Gemfile:

gem "mongoid_rails_migrations"

Create migration

$ rails generate mongoid:migration <your_migration_name_here>

Run migrations:

$ rails db:migrate
$ rails db:migrate:down VERSION=
$ rails db:migrate:up VERSION=
$ rails db:rollback
$ rails db:rollback_to VERSION=
$ rails db:migrate:redo
$ rails db:migrate:reset
$ rails db:migrate:status
$ rails db:reseed (handled by mongoid)
$ rails db:version

If you want to use output migration use the hook after_migrate

Mongoid::Migration.after_migrate = ->(output, name, direction, crash) {
  upload_to_s3(name, output, direction) if crash == false
}

To override the default migrations path (db/migrate), add the following line to your application.rb file:

Mongoid::Migrator.migrations_path = ['foo/bar/db/migrate', 'path/to/db/migrate']

Default behavior is to store migrations in the default client database but for projects that require horizontal scalabilty, this gem supports migrations sharding.

To generate a migration that can be run on shards, suffix the migration generator command with --shards like:

$ rails generate mongoid:migration <your_migration_name_here> --shards

The migration will be created and stored in db/migrate/shards folder.

With the following configuration:

production:
  clients:
    default:
      database: my_production_db
      hosts:
        - 4.2.4.2:27017
    shard1:
      database: my_shard1_production_db
      hosts:
        - 5.3.5.3:27017
    shard2:
      database: my_shard2_production_db
      hosts:
        - 6.4.6.4:27017

In order to manage a sharded migration, run tasks with the MONGOID_CLIENT_NAME environment variable:

$ rails db:migrate MONGOID_CLIENT_NAME=shard2

The shards migrations will be executed and entries will be added in the my_shard2_production_db database.

All the rake tasks support the MONGOID_CLIENT_NAME environment variable.

To make shards migrations the default migration type, add the following line in your config:

# config/application.rb

Mongoid.configure.shards_migration_as_default = true

Global migrations can still be created with the --no-shards option.

• 1.5.x targets Mongoid >= 5.0 and Rails >= 4.2
• 1.4.x targets Mongoid >= 4.0 and Rails >= 4.2
• 1.0.0 targers Mongoid >= 3.0 and Rails >= 3.2
• 0.0.14 targets Mongoid >= 2.0 and Rails >= 3.0 (but < 3.2)

Compare master with 1.6.0

12/09/2024

• Remove unnecessary purge, setup, reset, etc. rake tasks because they are already defined by Mongoid (#60)
• Minor tests improvements
• Rejects Mongoid 9.0 for the moment because it broke client override isolation: https://jira.mongodb.org/browse/MONGOID-5815
• Setup Github Actions to replace Travis CI (because It could not be fixed without the maintainer, see #55)
• Remove some legacy comments and unreachable code

26/03/2021

• Add support of multi databases
• Shards migrations can now be stored in a shards subfolder inside the migration folder
• All Rake tasks now support a custom client with the MONGOID_CLIENT_NAME environment variable

08/01/2021

• The hook after_migrate can be use when migration crash (#56)

17/12/2020

• Rake Tasks updated to use migrations_path instead of hardcoded path (#52)
• Added after_migrate hook(#54)

17/01/2019

• Fix on db:migrate:status task to behave like the ActiveRecord version (#47)

23/10/2018

• Added a rollback_to task to rollback to a particular version (#17)
• Added a db:migrate:status task to list pending migrations (#46)

18/08/2015

• Added support for Rails5
• First version in Changelog

$ bundle exec rake

• rails
• mongoid
• contributions from the community (git log)

Much of this gem simply modifies existing code from both projects. With that out of the way, on to the license.

Copyright © 2013: Alan Da Costa

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

The software is provided 'as is', without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and noninfringement. In no event shall the authors or copyright holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the software or the use or other dealings in the software.