action-requests-demo.jamey.stream/lib/action_requests_demo/release.ex

defmodule ActionRequestsDemo.Release do
  @moduledoc """
  Helpers for running tasks in a release environment.

  This module is intended for commands invoked via:

      bin/action_requests_demo eval "ActionRequestsDemo.Release.seed()"
  """

  @app :action_requests_demo

  @doc """
  Run the database seeds script inside a release.

  This is designed to be run against a *running* release (e.g. via
  `bin/action_requests_demo eval ...` inside your Docker container),
  so it does **not** try to start the application or endpoint again.
  It only ensures Faker is running, then evaluates the standard
  `priv/repo/seeds.exs` file, which uses `ActionRequestsDemo.Repo`.
  """
  def seed do
    ensure_app_started(ActionRequestsDemo.Repo)
    ensure_app_started(:faker)

    seeds_path = Application.app_dir(@app, "priv/repo/seeds.exs")
    Code.require_file(seeds_path)
  end

  defp ensure_app_started(app_or_repo) do
    case Application.ensure_all_started(app_or_repo) do
      {:ok, _} ->
        :ok

      {:error, {:already_started, _pid}} ->
        :ok

      {:error, {:not_started, _}} ->
        start_repo(app_or_repo)

      {:error, reason} ->
        raise "Could not start #{inspect(app_or_repo)}: #{inspect(reason)}"
    end
  rescue
    UndefinedFunctionError ->
      start_repo(app_or_repo)
  end

  defp start_repo(repo) when is_atom(repo) do
    case repo.start_link() do
      {:ok, _pid} ->
        :ok

      {:error, {:already_started, _pid}} ->
        :ok

      other ->
        raise "Could not start #{inspect(repo)}: #{inspect(other)}"
    end
  end

  defp start_repo(app) do
    case Application.ensure_all_started(app) do
      {:ok, _} -> :ok
      {:error, {:already_started, _}} -> :ok
      other -> raise "Could not start #{inspect(app)}: #{inspect(other)}"
    end
  end
end