diff --git a/Gemfile b/Gemfile
index 93b2ca4..43ed208 100644
--- a/Gemfile
+++ b/Gemfile
@@ -17,7 +17,7 @@ gem 'strong_parameters'
 gem 'SystemTimer', :platform => :ruby_18
 gem 'actionmailer_inline_css'
 gem 'kaminari', '>= 0.14.1'
-gem 'rack-ssl-enforcer'
+gem 'rack-ssl-enforcer', :require => false
 # fabrication 1.3.0 is last supporting ruby 1.8. Update when stop supporting this version too
 gem 'fabrication', "~> 1.3.0"   # Used for both tests and demo data
 gem 'rails_autolink'
diff --git a/config/initializers/_load_config.rb b/config/initializers/_load_config.rb
index 6086b11..64f8396 100644
--- a/config/initializers/_load_config.rb
+++ b/config/initializers/_load_config.rb
@@ -4,15 +4,17 @@ default_config_file = Rails.root.join("config", "config.example.yml")
 # Allow a Rails Engine to override config by defining it earlier
 unless defined?(Errbit::Config)
   Errbit::Config = OpenStruct.new
+  use_env = ENV['HEROKU'] || ENV['USE_ENV']
 
   # If Errbit is running on Heroku, config can be set from environment variables.
-  if ENV['HEROKU']
+  if use_env
     Errbit::Config.host = ENV['ERRBIT_HOST']
     Errbit::Config.email_from = ENV['ERRBIT_EMAIL_FROM']
-    Errbit::Config.email_at_notices = ENV['ERRBIT_EMAIL_AT_NOTICES']
-    Errbit::Config.confirm_resolve_err = ENV['ERRBIT_CONFIRM_RESOLVE_ERR']
-    Errbit::Config.user_has_username = ENV['ERRBIT_USER_HAS_USERNAME']
-    Errbit::Config.allow_comments_with_issue_tracker = ENV['ERRBIT_ALLOW_COMMENTS_WITH_ISSUE_TRACKER']
+    #  Not really easy to use like an env because need an array and ENV return a string :(
+    # Errbit::Config.email_at_notices = ENV['ERRBIT_EMAIL_AT_NOTICES']
+    Errbit::Config.confirm_resolve_err = ENV['ERRBIT_CONFIRM_RESOLVE_ERR'].to_i == 0
+    Errbit::Config.user_has_username = ENV['ERRBIT_USER_HAS_USERNAME'].to_i == 1
+    Errbit::Config.allow_comments_with_issue_tracker = ENV['ERRBIT_ALLOW_COMMENTS_WITH_ISSUE_TRACKER'].to_i == 0
     Errbit::Config.enforce_ssl = ENV['ERRBIT_ENFORCE_SSL']
 
     Errbit::Config.use_gravatar = ENV['ERRBIT_USE_GRAVATAR']
@@ -29,7 +31,7 @@ unless defined?(Errbit::Config)
       :authentication => :plain,
       :user_name      => ENV['SMTP_USERNAME']   || ENV['SENDGRID_USERNAME'],
       :password       => ENV['SMTP_PASSWORD']   || ENV['SENDGRID_PASSWORD'],
-      :domain         => ENV['SENDGRID_DOMAIN'] || ENV['ERRBIT_EMAIL_FROM'].split('@').last
+      :domain         => ENV['SMTP_DOMAIN'] || ENV['SENDGRID_DOMAIN'] || ENV['ERRBIT_EMAIL_FROM'].split('@').last
     }
   end
 
@@ -44,7 +46,7 @@ unless defined?(Errbit::Config)
       Errbit::Config.send("#{k}=", v)
     end
   # Show message if we are not running tests, not running on Heroku, and config.yml doesn't exist.
-  elsif not ENV['HEROKU']
+  elsif not use_env
     puts "Please copy 'config/config.example.yml' to 'config/config.yml' and configure your settings. Using default settings."
   end
 
@@ -76,4 +78,4 @@ end
 
 if Rails.env.production?
   Rails.application.config.consider_all_requests_local = Errbit::Config.display_internal_errors
-end
\ No newline at end of file
+end
diff --git a/config/initializers/mongo.rb b/config/initializers/mongo.rb
index 30b1377..0a91121 100644
--- a/config/initializers/mongo.rb
+++ b/config/initializers/mongo.rb
@@ -1,12 +1,33 @@
-if mongo = ENV['MONGOLAB_URI'] || ENV['MONGOHQ_URL']
-  settings = URI.parse(mongo)
-  database_name = settings.path.gsub(/^\//, '')
+# Some code extract from Mongoid gem
+config_file = Rails.root.join("config", "mongoid.yml")
+if config_file.file? &&
+  YAML.load(ERB.new(File.read(config_file)).result)[Rails.env].values.flatten.any?
+  ::Mongoid.load!(config_file)
+else
+  # No mongoid.yml file. Use ENV variable to define your MongoDB
+  # configuration
+  if mongo = ENV['MONGOLAB_URI'] || ENV['MONGOHQ_URL']
+    settings = URI.parse(mongo)
+    database_name = settings.path.gsub(/^\//, '')
+  else
+    settings = OpenStruct.new({
+      :host => ENV['MONGOID_HOST'],
+      :port => ENV['MONGOID_PORT'],
+      :user => ENV['MONGOID_USERNAME'],
+      :password => ENV['MONGOID_PASSWORD']
+    })
+    database_name = ENV['MONGOID_DATABASE']
+  end
 
   Mongoid.configure do |config|
-    config.master = Mongo::Connection.new(settings.host, settings.port).db(database_name)
+    config.master = Mongo::Connection.new(
+      settings.host,
+      settings.port
+    ).db(database_name)
     config.master.authenticate(settings.user, settings.password) if settings.user
-    config.allow_dynamic_fields = false
-    config.use_activesupport_time_zone = true
   end
 end
 
+Mongoid.allow_dynamic_fields = false
+Mongoid.use_activesupport_time_zone = true
+Mongoid.identity_map_enabled = true
diff --git a/config/initializers/ssl_enforcer.rb b/config/initializers/ssl_enforcer.rb
index 106f347..03c8ed8 100755
--- a/config/initializers/ssl_enforcer.rb
+++ b/config/initializers/ssl_enforcer.rb
@@ -1,5 +1,6 @@
 # Enforce SSL connections, if configured
 if Errbit::Config.enforce_ssl
+  require 'rack/ssl-enforcer'
   ActionMailer::Base.default_url_options.merge!(:protocol => 'https://')
   Errbit::Application.configure do
     config.middleware.use Rack::SslEnforcer, :except => /^\/deploys/
diff --git a/docs/ENV-VARIABLES.md b/docs/ENV-VARIABLES.md
new file mode 100644
index 0000000..0463e0a
--- /dev/null
+++ b/docs/ENV-VARIABLES.md
@@ -0,0 +1,59 @@
+# Which env variable you can use ?
+
+Errbit can be almost configured by some ENVIRONMENT variables. If you
+use this variable, you don't need copy all of you configuration file
+
+To activate this env variable you need activate it by a Variable env.
+You can do that with HEROKU or USE_ENV variable
+
+If you activate it you can use all of this env variable :
+
+## Errbit base configuration
+
+* ERRBIT_HOST : the host of your errbit instance (not define by default)
+* ERRBIT_EMAIL_FROM : the email sending all of your notification (not
+  define by default )
+* ERRBIT_CONFIRM_RESOLVE_ERR : define if you need confirm when you mark
+  a problem resolve. ( true by default, fill it and you not need
+confirm )
+* ERRBIT_USER_HAS_USERNAME : allow identify your user by username
+  instead of email. ( false by default, set to '1' to activate it)
+* ERRBIT_ALLOW_COMMENTS_WITH_ISSUE_TRACKER : define if you activate the
+  comment or not. By default comment are
+* ERRBIT_ENFORCE_SSL : allow force the ssl on all the application. By
+  default is false
+* ERRBIT_USE_GRAVATAR : allow use gravatar to see user gravatar in user
+  comment and page
+
+## Authentification configuration
+
+Environement variable allow define how you can auth on your errbit
+
+### Github authentification
+
+You can allow the GITHUB auth
+
+* GITHUB_AUTHENTIFICATION : define if you allow the github auth. By
+  default false
+* GITHUB_CLIENT_ID : you github app client id to use in your github auth
+* GITHUB_SECRET : your github app secret to use in your github auth
+* GITHUB_ACCESS_SCOPE : The scope to ask to access on github account
+
+## Email sending configuration
+
+* SMTP_SERVER
+* SMTP_PORT
+* SMTP_USERNAME
+* SMTP_PASSWORD
+* SMTP_DOMAIN
+
+## MongoDB
+
+* MONGOLAB_URI
+* MONGOHQ_URL
+* MONGOID_HOST
+* MONGOID_PORT
+* MONGOID_USERNAME
+* MONGOID_PASSWORD
+* MONGOID_DATABASE
+
--
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