]:  from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.2.5/lib/rack/builder.rb:46:in `initialize'
2012-02-27T22:50:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:1:in `new'
2012-02-27T22:50:46+00:00 app[web.1]:  from /home/heroku_rack/heroku.ru:1:in `<main>'
2012-02-27T22:50:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/rack/adapter/loader.rb:36:in `eval'
2012-02-27T22:50:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/controllers/controller.rb:175:in `load_rackup_config'
2012-02-27T22:50:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/rack/adapter/loader.rb:36:in `load'
2012-02-27T22:50:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/controllers/controller.rb:65:in `start'
2012-02-27T22:50:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/runner.rb:177:in `run_command'
2012-02-27T22:50:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/bin/thin:6:in `<top (required)>'
2012-02-27T22:50:46+00:00 app[web.1]:  from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/runner.rb:143:in `run!'
2012-02-27T22:50:46+00:00 app[web.1]:  from /usr/ruby1.9.2/bin/thin:19:in `load'
2012-02-27T22:50:46+00:00 app[web.1]:  from /usr/ruby1.9.2/bin/thin:19:in `<main>'
2012-02-27T22:50:47+00:00 heroku[web.1]: Process exited with status 1
2012-02-27T22:50:47+00:00 heroku[web.1]: State changed from starting to crashed
2012-02-27T22:50:48+00:00 heroku[router]: Error H10 (App crashed) -> POST newsfilter.heroku.com/_heroku/console dyno= queue= wait= service= status=503 bytes=

I apologize in advance for the poor formatting on this post...

Comments

Gosha Arinich said…
I have an app with the most recent mongoid, which uses MongoLab, and runs on heroku just okay. Haven't experienced what you said.
Mike Mainguy said…
Interesting, which heroku stack are you using?
Mike Mainguy said…
And could you post the relevant parts of your Gemfile.lock?

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