Trying to connect to a mongodb instance on ec2 with mongoid as orm in rails
development:
 host: localhost
 database: mongotest_development

test:
 host: localhost
 database: mongotest_test

set these environment variables on your prod server
production:
 host: <%= ENV['MONGOID_HOST'] %>
 port: <%= ENV['MONGOID_PORT'] %>
 username: <%= ENV['MONGOID_USERNAME'] %>
 password: <%= ENV['MONGOID_PASSWORD'] %>
 database: <%= ENV['MONGOID_DATABASE'] %>
 # slaves:
 #   - host: slave1.local
 #     port: 27018
 #   - host: slave2.local
 #     port: 27019

development:
 host: <public dns of the mongodb instance>
 port: 27017
 # username:
 # password:
 database: <I ssh into the instance and created a database>

Failed to connect to a master node at <public dns of the mongodb instance>:27017 (Mongo::ConnectionFailure)
from /Users/Kinglee/.rvm/gems/ruby-1.9.2-p180@rails3tutorial/gems/mongo-1.6.2/lib/mongo/connection.rb:589:in `setup'
from /Users/Kinglee/.rvm/gems/ruby-1.9.2-p180@rails3tutorial/gems/mongo-1.6.2/lib/mongo/connection.rb:114:in `initialize'
from /Users/Kinglee/.rvm/gems/ruby-1.9.2-p180@rails3tutorial/gems/mongo-1.6.2/lib/mongo/connection.rb:165:in `new'
from /Users/Kinglee/.rvm/gems/ruby-1.9.2-p180@rails3tutorial/gems/mongo-1.6.2/lib/mongo/connection.rb:165:in `from_uri'
from /Users/Kinglee/.rvm/gems/ruby-1.9.2-p180@rails3tutorial/gems/mongoid-2.4.10/lib/mongoid/config/database.rb:86:in `master'
from /Users/Kinglee/.rvm/gems/ruby-1.9.2-p180@rails3tutorial/gems/mongoid-2.4.10/lib/mongoid/config/database.rb:19:in `configure'
from /Users/Kinglee/.rvm/gems/ruby-1.9.2-p180@rails3tutorial/gems/mongoid-2.4.10/lib/mongoid/config.rb:290:in `configure_databases'
....

bind_ip = 127.0.0.1

bind_ip = 0.0.0.0