This module provides a simple way to add additional processing to phases of the release assembly and archival.

Implementing your own plugin

To create a Distillery plugin, create a new module in which you use Mix.Releases.Plugin. Then write implementations for the following callbacks:

• before_assembly/2
• after_assembly/2
• before_package/2
• after_package/2
• after_cleanup/2

The default implementation is to pass the original %Release{}. You will only need to implement the functions your plugin requires.

When you use Mix.Releases.Plugin, the following happens:

• Your module is marked with @behaviour Mix.Releases.Plugin.
• The Mix.Releases.Release struct is aliased to %Release{}.
• The functions debug/1, info/1, warn/1, notice/1, and error/1 are imported from Mix.Releases.Shell. These should be used to present output to the user.

The first four callbacks (before_assembly/2, after_assembly/2, before_package/2, and after_package/2) will each be passed the %Release{} struct and options passed to the plugin. You can return a modified struct, or nil. Any other return value will lead to runtime errors.

after_cleanup/2 is only invoked on mix release.clean. It will be passed the command line arguments. The return value is not used.

Example

defmodule MyApp.PluginDemo do
  use Mix.Releases.Plugin

  def before_assembly(%Release{} = release, _opts) do
    info "This is executed just prior to assembling the release"
    release # or nil
  end

  def after_assembly(%Release{} = release, _opts) do
    info "This is executed just after assembling, and just prior to packaging the release"
    release # or nil
  end

  def before_package(%Release{} = release, _opts) do
    info "This is executed just before packaging the release"
    release # or nil
  end

  def after_package(%Release{} = release, _opts) do
    info "This is executed just after packaging the release"
    release # or nil
  end

  def after_cleanup(_args, _opts) do
    info "This is executed just after running cleanup"
    :ok # It doesn't matter what we return here
  end
end