Encapsulate compile and runtime configuration (#577)

config/runtime.exs

@@ -1,41 +1,2 @@
 import Config
-require Logger
+Livebook.config_runtime()
-
-config :livebook, LivebookWeb.Endpoint,
-  secret_key_base:
-    Livebook.Config.secret!("LIVEBOOK_SECRET_KEY_BASE") ||
-      Base.encode64(:crypto.strong_rand_bytes(48))
-
-if password = Livebook.Config.password!("LIVEBOOK_PASSWORD") do
-  config :livebook, authentication_mode: :password, password: password
-else
-  config :livebook, token: Livebook.Utils.random_id()
-end
-
-if port = Livebook.Config.port!("LIVEBOOK_PORT") do
-  config :livebook, LivebookWeb.Endpoint, http: [port: port]
-end
-
-if ip = Livebook.Config.ip!("LIVEBOOK_IP") do
-  config :livebook, LivebookWeb.Endpoint, http: [ip: ip]
-end
-
-config :livebook,
-       :cookie,
-       Livebook.Config.cookie!("LIVEBOOK_COOKIE") ||
-         Livebook.Config.cookie!("RELEASE_COOKIE") ||
-         Livebook.Utils.random_cookie()
-
-config :livebook,
-       :default_runtime,
-       Livebook.Config.default_runtime!("LIVEBOOK_DEFAULT_RUNTIME") ||
-         {Livebook.Runtime.ElixirStandalone, []}
-
-root_path =
-  Livebook.Config.root_path!("LIVEBOOK_ROOT_PATH")
-  |> Livebook.FileSystem.Utils.ensure_dir_path()
-
-local_file_system = Livebook.FileSystem.Local.new(default_path: root_path)
-configured_file_systems = Livebook.Config.file_systems!("LIVEBOOK_FILE_SYSTEM_")
-
-config :livebook, :file_systems, [local_file_system | configured_file_systems]

lib/livebook.ex

@@ -5,6 +5,58 @@ defmodule Livebook do
   This module includes the public API.
   """
 
+  @doc """
+  Executes Livebook's config/runtime.exs.
+
+  If you use Livebook as a dependency, you can add the following
+  to your `config/runtime.exs` to trigger Livebook's config/runtime.exs
+  configuration:
+
+      Livebook.config_runtime()
+
+  """
+  def config_runtime do
+    import Config
+
+    config :livebook, LivebookWeb.Endpoint,
+      secret_key_base:
+        Livebook.Config.secret!("LIVEBOOK_SECRET_KEY_BASE") ||
+          Base.encode64(:crypto.strong_rand_bytes(48))
+
+    if port = Livebook.Config.port!("LIVEBOOK_PORT") do
+      config :livebook, LivebookWeb.Endpoint, http: [port: port]
+    end
+
+    if ip = Livebook.Config.ip!("LIVEBOOK_IP") do
+      config :livebook, LivebookWeb.Endpoint, http: [ip: ip]
+    end
+
+    if password = Livebook.Config.password!("LIVEBOOK_PASSWORD") do
+      config :livebook, authentication_mode: :password, password: password
+    else
+      config :livebook, token: Livebook.Utils.random_id()
+    end
+
+    if runtime = Livebook.Config.default_runtime!("LIVEBOOK_DEFAULT_RUNTIME") do
+      config :livebook, :default_runtime, runtime
+    end
+
+    config :livebook,
+           :cookie,
+           Livebook.Config.cookie!("LIVEBOOK_COOKIE") ||
+             Livebook.Config.cookie!("RELEASE_COOKIE") ||
+             Livebook.Utils.random_cookie()
+
+    root_path =
+      Livebook.Config.root_path!("LIVEBOOK_ROOT_PATH")
+      |> Livebook.FileSystem.Utils.ensure_dir_path()
+
+    local_file_system = Livebook.FileSystem.Local.new(default_path: root_path)
+    configured_file_systems = Livebook.Config.file_systems!("LIVEBOOK_FILE_SYSTEM_")
+
+    config :livebook, :file_systems, [local_file_system | configured_file_systems]
+  end
+
   @doc """
   Parses the given Live Markdown document and converts it to Elixir
   source code.

mix.exs

@@ -24,7 +24,8 @@ defmodule Livebook.MixProject do
   def application do
     [
       mod: {Livebook.Application, []},
-      extra_applications: [:logger, :runtime_tools, :os_mon, :inets, :ssl, :xmerl]
+      extra_applications: [:logger, :runtime_tools, :os_mon, :inets, :ssl, :xmerl],
+      env: Application.get_all_env(:livebook)
     ]
   end