I want to disable Rails from trying to obtain a connection to my Postgres database because my application no longer should rely on this database.
I'm currently in a transition from using Postgres to using a NoSQL database such as Mongo. I have most of the code migrated but I'm currently running a shadow write to Postgres for backwards compatibility reasons.
Is it sufficient to remove the ActiveRecord middlewares and shadow write code so that if Postgres were to fail or the connection pool stalled the Rails application would experience no timeout or downtime?
To remove ActiveRecord from your application, do the following:
In config/application.rb, change this:
require 'rails/all'
To this:
require "active_model/railtie"
require "active_job/railtie"
require "action_controller/railtie"
require "action_mailer/railtie"
require "action_view/railtie"
require "action_cable/engine"
require "sprockets/railtie"
require "rails/test_unit/railtie"
In environments/development.rb, remove this line, and any others that reference config.active_record that you may have added:
config.active_record.migration_error = :page_load
In environments/production.rb remove this line and any others that reference config.active_record that you may have added:
config.active_record.dump_schema_after_migration = false
If you have a file at config/initializers/new_framework_defaults.rb, remove the following line from it:
Rails.application.config.active_record.belongs_to_required_by_default = true
Finally, remove any references to ActiveRecord, such as in any models, migrations, or schema.rb, if still present. It's probably best to nuke your db folder entirely.
Note: If you're no longer using any of ActiveModel you can also remove it from the requires in application.rb.
To remove support and functionality for connecting to your Postgres database, remove the file config/database.yml and remove the gem 'pg' declaration from your Gemfile (then run bundle install).
Related
My project was created using PostgresSQL but we really intend to use MongoDB, what should I change in order for that to happen?
A lot of scaffolding already took place, so we are trying to savage any of the work already done...
Remove database adapter gems from your Gemfile (mysql2, sqlite3, etc.)
Change your config/application.rb
Remove require 'rails/all' line and require frameworks you want to use, for example:
require "action_controller/railtie"
require "action_view/railtie"
require "action_mailer/railtie"
require "active_job/railtie"
require "action_cable/engine"
require "sprockets/railtie"
require "rails/test_unit/railtie"
NOTE: You should be using the require snippet from the rails/all.rb file that is current with your version of Rails without the active_record railtie. Here is a link to rails/all.rb on the Rails master branch.
Delete your config/database.yml file, db/schema.rb and migrations (if any)
Delete migration check in test/test_helper.rb
Delete any ActiveRecord configuration from your config/environments files
Better late than never! This should come in handy to somebody, someday!!!!
The following python-based migration framework does the job.
https://github.com/datawrangl3r/pg2mongo
Coming to the performance, the migration of each JSON object is dynamic and there shouldn't be any memory lock issues when you use the above framework.
The same situation I also I have to face . I am adding some additional points to above answer .
1) Create a file in initializers and put this code
Mongoid.load!(Rails.root.join("config/mongoid.yml"))
2) You have to remove from every model which are inheriting from ApplicationRecord and delete the application_record file.
3) If you have installed devise so you have to change
**From **
require 'devise/orm/active_record'
to
require 'devise/orm/mongoid'
4) If you are using carrierwave so in gem file you have to replace
From
gem 'carrierwave', github: 'carrierwaveuploader/carrierwave'
To
gem 'carrierwave-mongoid', :require => 'carrierwave/mongoid'
I want to disable ActiveRecord in Rails 4. I did the following in config/application.rb
require File.expand_path('../boot', __FILE__)
# require 'rails/all' -- commented
require "action_controller/railtie"
require "action_mailer/railtie"
#require "active_resource/railtie" no need
#require "rails/test_unit/railtie" no need
#require "sprockets/railtie" no need
# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(:default, Rails.env)
module MyApp
class Application < Rails::Application
config.app_middleware.delete "ActiveRecord::ConnectionAdapters::ConnectionManagement"
end
end
By I have an error of
/home/alex/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/railtie/configuration.rb:95:in
method_missing: undefined method active_record for #<Rails::Application::Configuration:0x00000002005c38> (NoMethodError)
If you are creating a new application, you can use -O to skip ActiveRecord:
rails new my_app -O
For existing applications:
1. Remove database adapter gems from your Gemfile (mysql2, sqlite3, etc.)
2. Change your config/application.rb
Remove require 'rails/all line and require frameworks (among those available in your rails version, the list varies, do not just copy) you want to use, for example:
require "action_controller/railtie"
require "action_mailer/railtie"
require "sprockets/railtie"
require "rails/test_unit/railtie"
Remove config.active_record.raise_in_transactional_callbacks = true from config/application.rb
3. Delete your config/database.yml file, db/schema.rb and migrations (if any)
4. Delete migration check in test/test_helper.rb
5. Delete any ActiveRecord configuration from your config/environments files (this is what is causing your error)
This is all you need to do for an empty Rails app. If you run into problems caused by your existing code, stack trace should give you sufficient information on what you need to change. You might for example have some ActiveRecord configuration in your initializers.
Hi this is what the default rails new new_app -O gives
require "rails"
# Pick the frameworks you want:
require "active_model/railtie"
require "active_job/railtie"
# require "active_record/railtie"
require "action_controller/railtie"
require "action_mailer/railtie"
require "action_view/railtie"
require "sprockets/railtie"
require "rails/test_unit/railtie"
inside your config/application.rb
Additionally, it comes without database.yml and NO db/migrate/* and schema.rb
Since this is still the first hit when searching Google for disabling active record for Rails 5, I'll add this here:
For Rails 5
Do all the steps in #mechanicalfish answer, but also remove the line
Rails.application.config.active_record.belongs_to_required_by_default = true
from
config/initializers/new_framework_defaults.rb
For those using the rails-api gem you may encounter a similar error when using the --skip-active-record flag when doing rails-api new my_api. The current fix (until a new corrected version of the gem is released) is to edit your rails-api gem to have this commit. Use bundle open and replace the old Gemfile with the new corrected one. Rerun and you should be all set.
For disable ActiveRecord in Rails 4.2 you may create config/initializers/middleware.rb
Rails.application.middleware.tap do |middleware|
middleware.delete ActiveRecord::Migration::CheckPending
middleware.delete ActiveRecord::ConnectionAdapters::ConnectionManagement
middleware.delete ActiveRecord::QueryCache
end
See the terminal rake middleware
For Rails 5:
If you are generating a new app
Use --skip-active-record option to generate an application without a database:
rails new myApp --skip-active-record
Notice the extra hyphen '-' as opposed to previous versions of Rails.
For Rails Plugins (or gems) with a spec/dummy app
When your rails app lives in spec/dummy and you start your server from the plugin-root directory. You might still getting following error:
Cannot load `Rails.application.database_configuration`: Could not load database configuration. No such file - ["config/database.yml"]
To avoid this, remove require rails/all inside the file bin/rails and require frameworks you want to use, for example:
# Pick the frameworks you want:
require "active_model/railtie"
require "active_job/railtie"
# require "active_record/railtie"
require "action_cable/engine"
require "action_controller/railtie"
require "action_mailer/railtie"
require "action_view/railtie"
require "sprockets/railtie"
require "rails/test_unit/railtie"
For Ruby On Rails version 5.1.x
require "rails"
# Pick the frameworks you want:
require "active_model/railtie"
require "active_job/railtie"
# require "active_record/railtie"
require "action_controller/railtie"
require "action_mailer/railtie"
require "action_view/railtie"
require "action_cable/engine"
require "sprockets/railtie"
require "rails/test_unit/railtie"
I want to disable ActiveRecord in Rails 4. I did the following in config/application.rb
require File.expand_path('../boot', __FILE__)
# require 'rails/all' -- commented
require "action_controller/railtie"
require "action_mailer/railtie"
#require "active_resource/railtie" no need
#require "rails/test_unit/railtie" no need
#require "sprockets/railtie" no need
# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(:default, Rails.env)
module MyApp
class Application < Rails::Application
config.app_middleware.delete "ActiveRecord::ConnectionAdapters::ConnectionManagement"
end
end
By I have an error of
/home/alex/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/railtie/configuration.rb:95:in
method_missing: undefined method active_record for #<Rails::Application::Configuration:0x00000002005c38> (NoMethodError)
If you are creating a new application, you can use -O to skip ActiveRecord:
rails new my_app -O
For existing applications:
1. Remove database adapter gems from your Gemfile (mysql2, sqlite3, etc.)
2. Change your config/application.rb
Remove require 'rails/all line and require frameworks (among those available in your rails version, the list varies, do not just copy) you want to use, for example:
require "action_controller/railtie"
require "action_mailer/railtie"
require "sprockets/railtie"
require "rails/test_unit/railtie"
Remove config.active_record.raise_in_transactional_callbacks = true from config/application.rb
3. Delete your config/database.yml file, db/schema.rb and migrations (if any)
4. Delete migration check in test/test_helper.rb
5. Delete any ActiveRecord configuration from your config/environments files (this is what is causing your error)
This is all you need to do for an empty Rails app. If you run into problems caused by your existing code, stack trace should give you sufficient information on what you need to change. You might for example have some ActiveRecord configuration in your initializers.
Hi this is what the default rails new new_app -O gives
require "rails"
# Pick the frameworks you want:
require "active_model/railtie"
require "active_job/railtie"
# require "active_record/railtie"
require "action_controller/railtie"
require "action_mailer/railtie"
require "action_view/railtie"
require "sprockets/railtie"
require "rails/test_unit/railtie"
inside your config/application.rb
Additionally, it comes without database.yml and NO db/migrate/* and schema.rb
Since this is still the first hit when searching Google for disabling active record for Rails 5, I'll add this here:
For Rails 5
Do all the steps in #mechanicalfish answer, but also remove the line
Rails.application.config.active_record.belongs_to_required_by_default = true
from
config/initializers/new_framework_defaults.rb
For those using the rails-api gem you may encounter a similar error when using the --skip-active-record flag when doing rails-api new my_api. The current fix (until a new corrected version of the gem is released) is to edit your rails-api gem to have this commit. Use bundle open and replace the old Gemfile with the new corrected one. Rerun and you should be all set.
For disable ActiveRecord in Rails 4.2 you may create config/initializers/middleware.rb
Rails.application.middleware.tap do |middleware|
middleware.delete ActiveRecord::Migration::CheckPending
middleware.delete ActiveRecord::ConnectionAdapters::ConnectionManagement
middleware.delete ActiveRecord::QueryCache
end
See the terminal rake middleware
For Rails 5:
If you are generating a new app
Use --skip-active-record option to generate an application without a database:
rails new myApp --skip-active-record
Notice the extra hyphen '-' as opposed to previous versions of Rails.
For Rails Plugins (or gems) with a spec/dummy app
When your rails app lives in spec/dummy and you start your server from the plugin-root directory. You might still getting following error:
Cannot load `Rails.application.database_configuration`: Could not load database configuration. No such file - ["config/database.yml"]
To avoid this, remove require rails/all inside the file bin/rails and require frameworks you want to use, for example:
# Pick the frameworks you want:
require "active_model/railtie"
require "active_job/railtie"
# require "active_record/railtie"
require "action_cable/engine"
require "action_controller/railtie"
require "action_mailer/railtie"
require "action_view/railtie"
require "sprockets/railtie"
require "rails/test_unit/railtie"
For Ruby On Rails version 5.1.x
require "rails"
# Pick the frameworks you want:
require "active_model/railtie"
require "active_job/railtie"
# require "active_record/railtie"
require "action_controller/railtie"
require "action_mailer/railtie"
require "action_view/railtie"
require "action_cable/engine"
require "sprockets/railtie"
require "rails/test_unit/railtie"
I created a rails app with the -O option (i.e. without ActiveRecord). But now I want to add active record to it. How can I accomplish that?
Inside of config/application.rb you should see where the ActiveRecord railtie is commented out (see below).
# Pick the frameworks you want:
# require "active_record/railtie"
require "action_controller/railtie"
require "action_mailer/railtie"
require "active_resource/railtie"
require "sprockets/railtie"
require "rails/test_unit/railtie"
Uncomment it.
Also make sure to add a database.yml file and the a database adapter gem (e.g. sqlite3) to your Gemfile.
Now that Rails 3 beta is out, I thought I'd have a look at rewriting an app I have just started work on in Rails 3 beta, both to get a feel for it and get a bit of a head-start. The app uses MongoDB and MongoMapper for all of its models and therefore has no need for ActiveRecord. In the previous version, I am unloading activerecord in the following way:
config.frameworks -= [ :active_record ] # inside environment.rb
In the latest version this does not work - it just throws an error:
/Library/Ruby/Gems/1.8/gems/railties-3.0.0.beta/lib/rails/configuration.rb:126:in
`frameworks': config.frameworks in no longer supported. See the generated
config/boot.rb for steps on how to limit the frameworks that will be loaded
(RuntimeError)
from *snip*
Of course, I have looked at the boot.rb as it suggested, but as far as I can see, there is no clue here as to how I might go about unloading AR. The reason I need to do this is because not only is it silly to be loading something I don't want, but it is complaining about its inability to make a DB connection even when I try to run a generator for a controller. This is because I've wiped database.yml and replaced it with connection details for MongoDB in order to use this gist for using database.yml for MongoDB connection details. Not sure why it needs to be able to initiate a DB connection at all just to generate a controller anyway....
Is anyone aware of the correct Rails 3 way of doing this?
I'm going by this from reading the source, so let me know if it actually worked. :)
The rails command that generates the application template now has an option -O, which tells it to skip ActiveRecord.
If you don't feel like rerunning rails, you should check the following in your existing app:
Check that your config/application.rb doesn't have require 'rails/all' or require "active_record/railtie". Instead, for a standard Rails setup without ActiveRecord, it should have only the following requires:
require File.expand_path('../boot', __FILE__)
require "action_controller/railtie"
require "action_mailer/railtie"
require "active_resource/railtie"
require "rails/test_unit/railtie"
require "sprockets/railtie"
# Auto-require default libraries and those for the current Rails environment.
Bundler.require :default, Rails.env
If, in config/application.rb, you are using the config.generators section, make sure it doesn't have the line g.orm :active_record. You can set this explicitly to nil, if you want, but this should be the default when g.orm is completely omitted.
Optional, but in your Gemfile, remove the gem line that loads the module for your database. This could be the line gem "mysql" for example.
Rails 4
I was looking for how to disable it in rails 4 and only found this answer which no longer works in rails 4. So this is how you can do it in rails 4 (tested in RC1).
In a new project
rails new YourProject --skip-active-record
In an existing project
In your Gemfile, remove the database driver gem, e.g. gem 'sqlite3' or gem 'pg'.
In config/application.rb, replace require 'rails/all' with
require "action_controller/railtie"
require "action_mailer/railtie"
require "sprockets/railtie"
require "rails/test_unit/railtie"
In config/environments/development.rb, remove or comment out config.active_record.migration_error = :page_load
Potentially you have to remove active_record helpers from the spec_helper (via VenoM in the comments)
Potentially you have to remove the ConnectionManagement middleware (seems to be the case with unicorn): config.app_middleware.delete "ActiveRecord::ConnectionAdapters::ConnectionManagement" (via https://stackoverflow.com/a/18087332/764342)
I hope this helps others looking for how to disable ActiveRecord in Rails 4.
For a new rails app, you can have it exclude active record by specifying the --skip-active-record parameter. Eg:
rails new appname --skip-active-record
If you generated a new project using Rails 3.2, you will also need to comment out:
config.active_record.mass_assignment_sanitizer = :strict
and
config.active_record.auto_explain_threshold_in_seconds = 0.5
in your development.rb file.
All of the above are true. The one more thing which I had to do in rails 3.1 is to comment out
config.active_record.identity_map = true
in config/application.rb.
If you're running rspec, you also need to remove (in spec_helper):
# Remove this line if you're not using ActiveRecord or ActiveRecord fixtures
config.fixture_path = "#{::Rails.root}/spec/fixtures"
and remove
# If you're not using ActiveRecord, or you'd prefer not to run each of your
# examples within a transaction, remove the following line or assign false
# instead of true.
config.use_transactional_fixtures = true
Also comment out
# config/application.rb
config.active_record.whitelist_attributes = true
(noted on rails 3.2.13)