Support dynamic event stores

[slashdotdash]

Allow a dynamically named and configured EventStore to be started by Commanded. The optional name is included in the event store meta data and passed to all event store functions.

Example usage

Define an application which uses the init/1 callback function to set the event store name and schema from config:

defmodule MyApp.Application do
  use Commanded.Application,
    otp_app: :my_app,
    event_store: [
      adapter: Commanded.EventStore.Adapters.EventStore,
      event_store: MyApp.EventStore
    ]

  def init(config) do
    name = Keyword.fetch!(config, :name)
    {schema, config} = Keyword.pop(config, :schema)

    config = put_in(config, [:event_store, :name], Module.concat([name, EventStore])
    config = put_in(config, [:event_store, :schema], schema)

    {:ok, config}
  end
end

Start an application per tenant with each using a separate event store and schema:

for tenant <- [:tenant1, :tenant2, :tenant3] do
  {:ok, _pid} = MyApp.Application.start_link(name: tenant, schema: Atom.to_string(tenant))
end