Trim root zone indicator from server address (#97)

server/connector.go

@@ -177,7 +177,10 @@ func (c *connectorImpl) findAndConnectBackend(ctx context.Context, frontendConn
 	}
 
 	if backendHostPort == "" {
-		logrus.WithField("serverAddress", serverAddress).Warn("Unable to find registered backend")
+		logrus.
+			WithField("serverAddress", serverAddress).
+			WithField("resolvedHost", resolvedHost).
+			Warn("Unable to find registered backend")
 		c.metrics.Errors.With("type", "missing_backend").Add(1)
 		return
 	}

server/routes.go

@@ -170,7 +170,9 @@ func (r *routesImpl) FindBackendForServerAddress(ctx context.Context, serverAddr
 
 	addressParts := strings.Split(serverAddress, "\x00")
 
-	address := strings.ToLower(addressParts[0])
+	address := strings.ToLower(
+		// trim the root zone indicator, see https://en.wikipedia.org/wiki/Fully_qualified_domain_name
+		strings.TrimSuffix(addressParts[0], "."))
 
 	if r.mappings != nil {
 		if mapping, exists := r.mappings[address]; exists {

server/routes_test.go

@@ -41,6 +41,26 @@ func Test_routesImpl_FindBackendForServerAddress(t *testing.T) {
 			},
 			want: "backend:25566",
 		},
+		{
+			name: "root zone indicator",
+			mapping: mapping{
+				serverAddress: "my.domain", backend: "backend:25566",
+			},
+			args: args{
+				serverAddress: "my.domain.",
+			},
+			want: "backend:25566",
+		},
+		{
+			name: "root zone indicator and forge",
+			mapping: mapping{
+				serverAddress: "forge.my.domain", backend: "backend:25566",
+			},
+			args: args{
+				serverAddress: "forge.my.domain.\x00FML2\x00",
+			},
+			want: "backend:25566",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {