Show information when a new Livebook version is available (#1121)

* Show information when a new Livebook version is available

* Wording

* Use more precise version comparison

* Update lib/livebook/application.ex

Co-authored-by: José Valim <jose.valim@dashbit.co>

* Up

* Update notificaion styles

* Update lib/livebook_web/live/home_live.ex

Co-authored-by: José Valim <jose.valim@dashbit.co>

* Update lib/livebook_web/live/home_live.ex

Co-authored-by: José Valim <jose.valim@dashbit.co>

* Apply review comments

* Use async_nolink

Co-authored-by: José Valim <jose.valim@dashbit.co>

README.md

@@ -196,6 +196,9 @@ The following environment variables configure Livebook:
     Enabled by default unless `LIVEBOOK_PASSWORD` is set. Set it to "false" to
     disable it.
 
+  * LIVEBOOK_UPDATE_INSTRUCTIONS_URL - sets the URL to direct the user to for
+    updating Livebook when a new version becomes available.
+
 <!-- Environment variables -->
 
 If running Livebook as a Docker image or an Elixir release, [the environment

lib/livebook.ex

@@ -155,6 +155,11 @@ defmodule Livebook do
              :app_service_url,
              Livebook.Config.app_service_url!("LIVEBOOK_APP_SERVICE_URL")
     end
+
+    if update_instructions_url =
+         Livebook.Config.update_instructions_url!("LIVEBOOK_UPDATE_INSTRUCTIONS_URL") do
+      config :livebook, :update_instructions_url, update_instructions_url
+    end
   end
 
   @doc """

lib/livebook/application.ex

@@ -18,16 +18,18 @@ defmodule Livebook.Application do
         LivebookWeb.Telemetry,
         # Start the PubSub system
         {Phoenix.PubSub, name: Livebook.PubSub},
+        # Start a supervisor for Livebook tasks
+        {Task.Supervisor, name: Livebook.TaskSupervisor},
         # Start the storage module
         Livebook.Storage.current(),
-        # Periodid measurement of system resources
+        # Start the periodic version check
+        Livebook.UpdateCheck,
+        # Periodic measurement of system resources
         Livebook.SystemResources,
         # Start the tracker server on this node
         {Livebook.Tracker, pubsub_server: Livebook.PubSub},
         # Start the supervisor dynamically managing sessions
         {DynamicSupervisor, name: Livebook.SessionSupervisor, strategy: :one_for_one},
-        # Start a supervisor for Livebook tasks
-        {Task.Supervisor, name: Livebook.TaskSupervisor},
         # Start the server responsible for associating files with sessions
         Livebook.Session.FileGuard,
         # Start the Node Pool for managing node names

lib/livebook/config.ex

@@ -122,6 +122,14 @@ defmodule Livebook.Config do
     Application.fetch_env!(:livebook, :app_service_url)
   end
 
+  @doc """
+  Returns the update check URL.
+  """
+  @spec update_instructions_url() :: String.t() | nil
+  def update_instructions_url() do
+    Application.get_env(:livebook, :update_instructions_url)
+  end
+
   ## Parsing
 
   @doc """
@@ -254,6 +262,13 @@ defmodule Livebook.Config do
     System.get_env(env)
   end
 
+  @doc """
+  Parses update instructions url from env.
+  """
+  def update_instructions_url!(env) do
+    System.get_env(env)
+  end
+
   @doc """
   Parses and validates default runtime from env.
   """

lib/livebook/settings.ex

@@ -13,7 +13,7 @@ defmodule Livebook.Settings do
   @doc """
   Returns the current autosave path.
   """
-  @spec autosave_path() :: String.t() | nil
+  @spec autosave_path() :: String.t()
   def autosave_path() do
     case storage().fetch_key(:settings, "global", :autosave_path) do
       {:ok, value} -> value
@@ -98,4 +98,23 @@ defmodule Livebook.Settings do
       {:error, message} -> raise ArgumentError, "invalid S3 filesystem: #{message}"
     end
   end
+
+  @doc """
+  Returns whether the update check is enabled.
+  """
+  @spec update_check_enabled?() :: boolean()
+  def update_check_enabled?() do
+    case storage().fetch_key(:settings, "global", :update_check_enabled) do
+      {:ok, value} -> value
+      :error -> true
+    end
+  end
+
+  @doc """
+  Sets whether the update check is enabled.
+  """
+  @spec set_update_check_enabled(boolean()) :: :ok
+  def set_update_check_enabled(enabled) do
+    storage().insert(:settings, "global", update_check_enabled: enabled)
+  end
 end

lib/livebook/update_check.ex

@@ -0,0 +1,157 @@
+defmodule Livebook.UpdateCheck do
+  @moduledoc false
+
+  # Periodically checks for available Livebook update.
+
+  use GenServer
+
+  require Logger
+
+  @name __MODULE__
+  @timeout :infinity
+
+  @hour_in_ms 60 * 60 * 1000
+  @day_in_ms 24 * @hour_in_ms
+
+  @doc false
+  def start_link(_opts) do
+    GenServer.start_link(__MODULE__, {}, name: @name)
+  end
+
+  @doc """
+  Returns the latest Livebook version if it's more recent than the
+  current one.
+  """
+  @spec new_version() :: String.t() | nil
+  def new_version() do
+    GenServer.call(@name, :get_new_version, @timeout)
+  end
+
+  @doc """
+  Returns whether the update check is enabled.
+  """
+  @spec enabled?() :: boolean()
+  def enabled?() do
+    GenServer.call(@name, :get_enabled, @timeout)
+  end
+
+  @doc """
+  Sets whether the update check is enabled.
+  """
+  @spec set_enabled(boolean()) :: :ok
+  def set_enabled(enabled) do
+    GenServer.cast(@name, {:set_enabled, enabled})
+  end
+
+  @impl true
+  def init({}) do
+    state = %{
+      enabled: Livebook.Settings.update_check_enabled?(),
+      new_version: nil,
+      timer_ref: nil,
+      request_ref: nil
+    }
+
+    {:ok, schedule_check(state, 0)}
+  end
+
+  @impl true
+  def handle_cast({:set_enabled, enabled}, state) do
+    Livebook.Settings.set_update_check_enabled(enabled)
+    state = %{state | enabled: enabled}
+    state = state |> cancel_check() |> schedule_check(0)
+    {:noreply, state}
+  end
+
+  @impl true
+  def handle_call(:get_enabled, _from, state) do
+    {:reply, state.enabled, state}
+  end
+
+  @impl true
+  def handle_call(:get_new_version, _from, state) do
+    new_version = if state.enabled, do: state.new_version
+    {:reply, new_version, state}
+  end
+
+  @impl true
+  def handle_info(:check, state) do
+    task = Task.Supervisor.async_nolink(Livebook.TaskSupervisor, &fetch_latest_version/0)
+    {:noreply, %{state | request_ref: task.ref}}
+  end
+
+  def handle_info({ref, response}, %{request_ref: ref} = state) do
+    Process.demonitor(ref, [:flush])
+
+    state =
+      case response do
+        {:ok, version} ->
+          new_version = if newer?(version), do: version
+          state = %{state | new_version: new_version}
+          schedule_check(state, @day_in_ms)
+
+        {:error, error} ->
+          Logger.error("version check failed, #{error}")
+          schedule_check(state, @hour_in_ms)
+      end
+
+    {:noreply, %{state | request_ref: nil}}
+  end
+
+  def handle_info({:DOWN, ref, :process, _pid, reason}, %{request_ref: ref} = state) do
+    Logger.error("version check failed, reason: #{inspect(reason)}")
+    {:noreply, %{state | request_ref: nil} |> schedule_check(@hour_in_ms)}
+  end
+
+  def handle_info(_msg, state), do: {:noreply, state}
+
+  defp schedule_check(%{enabled: false} = state, _time), do: state
+
+  defp schedule_check(state, time) do
+    timer_ref = Process.send_after(self(), :check, time)
+    %{state | timer_ref: timer_ref}
+  end
+
+  defp cancel_check(%{timer_ref: nil} = state), do: state
+
+  defp cancel_check(state) do
+    if Process.cancel_timer(state.timer_ref) == false do
+      receive do
+        :check -> :ok
+      end
+    end
+
+    %{state | timer_ref: nil}
+  end
+
+  defp fetch_latest_version() do
+    url = "https://api.github.com/repos/livebook-dev/livebook/releases/latest"
+    headers = [{"accept", "application/vnd.github.v3+json"}]
+
+    case Livebook.Utils.HTTP.request(:get, url, headers: headers) do
+      {:ok, status, _headers, body} ->
+        with 200 <- status,
+             {:ok, data} <- Jason.decode(body),
+             %{"tag_name" => "v" <> version} <- data do
+          {:ok, version}
+        else
+          _ -> {:error, "unexpected response"}
+        end
+
+      {:error, reason} ->
+        {:error, "failed to make a request, reason: #{inspect(reason)}"}
+    end
+  end
+
+  defp newer?(version) do
+    current_version = Application.spec(:livebook, :vsn) |> List.to_string()
+    stable?(version) and Version.compare(current_version, version) == :lt
+  end
+
+  defp stable?(version) do
+    case Version.parse(version) do
+      {:ok, %{pre: []}} -> true
+      _ -> false
+    end
+  end
+end

lib/livebook_web/live/home_live.ex

@@ -26,6 +26,8 @@ defmodule LivebookWeb.HomeLive do
        sessions: sessions,
        notebook_infos: notebook_infos,
        page_title: "Livebook",
+       new_version: Livebook.UpdateCheck.new_version(),
+       update_instructions_url: Livebook.Config.update_instructions_url(),
        app_service_url: Livebook.Config.app_service_url(),
        memory: Livebook.SystemResources.memory()
      )}
@@ -39,9 +41,10 @@ defmodule LivebookWeb.HomeLive do
       <SidebarHelpers.sidebar>
         <SidebarHelpers.shared_home_footer socket={@socket} current_user={@current_user} />
       </SidebarHelpers.sidebar>
-      <div class="grow px-6 py-8 overflow-y-auto">
-        <div class="max-w-screen-lg w-full mx-auto px-4 pb-8 space-y-4">
-          <.memory_notification memory={@memory} app_service_url={@app_service_url} />
+      <div class="grow overflow-y-auto">
+        <.update_notification version={@new_version} instructions_url={@update_instructions_url} />
+        <.memory_notification memory={@memory} app_service_url={@app_service_url} />
+        <div class="max-w-screen-lg w-full mx-auto px-8 pt-8 pb-32 space-y-4">
           <div class="flex flex-col space-y-2 items-center pb-4 border-b border-gray-200
                       sm:flex-row sm:space-y-0 sm:justify-between">
             <div class="text-2xl text-gray-800 font-semibold">
@@ -157,18 +160,41 @@ defmodule LivebookWeb.HomeLive do
     end
   end
 
+  defp update_notification(%{version: nil} = assigns), do: ~H""
+
+  defp update_notification(assigns) do
+    ~H"""
+    <div class="px-2 py-2 bg-blue-200 text-gray-900 text-sm text-center">
+      <span>
+        Livebook v<%= @version %> available!
+        <%= if @instructions_url do %>
+          Check out the news on
+          <a class="font-medium border-b border-gray-900 hover:border-transparent" href="https://livebook.dev/" target="_blank">
+            livebook.dev
+          </a>
+          and follow the
+          <a class="font-medium border-b border-gray-900 hover:border-transparent" href={@instructions_url} target="_blank">
+            update instructions
+          </a>
+        <% else %>
+          Check out the news and installation steps on
+          <a class="font-medium border-b border-gray-900 hover:border-transparent" href="https://livebook.dev/" target="_blank">livebook.dev</a>
+        <% end %>
+        🚀
+      </span>
+    </div>
+    """
+  end
+
   defp memory_notification(assigns) do
     ~H"""
     <%= if @app_service_url && @memory.free < 30_000_000 do %>
-      <div class="flex justify-between items-center border-b border-gray-200 pb-4 text-gray-700">
-        <span class="flex items-end">
-          <.remix_icon icon="alarm-warning-line" class="text-xl mr-2" />
-          <span>
-          Less than 30 MB of memory left, consider adding more resources to
-          <a class="font-semibold" href={@app_service_url} target="_blank">the instance</a>
-          or closing <a class="font-semibold" href="#running-sessions">running sessions</a>.
-          </span>
-        </span>
+      <div class="px-2 py-2 bg-red-200 text-gray-900 text-sm text-center">
+        <.remix_icon icon="alarm-warning-line" class="align-text-bottom mr-0.5" />
+        Less than 30 MB of memory left, consider
+        <a class="font-medium border-b border-gray-900 hover:border-transparent" href={@app_service_url} target="_blank">adding more resources to the instance</a>
+        or closing
+        <a class="font-medium border-b border-gray-900 hover:border-transparent" href="#running-sessions">running sessions</a>
       </div>
     <% end %>
     """

lib/livebook_web/live/settings_live.ex

@@ -7,17 +7,16 @@ defmodule LivebookWeb.SettingsLive do
 
   @impl true
   def mount(_params, _session, socket) do
-    file_systems = Livebook.Settings.file_systems()
-
     {:ok,
      socket
      |> SidebarHelpers.shared_home_handlers()
      |> assign(
-       file_systems: file_systems,
+       file_systems: Livebook.Settings.file_systems(),
        autosave_path_state: %{
          file: autosave_dir(),
          dialog_opened?: false
        },
+       update_check_enabled: Livebook.UpdateCheck.enabled?(),
        page_title: "Livebook - Settings"
      )}
   end
@@ -45,9 +44,9 @@ defmodule LivebookWeb.SettingsLive do
 
           <!-- System details -->
           <div class="flex flex-col space-y-4">
-            <h1 class="text-xl text-gray-800 font-semibold">
+            <h2 class="text-xl text-gray-800 font-semibold">
               About
-            </h1>
+            </h2>
             <div class="flex items-center justify-between border border-gray-200 rounded-lg p-4">
               <div class="flex items-center space-x-12">
                 <%= if app_name = Livebook.Config.app_service_name() do %>
@@ -76,6 +75,18 @@ defmodule LivebookWeb.SettingsLive do
               <% end %>
             </div>
           </div>
+          <!-- Preferences -->
+          <div class="flex flex-col space-y-4">
+            <h2 class="text-xl text-gray-800 font-semibold">
+              Preferences
+            </h2>
+            <form phx-change="save" onsubmit="return false;">
+              <.switch_checkbox
+                name="update_check_enabled"
+                label="Show available Livebook updates"
+                checked={@update_check_enabled} />
+            </form>
+          </div>
           <!-- Autosave path configuration -->
           <div class="flex flex-col space-y-4">
             <div>
@@ -253,6 +264,12 @@ defmodule LivebookWeb.SettingsLive do
     {:noreply, assign(socket, file_systems: file_systems)}
   end
 
+  def handle_event("save", %{"update_check_enabled" => enabled}, socket) do
+    enabled = enabled == "true"
+    Livebook.UpdateCheck.set_enabled(enabled)
+    {:noreply, assign(socket, :update_check_enabled, enabled)}
+  end
+
   @impl true
   def handle_info({:file_systems_updated, file_systems}, socket) do
     {:noreply, assign(socket, file_systems: file_systems)}