From 7f8a9329e566140f9f36cecac58b13097b7e0519 Mon Sep 17 00:00:00 2001
From: Mark Felder <feld@feld.me>
Date: Thu, 16 May 2024 16:03:05 -0400
Subject: [PATCH] Startup detection for configured MRF modules that are missing
 or incorrectly defined

---
 changelog.d/missing-mrfs.add            |  1 +
 lib/pleroma/application_requirements.ex | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 changelog.d/missing-mrfs.add

diff --git a/changelog.d/missing-mrfs.add b/changelog.d/missing-mrfs.add
new file mode 100644
index 000000000..6a17f9e1a
--- /dev/null
+++ b/changelog.d/missing-mrfs.add
@@ -0,0 +1 @@
+Startup detection for configured MRF modules that are missing or incorrectly defined
diff --git a/lib/pleroma/application_requirements.ex b/lib/pleroma/application_requirements.ex
index 819245481..8c0df64fc 100644
--- a/lib/pleroma/application_requirements.ex
+++ b/lib/pleroma/application_requirements.ex
@@ -28,6 +28,7 @@ def verify! do
     |> check_welcome_message_config!()
     |> check_rum!()
     |> check_repo_pool_size!()
+    |> check_mrfs()
     |> handle_result()
   end
 
@@ -234,4 +235,25 @@ defp check_filter(filter, command_required) do
       true
     end
   end
+
+  defp check_mrfs(:ok) do
+    mrfs = Config.get!([:mrf, :policies])
+
+    missing_mrfs =
+      Enum.reduce(mrfs, [], fn x, acc ->
+        if Code.ensure_compiled(x) do
+          acc
+        else
+          acc ++ [x]
+        end
+      end)
+
+    if Enum.empty?(missing_mrfs) do
+      :ok
+    else
+      {:error, "The following MRF modules are configured but missing: #{inspect(missing_mrfs)}"}
+    end
+  end
+
+  defp check_mrfs(result), do: result
 end