module: Break dependency cycles when loading config correctly

See #832

Author: foxcpp

framework/module/registry.go

@@ -105,11 +105,11 @@ func (r *Registry) ensureInitialized(name string, entry *registryEntry) error {
 
 	r.logger.DebugMsg("module configure",
 		"mod_name", entry.Mod.Name(), "inst_name", entry.Mod.InstanceName())
+	r.initialized[name] = struct{}{}
 	err := entry.LazyInit()
 	if err != nil {
 		return err
 	}
-	r.initialized[name] = struct{}{}
 
 	return nil
 }

tests/modules_test.go

@@ -0,0 +1,63 @@
+//go:build integration
+
+/*
+Maddy Mail Server - Composable all-in-one email server.
+Copyright © 2019-2020 Max Mazurov <fox.cpp@disroot.org>, Maddy Mail Server contributors
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package tests_test
+
+import (
+	"testing"
+
+	"github.com/foxcpp/maddy/tests"
+)
+
+func TestConfigCycle(tt *testing.T) {
+	tt.Parallel()
+
+	t := tests.NewT(tt)
+	t.DNS(nil)
+	t.Config(`
+		hostname mx.maddy.test
+
+		msgpipeline local_routing {
+			destination maddy.test {
+				deliver_to dummy
+			}
+			default_destination {
+				deliver_to &outbound_queue
+			}
+		}
+
+		target.queue outbound_queue {
+			target dummy
+			autogenerated_msg_domain maddy.test
+			bounce {
+				deliver_to &local_routing
+			}
+		}
+
+		smtp tcp://127.0.0.1:1443 {
+			tls off
+
+			deliver_to &local_routing
+		}
+    `)
+	t.Run(1)
+
+	t.Close()
+}