Discarded discovery events to be recorded (#3040)

lib/trento/discovery.ex

@@ -32,8 +32,9 @@ defmodule Trento.Discovery do
   @spec handle(map) :: :ok | {:error, any}
   def handle(event) do
     with {:ok, commands} <- do_handle(event),
-         {:ok, _} <- store_discovery_event(event) do
-      dispatch(commands)
+         {:ok, _} <- store_discovery_event(event),
+         :ok <- dispatch(commands) do
+      :ok
     else
       {:error, reason} = error ->
         Logger.error("Failed to handle discovery event: #{inspect(reason)}")

test/support/factory.ex

@@ -902,6 +902,20 @@ defmodule Trento.Factory do
     }
   end
 
+  def host_discovery_event_factory do
+    %{
+      "hostname" => Faker.StarWars.character(),
+      "ip_addresses" => [Faker.Internet.ip_v4_address()],
+      "agent_version" => Faker.App.semver(),
+      "cpu_count" => Enum.random(1..16),
+      "total_memory_mb" => Enum.random(1..128),
+      "socket_count" => Enum.random(1..16),
+      "os_version" => Faker.App.semver(),
+      "installation_source" => Enum.random(["community", "suse", "unknown"]),
+      "fully_qualified_domain_name" => Faker.Internet.domain_name()
+    }
+  end
+
   def software_updates_discovery_health_changed_event_factory do
     SoftwareUpdatesHealthChanged.new!(%{
       host_id: Faker.UUID.v4(),

test/trento/discovery_test.exs

@@ -2,6 +2,8 @@ defmodule Trento.DiscoveryTest do
   use ExUnit.Case
   use Trento.DataCase
 
+  import Mox
+
   import Trento.Factory
 
   alias Trento.Discovery
@@ -121,4 +123,25 @@ defmodule Trento.DiscoveryTest do
       %DiscardedDiscoveryEvent{payload: ^event}
     ] = discarded_events
   end
+
+  test "should discard discovery events when the dispatch action fails" do
+    error = :any_error
+
+    event = %{
+      "agent_id" => Faker.UUID.v4(),
+      "discovery_type" => "host_discovery",
+      "payload" => build(:host_discovery_event)
+    }
+
+    expect(Trento.Commanded.Mock, :dispatch, fn _ ->
+      {:error, error}
+    end)
+
+    {:error, ^error} = Discovery.handle(event)
+
+    [discarded_event] = Trento.Repo.all(DiscardedDiscoveryEvent)
+
+    assert %DiscardedDiscoveryEvent{payload: ^event} =
+             discarded_event
+  end
 end

test/trento_web/controllers/v1/discovery_controller_test.exs

@@ -1,6 +1,14 @@
 defmodule TrentoWeb.V1.DiscoveryControllerTest do
   use TrentoWeb.ConnCase, async: true
 
+  import Trento.DiscoveryFixturesHelper
+
+  import Mox
+
+  alias Trento.Discovery
+
+  alias Trento.Discovery.DiscardedDiscoveryEvent
+
   describe "discovery" do
     test "collect action should return an unprocessable entity error when the event is unknown",
          %{conn: conn} do
@@ -32,5 +40,27 @@ defmodule TrentoWeb.V1.DiscoveryControllerTest do
       })
       |> json_response(202)
     end
+
+    test "collect action discards application instance registrations when the associated database does not exists",
+         %{conn: conn} do
+      body =
+        load_discovery_event_fixture("sap_system_discovery_application")
+
+      expect(Trento.Commanded.Mock, :dispatch, fn _ ->
+        {:error, :any_error}
+      end)
+
+      %{status: status} =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/v1/collect", body)
+
+      assert status != 202
+
+      [discarded_event] = Discovery.get_discarded_discovery_events(1)
+
+      assert %DiscardedDiscoveryEvent{payload: ^body, reason: "[:any_error]"} =
+               discarded_event
+    end
   end
 end