I am creating application in Ruby on Rails which is having many engines(for modularity).
I want different databases for each engine. How to configure this?
Database - MYSQL
Add a comment
|
2 Answers
There is a good explanation by the link http://www.blrice.net/blog/2016/04/09/one-rails-app-with-many-databases/
1 Comment
New Alexandria
I know this answer may be old-business to you, but it would be best if you resummarize major points about the article you cite. That article can go away, and this answer would then be meaningless.
General approach is to take a look at the framework sources and decide can it be reused.
Let's take a look at activerecord/lib/active_record/railties/databases.rake (v5.0.7) first. For example on how db:create implemented.
We will see ActiveRecord::Tasks::DatabaseTasks.create_current.
Let's open ActiveRecord::Tasks::DatabaseTasks and take a look at
# The possible config values are:
#
# * +env+: current environment (like Rails.env).
# * +database_configuration+: configuration of your databases (as in +config/database.yml+).
# * +db_dir+: your +db+ directory.
# * +fixtures_path+: a path to fixtures directory.
# * +migrations_paths+: a list of paths to directories with migrations.
# * +seed_loader+: an object which will load seeds, it needs to respond to the +load_seed+ method.
# * +root+: a path to the root of the application.
#
# Example usage of DatabaseTasks outside Rails could look as such:
#
# include ActiveRecord::Tasks
# DatabaseTasks.database_configuration = YAML.load_file('my_database_config.yml')
# DatabaseTasks.db_dir = 'db'
# # other settings...
This way we are getting to following solution:
namespace :your_engine do
namespace :db do
task :load_config do
ActiveRecord::Tasks::DatabaseTasks.database_configuration = YAML.load_file("config/database_your_engine.yml")
ActiveRecord::Tasks::DatabaseTasks.db_dir = "db_your_engine"
ActiveRecord::Tasks::DatabaseTasks.migrations_paths = [ "components/your_engine/db/migrate" ]
ActiveRecord::Base.configurations = ActiveRecord::Tasks::DatabaseTasks.database_configuration
ActiveRecord::Migrator.migrations_paths = ActiveRecord::Tasks::DatabaseTasks.migrations_paths
# You can observe following values to see how settings applied.
# puts ActiveRecord::Base.configurations
# puts ActiveRecord::Migrator.migrations_paths
# puts ActiveRecord::Tasks::DatabaseTasks.database_configuration
# puts ActiveRecord::Tasks::DatabaseTasks.migrations_paths
end
desc "Create Your DB"
task create: :load_config do
ActiveRecord::Tasks::DatabaseTasks.create_current
end
end
end
The same approach for drop/migrate and other needed tasks.
It is good general rule - know you stack at least one level lower than your work with. Sometimes reading underlying sources much more helpful than direct answer.
I will update this answer while going forward with my solution...
