Rails app doesn't run on AWS Elastic Beanstalk, passenger error

I have been trying to get started running Rails on AWS' Elastic Beanstalk, While running my rails application, getting following error.

Instead of seeing my rails app (which, by the way, runs fine locally), I get the dreaded "We're sorry, but something went wrong" page:

Logs

/var/app/support/logs/passenger.log

App 3676 stdout: 
App 3676 stdout: 
[ 2015-03-11 11:06:44.6211 3139/7f7bba716700 Pool2/Implementation.cpp:287 ]: Could not spawn process for application /var/app/current: An error occured while starting up the preloader.
  Error ID: 444a4118
  Error details saved to: /tmp/passenger-error-jgrbjG.html
  Message from application: database configuration does not specify adapter (ActiveRecord::AdapterNotSpecified)
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/connection_adapters/abstract/connection_specification.rb:47:in `resolve_hash_connection'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/connection_adapters/abstract/connection_specification.rb:41:in `resolve_string_connection'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/connection_adapters/abstract/connection_specification.rb:25:in `spec'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/connection_adapters/abstract/connection_specification.rb:130:in `establish_connection'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/railtie.rb:88:in `block (2 levels) in <class:Railtie>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activesupport-3.2.17/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activesupport-3.2.17/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activesupport-3.2.17/lib/active_support/lazy_load_hooks.rb:26:in `block in on_load'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activesupport-3.2.17/lib/active_support/lazy_load_hooks.rb:25:in `each'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activesupport-3.2.17/lib/active_support/lazy_load_hooks.rb:25:in `on_load'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/railtie.rb:80:in `block in <class:Railtie>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/initializable.rb:30:in `instance_exec'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/initializable.rb:30:in `run'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/initializable.rb:55:in `block in run_initializers'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/initializable.rb:54:in `each'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/initializable.rb:54:in `run_initializers'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/application.rb:136:in `initialize!'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/railtie/configurable.rb:30:in `method_missing'
  /var/app/current/config/environment.rb:5:in `<top (required)>'
  config.ru:3:in `require'
  config.ru:3:in `block in <main>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize'
  config.ru:1:in `new'
  config.ru:1:in `<main>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:112:in `eval'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:112:in `preload_app'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:158:in `<module:App>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:29:in `<module:PhusionPassenger>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:28:in `<main>'


[ 2015-03-11 11:06:44.6322 3139/7f7bb3fff700 agents/HelperAgent/RequestHandler.h:2306 ]: [Client 20] Cannot checkout session because a spawning error occurred. The identifier of the error is 444a4118. Please see earlier logs for details about the error.
[ 2015-03-11 11:06:44.6324 3139/7f7bb3fff700 agents/HelperAgent/RequestHandler.h:2306 ]: [Client 26] Cannot checkout session because a spawning error occurred. The identifier of the error is 444a4118. Please see earlier logs for details about the error.
App 3749 stdout: 
App 3749 stdout: 
[ 2015-03-11 11:13:58.5266 3139/7f7bba716700 Pool2/Implementation.cpp:287 ]: Could not spawn process for application /var/app/current: An error occured while starting up the preloader.
  Error ID: 04ef27b3
  Error details saved to: /tmp/passenger-error-vFuwfd.html
  Message from application: database configuration does not specify adapter (ActiveRecord::AdapterNotSpecified)
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/connection_adapters/abstract/connection_specification.rb:47:in `resolve_hash_connection'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/connection_adapters/abstract/connection_specification.rb:41:in `resolve_string_connection'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/connection_adapters/abstract/connection_specification.rb:25:in `spec'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/connection_adapters/abstract/connection_specification.rb:130:in `establish_connection'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/railtie.rb:88:in `block (2 levels) in <class:Railtie>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activesupport-3.2.17/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activesupport-3.2.17/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activesupport-3.2.17/lib/active_support/lazy_load_hooks.rb:26:in `block in on_load'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activesupport-3.2.17/lib/active_support/lazy_load_hooks.rb:25:in `each'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activesupport-3.2.17/lib/active_support/lazy_load_hooks.rb:25:in `on_load'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-3.2.17/lib/active_record/railtie.rb:80:in `block in <class:Railtie>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/initializable.rb:30:in `instance_exec'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/initializable.rb:30:in `run'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/initializable.rb:55:in `block in run_initializers'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/initializable.rb:54:in `each'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/initializable.rb:54:in `run_initializers'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/application.rb:136:in `initialize!'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/railties-3.2.17/lib/rails/railtie/configurable.rb:30:in `method_missing'
  /var/app/current/config/environment.rb:5:in `<top (required)>'
  config.ru:3:in `require'
  config.ru:3:in `block in <main>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize'
  config.ru:1:in `new'
  config.ru:1:in `<main>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:112:in `eval'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:112:in `preload_app'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:158:in `<module:App>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:29:in `<module:PhusionPassenger>'
  /opt/rubies/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/passenger-4.0.53/helper-scripts/rack-preloader.rb:28:in `<main>'


[ 2015-03-11 11:13:58.5380 3139/7f7bb3fff700 agents/HelperAgent/RequestHandler.h:2306 ]: [Client 20] Cannot checkout session because a spawning error occurred. The identifier of the error is 04ef27b3. Please see earlier logs for details about the error.
[ 2015-03-11 11:13:58.5382 3139/7f7bb3fff700 agents/HelperAgent/RequestHandler.h:2306 ]: [Client 26] Cannot checkout session because a spawning error occurred. The identifier of the error is 04ef27b3. Please see earlier logs for details about the error.

Please help.