fix: Invalidate Cache on delete (#795)

Invalidates Tenant Cache on delete.

This needs to be done because if the client connects within the range of normal cache invalidation they will end up creating replication slot which will leave the database with a replication slot that will not be used and potentially block maintenance operations.

lib/realtime_web/controllers/tenant_controller.ex

@@ -6,6 +6,7 @@ defmodule RealtimeWeb.TenantController do
 
   alias Realtime.Api
   alias Realtime.Api.Tenant
+  alias Realtime.Tenants.Cache
   alias Realtime.Helpers
   alias Realtime.PostgresCdc
   alias Realtime.Tenants
@@ -193,6 +194,7 @@ defmodule RealtimeWeb.TenantController do
           PostgresCdc.stop_all(tenant)
           Helpers.replication_slot_teardown(tenant)
           Api.delete_tenant_by_external_id(tenant_id)
+          Cache.invalidate_tenant_cache(tenant_id)
         end)
     end
 

mix.exs

@@ -4,7 +4,7 @@ defmodule Realtime.MixProject do
   def project do
     [
       app: :realtime,
-      version: "2.25.67",
+      version: "2.25.68",
       elixir: "~> 1.14.0",
       elixirc_paths: elixirc_paths(Mix.env()),
       start_permanent: Mix.env() == :prod,

test/realtime_web/controllers/tenant_controller_test.exs

@@ -9,6 +9,7 @@ defmodule RealtimeWeb.TenantControllerTest do
 
   alias Realtime.Api.Tenant
   alias Realtime.Helpers
+  alias Realtime.Tenants.Cache
   alias RealtimeWeb.ChannelsAuthorization
   alias RealtimeWeb.JwtVerification
 
@@ -138,6 +139,8 @@ defmodule RealtimeWeb.TenantControllerTest do
 
     test "deletes chosen tenant", %{conn: conn, tenant: tenant} do
       with_mock JwtVerification, verify: fn _token, _secret -> {:ok, %{}} end do
+        assert Cache.get_tenant_by_external_id(tenant.external_id)
+
         {:ok, db_conn} = Helpers.check_tenant_connection(tenant, "realtime_test")
 
         assert %{rows: [["supabase_realtime_replication_slot"]]} =
@@ -159,7 +162,11 @@ defmodule RealtimeWeb.TenantControllerTest do
              ]}
           )
 
-        {:ok, _} = Postgrex.query(db_conn, "SELECT slot_name FROM pg_replication_slots", [])
+        {:ok, %{rows: []}} =
+          Postgrex.query(db_conn, "SELECT slot_name FROM pg_replication_slots", [])
+
+        refute Cache.get_tenant_by_external_id(tenant.external_id)
+
         conn = get(conn, Routes.tenant_path(conn, :show, tenant.external_id))
         assert response(conn, 404)
       end