keyspace: add keyspace util func and ut (pingcap#41353)

ref pingcap#41354

keyspace/BUILD.bazel

@@ -1,12 +1,24 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "keyspace",
     srcs = ["keyspace.go"],
     importpath = "github.com/pingcap/tidb/keyspace",
     visibility = ["//visibility:public"],
     deps = [
+        "//config",
         "@com_github_pingcap_kvproto//pkg/kvrpcpb",
         "@com_github_tikv_client_go_v2//tikv",
     ],
 )
+
+go_test(
+    name = "keyspace_test",
+    srcs = ["keyspace_test.go"],
+    embed = [":keyspace"],
+    flaky = True,
+    deps = [
+        "//config",
+        "@com_github_stretchr_testify//suite",
+    ],
+)

keyspace/keyspace.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
+	"github.com/pingcap/tidb/config"
 	"github.com/tikv/client-go/v2/tikv"
 )
 
@@ -36,3 +37,14 @@ func MakeKeyspaceEtcdNamespace(c tikv.Codec) string {
 	}
 	return fmt.Sprintf(tidbKeyspaceEtcdPathPrefix+"%d", c.GetKeyspaceID())
 }
+
+// GetKeyspaceNameBySettings is used to get Keyspace name setting.
+func GetKeyspaceNameBySettings() (keyspaceName string) {
+	keyspaceName = config.GetGlobalKeyspaceName()
+	return keyspaceName
+}
+
+// IsKeyspaceNameEmpty is used to determine whether keyspaceName is set.
+func IsKeyspaceNameEmpty(keyspaceName string) bool {
+	return keyspaceName == ""
+}

keyspace/keyspace_test.go

@@ -0,0 +1,59 @@
+// Copyright 2021 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package keyspace
+
+import (
+	"testing"
+
+	"github.com/pingcap/tidb/config"
+	"github.com/stretchr/testify/suite"
+)
+
+type keyspaceSuite struct {
+	suite.Suite
+}
+
+func TestSetKeyspaceName(t *testing.T) {
+	suite.Run(t, new(keyspaceSuite))
+}
+
+func (k *keyspaceSuite) TearDownTest() {
+	// Clear keyspace setting
+	conf := config.GetGlobalConfig()
+	conf.KeyspaceName = ""
+	config.StoreGlobalConfig(conf)
+}
+
+func (k *keyspaceSuite) TestSetKeyspaceNameInConf() {
+	keyspaceNameInCfg := "test_keyspace_cfg"
+
+	// Set KeyspaceName in conf
+	c1 := config.GetGlobalConfig()
+	c1.KeyspaceName = keyspaceNameInCfg
+
+	getKeyspaceName := GetKeyspaceNameBySettings()
+
+	// Check the keyspaceName which get from GetKeyspaceNameBySettings, equals keyspaceNameInCfg which is in conf.
+	// The cfg.keyspaceName get higher weights than KEYSPACE_NAME in system env.
+	k.Equal(keyspaceNameInCfg, getKeyspaceName)
+	k.Equal(false, IsKeyspaceNameEmpty(getKeyspaceName))
+}
+
+func (k *keyspaceSuite) TestNoKeyspaceNameSet() {
+	getKeyspaceName := GetKeyspaceNameBySettings()
+
+	k.Equal("", getKeyspaceName)
+	k.Equal(true, IsKeyspaceNameEmpty(getKeyspaceName))
+}

tidb-server/BUILD.bazel

@@ -13,6 +13,7 @@ go_library(
         "//domain/infosync",
         "//executor",
         "//extension",
+        "//keyspace",
         "//kv",
         "//metrics",
         "//parser/mysql",

tidb-server/main.go

@@ -38,6 +38,7 @@ import (
 	"github.com/pingcap/tidb/domain/infosync"
 	"github.com/pingcap/tidb/executor"
 	"github.com/pingcap/tidb/extension"
+	"github.com/pingcap/tidb/keyspace"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/metrics"
 	"github.com/pingcap/tidb/parser/mysql"
@@ -232,7 +233,7 @@ func main() {
 	setupBinlogClient()
 	setupMetrics()
 
-	keyspaceName := config.GetGlobalKeyspaceName()
+	keyspaceName := keyspace.GetKeyspaceNameBySettings()
 
 	resourcemanager.InstanceResourceManager.Start()
 	storage, dom := createStoreAndDomain(keyspaceName)