keyspace: return copied meta service groups

Signed-off-by: bufferflies <1045931706@qq.com>

Author: bufferflies

pkg/keyspace/meta_service_group.go

@@ -158,7 +158,11 @@ func (m *MetaServiceGroupManager) AttachEndpoints(keyspaceConfig map[string]stri
 func (m *MetaServiceGroupManager) GetGroups() map[string]string {
 	m.RLock()
 	defer m.RUnlock()
-	return m.metaServiceGroups
+	groups := make(map[string]string, len(m.metaServiceGroups))
+	for id, endpoints := range m.metaServiceGroups {
+		groups[id] = endpoints
+	}
+	return groups
 }
 
 // updateGroups updates currently available meta-service groups.

pkg/keyspace/meta_service_group_test.go

@@ -156,6 +156,17 @@ func (suite *metaServiceGroupTestSuite) TestUpdateEndpoints() {
 	re.Equal("foo.bar.local", config[MetaServiceGroupAddressesKey], "should read from updated metaServiceGroups map")
 }
 
+func (suite *metaServiceGroupTestSuite) TestGetGroupsReturnsCopy() {
+	re := suite.Require()
+	groups := suite.manager.GetGroups()
+	groups["etcd-group-0"] = "mutated"
+	delete(groups, "etcd-group-1")
+
+	currentGroups := suite.manager.GetGroups()
+	re.Equal(mockMetaServiceGroups()["etcd-group-0"], currentGroups["etcd-group-0"])
+	re.Equal(mockMetaServiceGroups()["etcd-group-1"], currentGroups["etcd-group-1"])
+}
+
 func (suite *metaServiceGroupTestSuite) TestUpdateEndpointsAndUpdateAssignment() {
 	re := suite.Require()
 	// Assign to some existing group