fix: Fix GenRpc to not try to connect to nodes that are not alive (#1525)

Author: edgurgel

lib/realtime/gen_rpc.ex

@@ -41,6 +41,23 @@ defmodule Realtime.GenRpc do
   @spec call(node, module, atom, list(any), keyword()) :: result
   def call(node, mod, func, args, opts)
       when is_atom(node) and is_atom(mod) and is_atom(func) and is_list(args) and is_list(opts) do
+    if node == node() or node in Node.list() do
+      do_call(node, mod, func, args, opts)
+    else
+      tenant_id = Keyword.get(opts, :tenant_id)
+
+      log_error(
+        "ErrorOnRpcCall",
+        %{target: node, mod: mod, func: func, error: :badnode},
+        project: tenant_id,
+        external_id: tenant_id
+      )
+
+      {:error, :rpc_error, :badnode}
+    end
+  end
+
+  defp do_call(node, mod, func, args, opts) do
     timeout = Keyword.get(opts, :timeout, default_rpc_timeout())
     tenant_id = Keyword.get(opts, :tenant_id)
     key = Keyword.get(opts, :key, nil)

mix.exs

@@ -4,7 +4,7 @@ defmodule Realtime.MixProject do
   def project do
     [
       app: :realtime,
-      version: "2.47.0",
+      version: "2.47.1",
       elixir: "~> 1.17.3",
       elixirc_paths: elixirc_paths(Mix.env()),
       start_permanent: Mix.env() == :prod,

test/realtime/gen_rpc_test.exs

@@ -172,6 +172,18 @@ defmodule Realtime.GenRpcTest do
                         mechanism: :gen_rpc
                       }}
     end
+
+    test "bad node" do
+      node = :"[email protected]"
+
+      log =
+        capture_log(fn ->
+          assert GenRpc.call(node, Map, :fetch, [%{a: 1}, :a], tenant_id: 123) == {:error, :rpc_error, :badnode}
+        end)
+
+      assert log =~
+               ~r/project=123 external_id=123 \[error\] ErrorOnRpcCall: %{+error: :badnode, mod: Map, func: :fetch, target: :"#{node}"/
+    end
   end
 
   describe "multicast/4" do