Support specifying erl flags for standalone runtime node (#2843)

lib/livebook/runtime/standalone.ex

@@ -1,5 +1,5 @@
 defmodule Livebook.Runtime.Standalone do
-  defstruct [:node, :server_pid]
+  defstruct [:erl_flags, :node, :server_pid]
 
   # A runtime backed by a standalone Elixir node managed by Livebook.
   #
@@ -31,16 +31,23 @@ defmodule Livebook.Runtime.Standalone do
   alias Livebook.Utils
 
   @type t :: %__MODULE__{
+          erl_flags: String.t() | nil,
           node: node() | nil,
           server_pid: pid() | nil
         }
 
   @doc """
   Returns a new runtime instance.
+
+  ## Options
+
+    * `:erl_flags` - erl flags to specify when starting the node
+
   """
-  @spec new() :: t()
-  def new() do
-    %__MODULE__{}
+  @spec new(keyword()) :: t()
+  def new(opts \\ []) do
+    opts = Keyword.validate!(opts, [:erl_flags])
+    %__MODULE__{erl_flags: opts[:erl_flags]}
   end
 
   def __connect__(runtime) do
@@ -66,7 +73,7 @@ defmodule Livebook.Runtime.Standalone do
       ]
 
       with {:ok, elixir_path} <- find_elixir_executable(),
-           port = start_elixir_node(elixir_path, child_node),
+           port = start_elixir_node(elixir_path, child_node, runtime.erl_flags),
            {:ok, server_pid} <- parent_init_sequence(child_node, port, init_opts) do
         runtime = %{runtime | node: child_node, server_pid: server_pid}
         send(caller, {:runtime_connect_done, self(), {:ok, runtime}})
@@ -84,7 +91,7 @@ defmodule Livebook.Runtime.Standalone do
     end
   end
 
-  defp start_elixir_node(elixir_path, node_name) do
+  defp start_elixir_node(elixir_path, node_name, erl_flags) do
     # Here we create a port to start the system process in a non-blocking way.
     Port.open({:spawn_executable, elixir_path}, [
       :binary,
@@ -93,7 +100,7 @@ defmodule Livebook.Runtime.Standalone do
       # to the terminal
       :nouse_stdio,
       :hide,
-      args: elixir_flags(node_name)
+      args: elixir_flags(node_name, erl_flags)
     ])
   end
 
@@ -167,7 +174,7 @@ defmodule Livebook.Runtime.Standalone do
     |> Base.encode64()
   end
 
-  defp elixir_flags(node_name) do
+  defp elixir_flags(node_name, erl_flags) do
     parent_name = node()
     parent_port = Livebook.EPMD.dist_port()
 
@@ -190,7 +197,8 @@ defmodule Livebook.Runtime.Standalone do
       #     startup
       #
       "+sbwt none +sbwtdcpu none +sbwtdio none +sssdio 128 -elixir ansi_enabled true -noinput " <>
-        "-epmd_module Elixir.Livebook.Runtime.EPMD",
+        "-epmd_module Elixir.Livebook.Runtime.EPMD " <>
+        (erl_flags || ""),
       # Add the location of Livebook.Runtime.EPMD
       "-pa",
       epmd_module_path!(),
@@ -247,8 +255,8 @@ defimpl Livebook.Runtime, for: Livebook.Runtime.Standalone do
     :ok = RuntimeServer.stop(runtime.server_pid)
   end
 
-  def duplicate(_runtime) do
-    Livebook.Runtime.Standalone.new()
+  def duplicate(runtime) do
+    Livebook.Runtime.Standalone.new(erl_flags: runtime.erl_flags)
   end
 
   def evaluate_code(runtime, language, code, locator, parent_locators, opts \\ []) do

lib/livebook_web/live/apps_dashboard_live.ex

@@ -60,7 +60,7 @@ defmodule LivebookWeb.AppsDashboardLive do
     <div class="flex flex-col space-y-4">
       <div :for={app <- Enum.sort_by(@apps, & &1.slug)} data-app-slug={app.slug}>
         <a
-          phx-click={JS.toggle(to: "[data-app-slug=#{app.slug}] .toggle")}
+          phx-click={JS.toggle(to: "[data-app-slug=#{app.slug}] [data-toggle]")}
           class="flex items-center justify-between mb-2 hover:cursor-pointer"
         >
           <span class="text-gray-800 font-medium text-xl break-all">
@@ -68,11 +68,11 @@ defmodule LivebookWeb.AppsDashboardLive do
           </span>
           <div class="flex items-center gap-2">
             <.app_group_tag app_spec={app.app_spec} />
-            <.remix_icon icon="arrow-drop-down-line" class="text-3xl text-gray-400 toggle" />
-            <.remix_icon icon="arrow-drop-right-line" class="text-3xl text-gray-400 hidden toggle" />
+            <.remix_icon icon="arrow-down-s-line" class="text-xl text-gray-700" data-toggle />
+            <.remix_icon icon="arrow-right-s-line" class="text-xl text-gray-700 hidden" data-toggle />
           </div>
         </a>
-        <div class="toggle">
+        <div data-toggle>
           <div :if={app.warnings != []} class="my-3 flex flex-col gap-3">
             <.message_box :for={warning <- app.warnings} kind={:warning} message={warning} />
           </div>

lib/livebook_web/live/session_live/attached_runtime_component.ex

@@ -78,7 +78,7 @@ defmodule LivebookWeb.SessionLive.AttachedRuntimeComponent do
         autocomplete="off"
         spellcheck="false"
       >
-        <div class="flex flex-col space-y-4 mb-5">
+        <div class="flex flex-col space-y-4 mb-6">
           <.text_field field={f[:name]} label="Name" placeholder={test_node()} />
           <.text_field field={f[:cookie]} label="Cookie" placeholder="mycookie" />
         </div>

lib/livebook_web/live/session_live/standalone_runtime_component.ex

@@ -1,6 +1,8 @@
 defmodule LivebookWeb.SessionLive.StandaloneRuntimeComponent do
   use LivebookWeb, :live_component
 
+  import Ecto.Changeset
+
   alias Livebook.{Session, Runtime}
 
   @impl true
@@ -12,30 +14,115 @@ defmodule LivebookWeb.SessionLive.StandaloneRuntimeComponent do
     {:ok, socket}
   end
 
+  @impl true
+  def update(assigns, socket) do
+    changeset =
+      case socket.assigns[:changeset] do
+        nil ->
+          changeset(assigns.runtime)
+
+        changeset when socket.assigns.runtime == assigns.runtime ->
+          changeset
+
+        changeset ->
+          changeset(assigns.runtime, changeset.params)
+      end
+
+    socket =
+      socket
+      |> assign(assigns)
+      |> assign(:changeset, changeset)
+
+    {:ok, socket}
+  end
+
+  defp changeset(runtime, attrs \\ %{}) do
+    data =
+      case runtime do
+        %Runtime.Standalone{erl_flags: erl_flags} ->
+          %{erl_flags: erl_flags}
+
+        _ ->
+          %{erl_flags: nil}
+      end
+
+    types = %{erl_flags: :string}
+
+    cast({data, types}, attrs, [:erl_flags])
+  end
+
   @impl true
   def render(assigns) do
     ~H"""
-    <div class="flex-col space-y-5">
+    <div id={@id} class="flex-col space-y-5">
       <p class="text-gray-700">
         Start a new local Elixir node to evaluate code. Whenever you reconnect this runtime,
         a fresh node is started.
       </p>
-      <.button phx-click="init" phx-target={@myself} disabled={@runtime_status == :connecting}>
-        <%= label(@runtime, @runtime_status) %>
-      </.button>
+      <.form
+        :let={f}
+        for={@changeset}
+        as={:data}
+        phx-submit="init"
+        phx-change="validate"
+        phx-target={@myself}
+        autocomplete="off"
+        spellcheck="false"
+      >
+        <div id={"#{@id}-advanced"} class="mb-6">
+          <div
+            class="flex items-center gap-0.5 text-gray-700 font-medium cursor-pointer"
+            phx-click={JS.toggle(to: "##{@id}-advanced [data-toggle]")}
+          >
+            <span>Advanced configuration</span>
+            <.remix_icon icon="arrow-down-s-line" class="text-xl hidden" data-toggle />
+            <.remix_icon icon="arrow-right-s-line" class="text-xl" data-toggle />
+          </div>
+          <div class="mt-2 flex flex-col space-y-4 hidden" data-toggle>
+            <.text_field field={f[:erl_flags]} label="Erl flags" />
+          </div>
+        </div>
+        <.button type="submit" disabled={@runtime_status == :connecting or not @changeset.valid?}>
+          <%= label(@changeset, @runtime_status) %>
+        </.button>
+      </.form>
     </div>
     """
   end
 
-  defp label(%Runtime.Standalone{}, :connecting), do: "Connecting..."
-  defp label(%Runtime.Standalone{}, :connected), do: "Reconnect"
-  defp label(_runtime, _runtime_status), do: "Connect"
+  defp label(changeset, runtime_status) do
+    reconnecting? = changeset.valid? and changeset.data == apply_changes(changeset)
+
+    case {reconnecting?, runtime_status} do
+      {true, :connected} -> "Reconnect"
+      {true, :connecting} -> "Connecting..."
+      _ -> "Connect"
+    end
+  end
 
   @impl true
-  def handle_event("init", _params, socket) do
-    runtime = Runtime.Standalone.new()
-    Session.set_runtime(socket.assigns.session.pid, runtime)
-    Session.connect_runtime(socket.assigns.session.pid)
-    {:noreply, socket}
+  def handle_event("validate", %{"data" => data}, socket) do
+    changeset =
+      socket.assigns.runtime
+      |> changeset(data)
+      |> Map.replace!(:action, :validate)
+
+    {:noreply, assign(socket, changeset: changeset)}
+  end
+
+  def handle_event("init", %{"data" => data}, socket) do
+    socket.assigns.runtime
+    |> changeset(data)
+    |> apply_action(:insert)
+    |> case do
+      {:ok, data} ->
+        runtime = Runtime.Standalone.new(erl_flags: data.erl_flags)
+        Session.set_runtime(socket.assigns.session.pid, runtime)
+        Session.connect_runtime(socket.assigns.session.pid)
+        {:noreply, socket}
+
+      {:error, changeset} ->
+        {:noreply, assign(socket, changeset: changeset)}
+    end
   end
 end

test/livebook_web/live/session_live_test.exs

@@ -907,8 +907,8 @@ defmodule LivebookWeb.SessionLiveTest do
       |> render_click()
 
       view
-      |> element("#runtime-settings-modal button", "Connect")
-      |> render_click()
+      |> element("#runtime-settings-modal form")
+      |> render_submit(%{data: %{}})
 
       assert_receive {:operation, {:set_runtime, _pid, %Runtime.Standalone{}}}
       assert_receive {:operation, {:runtime_connected, _pid, %Runtime.Standalone{} = runtime}}