Support start_permanent

Author: José Valim

lib/mix/lib/mix/project.ex

@@ -400,7 +400,8 @@ defmodule Mix.Project do
      erlc_include_path: "include",
      erlc_options: [:debug_info],
      lockfile: "mix.lock",
-     preferred_cli_env: []]
+     preferred_cli_env: [],
+     start_permanent: false]
   end
 
   defp get_project_config(nil),  do: []

lib/mix/lib/mix/tasks/app.start.ex

@@ -1,15 +1,23 @@
 defmodule Mix.Tasks.App.Start do
   use Mix.Task
 
+  @shortdoc "Start all registered apps"
   @recursive true
 
   @moduledoc """
-  Starts all registered apps. If no apps key exists,
-  it starts the current application.
+  Starts all registered apps.
+
+  The application is started by default as temporary. In case
+  `:start_permanent` is set to true in your prject configuration
+  or the `--permanent` flag is given, it is started as permanent,
+  which guarantee the node will shutdown in case the application
+  crashes permanently.
 
   ## Command line options
 
     * `--force` - force compilation regardless of compilation times
+    * `--temporary` - start the application as temporary
+    * `--permanent` - start the application as permanent
     * `--no-compile` - do not compile even if files require compilation
     * `--no-protocols` - do not load consolidated protocols
     * `--no-deps-check` - do not check dependencies
@@ -20,6 +28,8 @@ defmodule Mix.Tasks.App.Start do
   @spec run(OptionParser.argv) :: :ok
   def run(args) do
     Mix.Project.get!
+
+    {opts, _, _} = OptionParser.parse args, switches: [permanent: :boolean, temporary: :boolean]
     Mix.Task.run "loadpaths", args
 
     unless "--no-compile" in args do
@@ -47,14 +57,14 @@ defmodule Mix.Tasks.App.Start do
       #
       # Mix should not depend directly on Logger so check that it's loaded.
       if Code.ensure_loaded?(Logger), do: Logger.App.stop()
-      start(Mix.Project.config[:app])
+      start(Mix.Project.config, opts)
     end
   end
 
   @doc false
-  def start(app) do
-    if app do
-      case Application.ensure_all_started(app) do
+  def start(config, opts) do
+    if app = config[:app] do
+      case Application.ensure_all_started(app, type(config, opts)) do
         {:ok, _} -> :ok
         {:error, {app, reason}} ->
           Mix.raise "Could not start application #{app}: " <>
@@ -64,4 +74,14 @@ defmodule Mix.Tasks.App.Start do
       :error
     end
   end
+
+  @doc false
+  def type(config, opts) do
+    cond do
+      opts[:temporary] -> :temporary
+      opts[:permanent] -> :permanent
+      config[:start_permanent] -> :permanent
+      true -> :temporary
+    end
+  end
 end

lib/mix/test/mix/tasks/app.start_test.exs

@@ -5,7 +5,7 @@ defmodule Mix.Tasks.App.StartTest do
 
   defmodule AppStartSample do
     def project do
-      [app: :app_start_sample, version: "0.1.0"]
+      [app: :app_start_sample, version: "0.1.0", start_permanent: true]
     end
 
     def application do
@@ -89,7 +89,14 @@ defmodule Mix.Tasks.App.StartTest do
   end
 
   test "start does nothing if app is nil" do
-    assert Mix.Tasks.App.Start.start(nil) == :error
+    assert Mix.Tasks.App.Start.start([app: nil], []) == :error
+  end
+
+  test "allows type to be configured" do
+    assert Mix.Tasks.App.Start.type([], [permanent: true]) == :permanent
+    assert Mix.Tasks.App.Start.type([], [temporary: true]) == :temporary
+    assert Mix.Tasks.App.Start.type([start_permanent: true], []) == :permanent
+    assert Mix.Tasks.App.Start.type([], []) == :temporary
   end
 
   defmodule ReturnSample do
@@ -115,9 +122,12 @@ defmodule Mix.Tasks.App.StartTest do
       Process.put(:application_definition, mod: {ReturnApp, {:error, :bye}})
       Mix.Tasks.Compile.run []
 
-      assert_raise Mix.Error, "Could not start application return_sample: Mix.Tasks.App.StartTest.ReturnApp.start(:normal, {:error, :bye}) returned an error: :bye",
-      fn ->
-        Mix.Tasks.App.Start.start(:return_sample)
+      message = "Could not start application return_sample: " <>
+                "Mix.Tasks.App.StartTest.ReturnApp.start(:normal, {:error, :bye}) " <>
+                "returned an error: :bye"
+
+      assert_raise Mix.Error, message, fn ->
+        Mix.Tasks.App.Start.start([app: :return_sample], [])
       end
     end
   end
@@ -130,10 +140,14 @@ defmodule Mix.Tasks.App.StartTest do
           {:badarg, [{ReturnApp, :start, 2, []}] }}})
       Mix.Tasks.Compile.run []
 
-      assert_raise Mix.Error, "Could not start application return_sample: Mix.Tasks.App.StartTest.ReturnApp.start(:normal, {:error, {:badarg, [{Mix.Tasks.App.StartTest.ReturnApp, :start, 2, []}]}}) returned an error: an exception was raised:\n" <>
-        "    ** (ArgumentError) argument error\n" <>
-        "        Mix.Tasks.App.StartTest.ReturnApp.start/2", fn ->
-      Mix.Tasks.App.Start.start(:return_sample)
+      message = "Could not start application return_sample: " <>
+                "Mix.Tasks.App.StartTest.ReturnApp.start(:normal, {:error, {:badarg, [{Mix.Tasks.App.StartTest.ReturnApp, :start, 2, []}]}}) " <>
+                "returned an error: an exception was raised:\n" <>
+                "    ** (ArgumentError) argument error\n" <>
+                "        Mix.Tasks.App.StartTest.ReturnApp.start/2"
+
+      assert_raise Mix.Error, message, fn ->
+        Mix.Tasks.App.Start.start([app: :return_sample], [])
       end
     end
   end
@@ -145,9 +159,12 @@ defmodule Mix.Tasks.App.StartTest do
       Process.put(:application_definition, mod: {ReturnApp, :bad})
       Mix.Tasks.Compile.run []
 
-      assert_raise Mix.Error, "Could not start application return_sample: Mix.Tasks.App.StartTest.ReturnApp.start(:normal, :bad) returned a bad value: :bad",
-      fn ->
-        Mix.Tasks.App.Start.start(:return_sample)
+      message = "Could not start application return_sample: " <>
+                "Mix.Tasks.App.StartTest.ReturnApp.start(:normal, :bad) " <>
+                "returned a bad value: :bad"
+
+      assert_raise Mix.Error, message, fn ->
+        Mix.Tasks.App.Start.start([app: :return_sample], [])
       end
     end
   end
@@ -175,10 +192,12 @@ defmodule Mix.Tasks.App.StartTest do
       Process.put(:application_definition, mod: {ExitApp, :bye})
       Mix.Tasks.Compile.run []
 
-      assert_raise Mix.Error, "Could not start application exit_sample: exited in: Mix.Tasks.App.StartTest.ExitApp.start(:normal, :bye)\n" <>
-      "    ** (EXIT) :bye",
-         fn ->
-        Mix.Tasks.App.Start.start(:exit_sample)
+      message = "Could not start application exit_sample: exited in: " <>
+                "Mix.Tasks.App.StartTest.ExitApp.start(:normal, :bye)\n" <>
+                "    ** (EXIT) :bye"
+
+      assert_raise Mix.Error, message, fn ->
+        Mix.Tasks.App.Start.start([app: :exit_sample], [])
       end
     end
   end
@@ -190,10 +209,12 @@ defmodule Mix.Tasks.App.StartTest do
       Process.put(:application_definition, mod: {ExitApp, :normal})
       Mix.Tasks.Compile.run []
 
-      assert_raise Mix.Error, "Could not start application exit_sample: exited in: Mix.Tasks.App.StartTest.ExitApp.start(:normal, :normal)\n" <>
-      "    ** (EXIT) normal",
-         fn ->
-        Mix.Tasks.App.Start.start(:exit_sample)
+      message = "Could not start application exit_sample: exited in: " <>
+                "Mix.Tasks.App.StartTest.ExitApp.start(:normal, :normal)\n" <>
+                "    ** (EXIT) normal"
+
+      assert_raise Mix.Error, message, fn ->
+        Mix.Tasks.App.Start.start([app: :exit_sample], [])
       end
     end
   end