christhekeele

defmodule MyApp.Foo do
  @on_definition MyApp.SpecToCallback
  
  @spec bar(String.t()) :: String.t()
  def bar(foobar) do
    impl().bar(foobar)
  end
  
  defp impl, do: Application.get_env(:my_app, :my_app_foo_impl, __MODULE__.DefaultImpl)
end

christhekeele

Last update: 2020-03-17

Flask-SQLAlchemy has some nice built-ins (e.g. accessing query directly on classes). To continue leveraging these nicities while still inside of a Celery worker, we need to make sure we setup/teardown in a similar fashion to Flask-SQLAlchemy does on Flask.

Setup

Flask-SQLAlchemy uses create_scoped_session at startup which avoids any setup on a per-request basis.

https://github.com/mitsuhiko/flask-sqlalchemy/blob/2.0/flask_sqlalchemy/__init__.py#L668

This means Celery can piggyback off of this initialization.

christhekeele

# config.rb

after_configuration do
  if defined?(RailsAssets)
    RailsAssets.load_paths.each do |path|
      sprockets.append_path path  unless sprockets.paths.include? path
      Dir[File.join(path, '*')].select do |contents|
        File.file? contents
      end.map do |file|
        Pathname.new File.basename file