Rails Engine + Mongoid: No configuration could be found for a session named 'default' - rails-engines

Question

I've created a Rails Mountable App and added 'mongoid' and 'rspec' gem's. If I try to run my specs now I get the following error:
Mongoid::Errors::NoSessionConfig:
Problem:
No configuration could be found for a session named 'default'.
Summary:
When attempting to create the new session, Mongoid could not find a session configuration for the name: 'default'. This is necessary in order to know the host, port, and options needed to connect.
Resolution:
Double check your mongoid.yml to make sure under the sessions key that a configuration exists for 'default'. If you have set the configuration programatically, ensure that 'default' exists in the configuration hash.
When I add the Mongoid.load!(Rails.root.join("config", "mongoid.yml")) line to spec_helper.rb everything works normal.
Why is that and how can I get the functionality like in a normal Rails app where I don't need to call the load function?
mongoid.yml
development:
sessions:
default:
database: dummy_development
hosts:
- localhost:27017
options:
options:
test:
sessions:
default:
database: dummy_test
hosts:
- localhost:27017
options:
consistency: :strong
max_retries: 1
retry_interval: 0
Versions:
gem 'rails', '~> 3.2.12'
gem 'mongoid', '~> 3.1'
gem 'rspec-rails', '~> 2.13'

Answer 1

you probably missed require 'rails/mongoid' in your spec_helper.rb file.
Had someone having the same issue in here https://github.com/mongoid/mongoid/issues/2894#issuecomment-14903927
Try adding that require, that should fix it.

Answer 2

This worked for me on my machine
1: Add this to your config/application.rb
Mongoid.load!("path to your mongoid.yml")
2: And change your mongoid.yml from (Only for mongoid version < 5):
This
development:
clients:
default:
database: database_for_development
hosts:
- localhost:27017
test:
clients:
default:
database: database_for_test
hosts:
- localhost:27017
production:
clients:
default:
database: database_for_production
hosts:
- localhost:27017
To:
development:
sessions:
default:
database: database_for_development
hosts:
- localhost:27017
test:
sessions:
default:
database: database_for_test
hosts:
- localhost:27017
production:
sessions:
default:
database: database_for_production
hosts:
- localhost:27017

Answer 3

This is probably because of two simultaneous conditions: ( there is no production section in mongoid.yml ) AND ( Heroku treats Rails applications as production by default ).
Fixing either one shall suffice.
1. There is no production section in mongoid.yml
Add production section to mongoid.yml, as explained at Heroku , e.g.
production:
sessions:
default:
uri: <%= ENV['MONGOHQ_URL'] %>
options:
skip_version_check: true
safe: true
2. Heroku treats rails applications as production by default
Set Heroku environment to development, or a add a new environment which would be specific to Heroku, as explained at Heroku, e.g.
heroku config:set RACK_ENV=development RAILS_ENV=development --remote development

Answer 4

And restart the server after making changes to mongoid.yml

Answer 5

I've found this working - notice there is no "sessions", only "clients"
production:
clients:
default:
uri: <%= ENV['MONGODB_URI'] %>
options:
skip_version_check: true
safe: true

Answer 6

Try to regenerate a new mongoid.yml:
rails g mongoid:config
And after change mongoid.yml with your values.