Hack to disable Prometheus metrics by default

config/config.exs

@@ -636,7 +636,9 @@
 
 config :pleroma, Pleroma.Emails.NewUsersDigestEmail, enabled: false
 
-config :prometheus, Pleroma.Web.Endpoint.MetricsExporter, path: "/api/pleroma/app_metrics"
+config :prometheus, Pleroma.Web.Endpoint.MetricsExporter,
+  enabled: false,
+  path: "/api/pleroma/app_metrics"
 
 config :pleroma, Pleroma.ScheduledActivity,
   daily_user_limit: 25,

lib/pleroma/application.ex

@@ -135,23 +135,25 @@ def load_custom_modules do
   end
 
   defp setup_instrumenters do
-    require Prometheus.Registry
+    if Application.get_env(:prometheus, Pleroma.Web.Endpoint.MetricsExporter)[:enabled] do
+      require Prometheus.Registry
 
-    if Application.get_env(:prometheus, Pleroma.Repo.Instrumenter) do
-      :ok =
-        :telemetry.attach(
-          "prometheus-ecto",
-          [:pleroma, :repo, :query],
-          &Pleroma.Repo.Instrumenter.handle_event/4,
-          %{}
-        )
+      if Application.get_env(:prometheus, Pleroma.Repo.Instrumenter) do
+        :ok =
+          :telemetry.attach(
+            "prometheus-ecto",
+            [:pleroma, :repo, :query],
+            &Pleroma.Repo.Instrumenter.handle_event/4,
+            %{}
+          )
 
-      Pleroma.Repo.Instrumenter.setup()
+        Pleroma.Repo.Instrumenter.setup()
+      end
+
+      Pleroma.Web.Endpoint.MetricsExporter.setup()
+      Pleroma.Web.Endpoint.PipelineInstrumenter.setup()
+      Pleroma.Web.Endpoint.Instrumenter.setup()
     end
-
-    Pleroma.Web.Endpoint.MetricsExporter.setup()
-    Pleroma.Web.Endpoint.PipelineInstrumenter.setup()
-    Pleroma.Web.Endpoint.Instrumenter.setup()
   end
 
   defp cachex_children do