feat(deployer): display monitored application logo

apps/deployer/lib/deployer/status.ex

@@ -36,7 +36,8 @@ defmodule Deployer.Status do
           certificates: [],
           otp_version: String.t() | nil,
           elixir_version: String.t() | nil,
-          phoenix_version: String.t() | nil
+          phoenix_version: String.t() | nil,
+          logo: String.t() | nil
         }
 
   defstruct name: nil,
@@ -63,7 +64,8 @@ defmodule Deployer.Status do
             certificates: [],
             otp_version: nil,
             elixir_version: nil,
-            phoenix_version: nil
+            phoenix_version: nil,
+            logo: nil
 
   @behaviour Deployer.Status.Adapter
 

apps/deployer/lib/deployer/status/application.ex

@@ -12,6 +12,7 @@ defmodule Deployer.Status.Application do
   alias Deployer.Monitor
   alias Deployer.Status
   alias Deployer.Status.Endpoints
+  alias Deployer.Status.Logo
   alias Deployer.Status.Versions
   alias Foundation.Catalog
   alias Foundation.Certificates.PublicKey
@@ -384,7 +385,8 @@ defmodule Deployer.Status.Application do
       monitoring: monitoring,
       otp_version: node_otp_version(node),
       elixir_version: node_elixir_version(node),
-      phoenix_version: node_phoenix_version(node)
+      phoenix_version: node_phoenix_version(node),
+      logo: node_logo(node, otp == :connected, name)
     }
   end
 
@@ -452,4 +454,15 @@ defmodule Deployer.Status.Application do
       Versions.phoenix_version(node)
     end
   end
+
+  defp node_logo(node, connected?, name) do
+    if connected? do
+      cache_in_process({node, :logo}) do
+        Logo.image(node, name)
+      end
+    else
+      Process.delete({node, :logo})
+      nil
+    end
+  end
 end

apps/deployer/lib/deployer/status/logo.ex

@@ -0,0 +1,75 @@
+defmodule Deployer.Status.Logo do
+  @moduledoc """
+  Reads the logo of a monitored application so it can be shown in the UI.
+
+  The logo is fetched over RPC from the monitored node, at
+  `priv/static/images/logo.svg` inside the application's own `priv`
+  directory, and returned as a base64 `data:` URI ready to be used as an
+  `<img>` source.
+
+  Lookup is best effort and never prevents an application from being
+  rendered. It distinguishes an application that answered and has no logo,
+  which is a definitive answer, from a lookup that could not be performed
+  because the node did not reply, so that a transient failure is not
+  remembered as a missing logo.
+  """
+
+  alias Foundation.Rpc
+
+  @rpc_timeout 1_000
+
+  ### ==========================================================================
+  ### Public APIs
+  ### ==========================================================================
+
+  @doc """
+  Return the logo of the application `name` running on `node` as a base64
+  `data:` URI.
+
+  Returns `{:ok, nil}` when the node answered but has no `logo.svg`, which
+  is a definitive answer and safe for the caller to cache.
+
+  Returns `:error` when the question could not be answered at all, because
+  the name is not a known application or the node did not reply. The caller
+  is expected to treat this as "unknown for now" and ask again later rather
+  than remembering the absence of a logo.
+  """
+  @spec image(node :: node(), name :: String.t()) :: {:ok, String.t() | nil} | :error
+  def image(node, name) do
+    with {:ok, app} <- existing_atom(name),
+         {:ok, priv_dir} <- app_priv_dir(node, app),
+         path <- logo_path(priv_dir),
+         {:ok, binary} <- Rpc.call(node, :file, :read_file, [path], @rpc_timeout) do
+      {:ok, "data:image/svg+xml;base64," <> Base.encode64(binary)}
+    else
+      :error -> :error
+      _ -> {:ok, nil}
+    end
+  end
+
+  ### ==========================================================================
+  ### Private functions
+  ### ==========================================================================
+
+  # The application name only maps to an atom when the application is known
+  # to this node, so an unknown name is a normal miss rather than a failure.
+  defp existing_atom(name) do
+    {:ok, String.to_existing_atom(name)}
+  rescue
+    ArgumentError -> :error
+  end
+
+  defp app_priv_dir(node, app) do
+    case Rpc.call(node, :code, :priv_dir, [app], @rpc_timeout) do
+      priv_dir when is_list(priv_dir) ->
+        {:ok, to_string(priv_dir)}
+
+      _err ->
+        :error
+    end
+  end
+
+  defp logo_path(priv_dir) do
+    Path.join([priv_dir, "static", "images", "logo.svg"])
+  end
+end

apps/deployer/test/status/logo_test.exs

@@ -0,0 +1,76 @@
+defmodule Deployer.Status.LogoTest do
+  use ExUnit.Case, async: false
+
+  import Mox
+
+  alias Deployer.Status.Logo
+
+  setup [
+    :set_mox_global,
+    :verify_on_exit!
+  ]
+
+  @node :"myelixir-abc123@nohost"
+  @name "myelixir"
+  @app :myelixir
+  @priv_dir ~c"/opt/myelixir/lib/myelixir-1.0.0/priv"
+  @svg ~s(<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64"></svg>)
+
+  test "image/2 returns the logo as a base64 svg data uri" do
+    Foundation.RpcMock
+    |> expect(:call, fn @node, :code, :priv_dir, [@app], _timeout -> @priv_dir end)
+    |> expect(:call, fn @node, :file, :read_file, [_path], _timeout -> {:ok, @svg} end)
+
+    assert {:ok, "data:image/svg+xml;base64," <> encoded} = Logo.image(@node, @name)
+    assert {:ok, @svg} = Base.decode64(encoded)
+  end
+
+  test "image/2 reads logo.svg from the application's own priv directory" do
+    Foundation.RpcMock
+    |> expect(:call, fn @node, :code, :priv_dir, [@app], _timeout -> @priv_dir end)
+    |> expect(:call, fn @node, :file, :read_file, [path], _timeout ->
+      assert path == "/opt/myelixir/lib/myelixir-1.0.0/priv/static/images/logo.svg"
+      {:ok, @svg}
+    end)
+
+    assert {:ok, _data_uri} = Logo.image(@node, @name)
+  end
+
+  test "image/2 returns nil when the application has no logo.svg" do
+    Foundation.RpcMock
+    |> expect(:call, fn @node, :code, :priv_dir, [@app], _timeout -> @priv_dir end)
+    |> expect(:call, fn @node, :file, :read_file, [_path], _timeout -> {:error, :enoent} end)
+
+    assert {:ok, nil} = Logo.image(@node, @name)
+  end
+
+  test "image/2 errors when the application is not loaded on the node" do
+    Foundation.RpcMock
+    |> expect(:call, fn @node, :code, :priv_dir, [@app], _timeout -> {:error, :bad_name} end)
+
+    assert :error = Logo.image(@node, @name)
+  end
+
+  test "image/2 errors when the node is unreachable" do
+    Foundation.RpcMock
+    |> expect(:call, fn @node, :code, :priv_dir, [@app], _timeout -> {:badrpc, :nodedown} end)
+
+    assert :error = Logo.image(@node, @name)
+  end
+
+  test "image/2 errors for an unknown application name without calling the node" do
+    # verify_on_exit! fails the test if the unknown name reaches the node
+    assert :error = Logo.image(@node, "unknown_#{System.unique_integer([:positive])}")
+  end
+
+  test "image/2 separates a node with no logo from a node that did not answer" do
+    # only the first is a definitive answer, so only it is safe for the caller to cache
+    Foundation.RpcMock
+    |> expect(:call, fn @node, :code, :priv_dir, [@app], _timeout -> @priv_dir end)
+    |> expect(:call, fn @node, :file, :read_file, [_path], _timeout -> {:error, :enoent} end)
+    |> expect(:call, fn @node, :code, :priv_dir, [@app], _timeout -> {:badrpc, :nodedown} end)
+
+    assert {:ok, nil} = Logo.image(@node, @name)
+    assert :error = Logo.image(@node, @name)
+  end
+end

apps/deployex_web/lib/deployex_web/live/components/application_card.ex

@@ -35,10 +35,12 @@ defmodule DeployexWeb.Components.ApplicationCard do
           <!-- App Header -->
           <div class="gap-6">
             <div class="flex items-center gap-6 mb-8">
-              <div class="avatar">
-                <div class="w-20 h-20 rounded-xl bg-base-200/30 flex items-center justify-center">
-                  <img src={"/images/#{@application.language}.ico"} alt="" class="w-12 h-12" />
-                </div>
+              <div class="w-20 h-20 shrink-0 rounded-xl bg-base-200/30 flex items-center justify-center">
+                <img
+                  src={@application.logo || "/images/#{@application.language}.ico"}
+                  alt=""
+                  class="w-full h-full object-contain"
+                />
               </div>
               <div class="flex-1">
                 <h1 class="text-3xl font-bold text-base-content mb-2">{@application.name}</h1>