OpenStax Swift Ecto integration

OpenStax Swift Ecto eases using OpenStack Swift with Ecto models.

Status

Project in the early stage of development. API may change without prior warning.

Introduction

This module simplifies using OpenStax Swift storage with Ecto Models.

It exposes several functions that allow to easily upload/download files that should be logically bound to certain record.

It automatically performs MIME type checks and ensures that uploaded files have right MIME type in the storage.

By design, only one file per record is allowed.

If either file_type or file_size, file_etag, file_name fields will be present in the model it will be automatically updated. Names of these fields can be overriden by overriding swift_file_size_field, swift_file_type_field, swift_file_etag_field and swift_file_name_field functions. Override this to functions that return nil to disable that feature.

An example model that uses OpenStax.Swift.Ecto.Model:

defmodule MyApp.MyModel do
  use Ecto.Model
  use OpenStax.Swift.Ecto.Model

  @required_fields ~w()
  @optional_fields ~w(file_size file_type file_etag file_name)

  schema "mymodel" do
    field :file_size, :integer
    field :file_type, :string
    field :file_etag, :string
    field :file_name, :string
    timestamps
  end

  def swift_endpoint_id(_record), do: :myendpoint
  def swift_container(_record),   do: :somecontainer
  def swift_object_id(record),    do: "something_" <> record.id

  def changeset(model, params \\ :empty) do
    model
    |> cast(params, @required_fields, @optional_fields)
  end
end

An example usage:

defmodule MyApp.MyLogic do
  def attach_file_to_record(record_id, path) do
    record = MyApp.Repo.get!(MyApp.MyModel, record_id)

    case OpenStax.Swift.Ecto.Model.upload(MyApp.Repo, record, {:file, path}) do
      {:ok, record} ->
        IO.puts "OK " <> OpenStax.Swift.Ecto.Model.temp_url(record)

      {:error, reason} ->
        IO.puts "ERROR " <> inspect(reason)
    end
  end
end

Authors

Marcin Lewandowski marcin@saepia.net

License

MIT