Spear EventStoreDB adapter for Commanded

Commanded EvenstoreDB adapter based on spear. The code is based on commanded-extreme-adapter.

Hex package

Changelog

Getting started

The package can be installed from hex as follows.

  1. Add commanded_spear_adapter to your list of dependencies in mix.exs:

    def deps do

      [{:commanded_spear_adapter, "~> 0.1"}]

    end

  2. Define and configure your Commanded application:

    defmodule MyApp.Application do

      use Commanded.Application, otp_app: :my_app

    end

  3. Configure the Commanded application to use the Commanded.EventStore.Adapters.Spear adapter and set the connection settings for the Event Store you are using:

    # config/config.exs

    config :my_app, MyApp.Application,

      event_store: [

        adapter: Commanded.EventStore.Adapters.Spear,

        serializer: Commanded.Serialization.JsonSerializer,

        stream_prefix: "myapp",

        spear: [

          connection_string: "esdb://localhost:2113"

        ]

      ]

    Refer to the Spear library documentation for details on the available connection settings.

    Note: Stream prefix must not contain a dash character ("-").

Use a serializer other than JSON

To serialize and deserialize events in formats other than JSON, you must specify the content-type of the event body.

# config/config.exs

config :my_app, MyApp.Application,

  event_store: [

    adapter: Commanded.EventStore.Adapters.Spear,

    serializer: MyApp.MessagePackSerializer,

    content_type: "application/x-msgpack"

    ...

  ]

The content_type settings defaults to application/json.

Running the Event Store

You must run the Event Store with all projections enabled and standard projections started.

Use the --run-projections=all --start-standard-projections=true flags when running the Event Store executable.

Credits