Merge pull request #171 from appunite/feat/lazy-sidecar-startup

feat: accept traffic before sidecars are ready on cold start

Author: emilwojtaszek

cloud-run/service.yaml

@@ -13,7 +13,6 @@ spec:
         autoscaling.knative.dev/minScale: "0"
         autoscaling.knative.dev/maxScale: "2"
         run.googleapis.com/execution-environment: gen2
-        run.googleapis.com/container-dependencies: '{"ksef-hub":["pdf-renderer","invoice-extractor","invoice-classifier"]}'
         run.googleapis.com/startup-cpu-boost: "true"
     spec:
       containerConcurrency: 80

config/test.exs

@@ -45,6 +45,8 @@ config :ksef_hub, :invoice_classifier, KsefHub.InvoiceClassifier.Mock
 config :ksef_hub, :invoice_extractor, KsefHub.InvoiceExtractor.Mock
 config :ksef_hub, :emoji_generator, KsefHub.EmojiGenerator.Mock
 
+config :ksef_hub, extractor_retry_delay_ms: 0
+
 config :ksef_hub,
   invoice_extractor_req_options: [
     plug: {Req.Test, KsefHub.InvoiceExtractor.Client},

lib/ksef_hub/invoice_extractor/client.ex

@@ -11,6 +11,7 @@ defmodule KsefHub.InvoiceExtractor.Client do
   require Logger
 
   @receive_timeout 120_000
+  @max_retries 3
   @output_schema Path.join(__DIR__, "output_schema.json")
                  |> File.read!()
                  |> Jason.decode!()
@@ -24,7 +25,7 @@ defmodule KsefHub.InvoiceExtractor.Client do
          {:ok, token} <- fetch_token() do
       filename = opts |> Keyword.get(:filename, "invoice.pdf") |> sanitize_filename()
       context = Keyword.get(opts, :context)
-      do_extract(base_url, token, pdf_binary, filename, context)
+      do_extract(base_url, token, pdf_binary, filename, context, @max_retries)
     end
   end
 
@@ -51,16 +52,32 @@ defmodule KsefHub.InvoiceExtractor.Client do
     end
   end
 
-  @spec do_extract(String.t(), String.t(), binary(), String.t(), String.t() | nil) ::
+  @spec do_extract(
+          String.t(),
+          String.t(),
+          binary(),
+          String.t(),
+          String.t() | nil,
+          non_neg_integer()
+        ) ::
           {:ok, map()} | {:error, term()}
-  defp do_extract(base_url, token, pdf_binary, filename, context) do
-    case base_url
-         |> build_req()
-         |> Req.post(
-           url: "/extract",
-           form_multipart: build_form_parts(pdf_binary, filename, context),
-           headers: [{"authorization", "Bearer #{token}"}]
-         ) do
+  defp do_extract(base_url, token, pdf_binary, filename, context, retries) do
+    result =
+      base_url
+      |> build_req()
+      |> Req.post(
+        url: "/extract",
+        form_multipart: build_form_parts(pdf_binary, filename, context),
+        headers: [{"authorization", "Bearer #{token}"}]
+      )
+
+    case result do
+      {:error, %Req.TransportError{reason: :econnrefused}} when retries > 0 ->
+        delay = Application.get_env(:ksef_hub, :extractor_retry_delay_ms, 1_000)
+        Logger.warning("Invoice extractor not ready, retrying in #{delay}ms (#{retries} left)")
+        Process.sleep(delay)
+        do_extract(base_url, token, pdf_binary, filename, context, retries - 1)
+
       {:ok, %{status: 200, body: %{"success" => true, "data" => data}}} when is_map(data) ->
         {:ok, data}
 
@@ -69,7 +86,6 @@ defmodule KsefHub.InvoiceExtractor.Client do
 
       {:ok, %{status: status}} ->
         Logger.error("Invoice extractor returned #{status} for /extract")
-
         {:error, {:extractor_error, status}}
 
       {:error, %{__struct__: struct_name} = reason} ->

lib/ksef_hub/service_health.ex

@@ -15,12 +15,28 @@ defmodule KsefHub.ServiceHealth do
   """
   @spec check_all() :: results()
   def check_all do
-    services = [
+    check_services([
       {:pdf_renderer, &pdf_renderer().health/0},
       {:invoice_extractor, &invoice_extractor().health/0},
       {:invoice_classifier, &invoice_classifier().health/0}
-    ]
+    ])
+  end
+
+  @doc """
+  Warms the sidecars required for PDF upload processing (extractor + classifier).
+
+  Called on the upload LiveView mount to use idle file-browsing time productively.
+  """
+  @spec warm_upload_sidecars() :: results()
+  def warm_upload_sidecars do
+    check_services([
+      {:invoice_extractor, &invoice_extractor().health/0},
+      {:invoice_classifier, &invoice_classifier().health/0}
+    ])
+  end
 
+  @spec check_services([{atom(), (-> {:ok, map()} | {:error, term()})}]) :: results()
+  defp check_services(services) do
     services
     |> Enum.map(fn {name, check_fn} ->
       {name, Task.async(fn -> safe_check(check_fn) end)}

lib/ksef_hub_web/live/invoice_live/show.ex

@@ -106,7 +106,9 @@ defmodule KsefHubWeb.InvoiceLive.Show do
            payment_status: payment_status,
            public_link: public_link,
            invoice_payment_requests: invoice_payment_requests,
-           html_preview: generate_preview(invoice),
+           html_preview: nil,
+           preview_ref: nil,
+           preview_loading: false,
            categories: Invoices.list_categories(company.id),
            editing: auto_edit && can_mutate,
            edit_form: build_edit_form(invoice),
@@ -128,10 +130,27 @@ defmodule KsefHubWeb.InvoiceLive.Show do
            tag_confidence_threshold: InvoiceClassifier.tag_confidence_threshold()
          )
          |> stream(:activity_log, activity_entries)
+         |> start_preview_task(invoice)
          |> refresh_tabs()}
     end
   end
 
+  @spec start_preview_task(Phoenix.LiveView.Socket.t(), Invoice.t()) ::
+          Phoenix.LiveView.Socket.t()
+  defp start_preview_task(socket, %{xml_file: %{content: content}} = invoice)
+       when is_binary(content) and content != "" do
+    if connected?(socket) do
+      task =
+        Task.Supervisor.async_nolink(KsefHub.TaskSupervisor, fn -> generate_preview(invoice) end)
+
+      assign(socket, preview_ref: task.ref, preview_loading: true)
+    else
+      socket
+    end
+  end
+
+  defp start_preview_task(socket, _invoice), do: socket
+
   @spec refresh_tabs(Phoenix.LiveView.Socket.t()) :: Phoenix.LiveView.Socket.t()
   defp refresh_tabs(socket), do: assign(socket, :visible_tabs, visible_tabs(socket.assigns))
 
@@ -845,6 +864,16 @@ defmodule KsefHubWeb.InvoiceLive.Show do
      |> put_flash(:error, "Re-extraction crashed. Please try again.")}
   end
 
+  def handle_info({ref, html}, %{assigns: %{preview_ref: ref}} = socket) when is_reference(ref) do
+    Process.demonitor(ref, [:flush])
+    {:noreply, assign(socket, html_preview: html, preview_ref: nil, preview_loading: false)}
+  end
+
+  def handle_info({:DOWN, ref, :process, _pid, _reason}, %{assigns: %{preview_ref: ref}} = socket)
+      when is_reference(ref) do
+    {:noreply, assign(socket, preview_ref: nil, preview_loading: false)}
+  end
+
   def handle_info({:new_activity, audit_log}, socket) do
     {:noreply,
      socket
@@ -1270,6 +1299,12 @@ defmodule KsefHubWeb.InvoiceLive.Show do
         <h2 class="mb-2 text-xs font-semibold uppercase tracking-wider text-muted-foreground">
           Preview
         </h2>
+        <div
+          :if={@preview_loading}
+          class="flex items-center justify-center flex-1 min-h-[600px] text-muted-foreground text-sm"
+        >
+          Loading preview&hellip;
+        </div>
         <div
           :if={@html_preview}
           class="border border-border rounded-lg overflow-hidden flex-1 min-h-[600px]"
@@ -1283,7 +1318,7 @@ defmodule KsefHubWeb.InvoiceLive.Show do
           </iframe>
         </div>
         <div
-          :if={!@html_preview && @invoice.pdf_file}
+          :if={!@preview_loading && !@html_preview && @invoice.pdf_file}
           class="border border-border rounded-lg overflow-hidden flex-1 min-h-[600px]"
         >
           <iframe
@@ -1294,7 +1329,7 @@ defmodule KsefHubWeb.InvoiceLive.Show do
           </iframe>
         </div>
         <p
-          :if={!@html_preview && !@invoice.pdf_file}
+          :if={!@preview_loading && !@html_preview && !@invoice.pdf_file}
           class="text-muted-foreground text-sm"
         >
           No preview available. XML content may be missing.

lib/ksef_hub_web/live/invoice_live/upload.ex

@@ -12,6 +12,7 @@ defmodule KsefHubWeb.InvoiceLive.Upload do
   alias KsefHub.Authorization
   alias KsefHub.Companies.Company
   alias KsefHub.Invoices
+  alias KsefHub.ServiceHealth
 
   import KsefHubWeb.UploadHelpers, only: [format_bytes: 1, upload_error_to_string: 1]
 
@@ -20,6 +21,12 @@ defmodule KsefHubWeb.InvoiceLive.Upload do
   @spec mount(map(), map(), Phoenix.LiveView.Socket.t()) ::
           {:ok, Phoenix.LiveView.Socket.t()}
   def mount(_params, _session, socket) do
+    if connected?(socket) do
+      Task.Supervisor.start_child(KsefHub.TaskSupervisor, fn ->
+        ServiceHealth.warm_upload_sidecars()
+      end)
+    end
+
     {:ok,
      socket
      |> assign(page_title: "Upload PDF Invoice", uploading: false, upload_refs: MapSet.new())

test/ksef_hub/invoice_extractor/client_test.exs

@@ -60,6 +60,27 @@ defmodule KsefHub.InvoiceExtractor.ClientTest do
                Client.extract("pdf data", filename: "test.pdf")
     end
 
+    test "retries on econnrefused and succeeds when service becomes available" do
+      setup_extractor_config()
+
+      {:ok, attempts} = Agent.start_link(fn -> 0 end)
+
+      Req.Test.stub(Client, fn conn ->
+        attempt = Agent.get_and_update(attempts, fn n -> {n, n + 1} end)
+
+        if attempt == 0 do
+          Req.Test.transport_error(conn, :econnrefused)
+        else
+          Req.Test.json(conn, %{"seller_nip" => "1234567890"})
+        end
+      end)
+
+      assert {:ok, %{"seller_nip" => "1234567890"}} =
+               Client.extract("pdf data", filename: "test.pdf")
+
+      assert Agent.get(attempts, & &1) == 2
+    end
+
     test "sends context as form field when provided in opts" do
       setup_extractor_config()
 

test/ksef_hub_web/live/invoice_live/show_test.exs

@@ -76,8 +76,10 @@ defmodule KsefHubWeb.InvoiceLive.ShowTest do
         {:ok, "<html>preview</html>"}
       end)
 
-      {:ok, _view, html} = live(conn, ~p"/c/#{company.id}/invoices/#{invoice.id}")
-      assert html =~ "preview"
+      {:ok, view, _html} = live(conn, ~p"/c/#{company.id}/invoices/#{invoice.id}")
+      # Allow the async preview task to complete
+      :timer.sleep(100)
+      assert render(view) =~ "preview"
     end
   end
 

test/ksef_hub_web/live/invoice_live/upload_test.exs

@@ -14,6 +14,12 @@ defmodule KsefHubWeb.InvoiceLive.UploadTest do
   setup :set_mox_global
   setup :verify_on_exit!
 
+  setup do
+    stub(KsefHub.InvoiceExtractor.Mock, :health, fn -> {:ok, %{"status" => "ok"}} end)
+    stub(KsefHub.InvoiceClassifier.Mock, :health, fn -> {:ok, %{"status" => "ok"}} end)
+    :ok
+  end
+
   setup %{conn: conn} do
     {:ok, user} =
       Accounts.get_or_create_google_user(%{