tools: pdctl support query region direct

server/api/region.go

@@ -77,6 +77,11 @@ func (h *regionHandler) GetRegionByID(w http.ResponseWriter, r *http.Request) {
 	}
 
 	regionInfo := rc.GetRegion(regionID)
+	failpoint.Inject("RejectGetRegionByIDWhenAccessLeader", func() {
+		if h.svr.GetMember().IsServing() {
+			regionInfo = nil
+		}
+	})
 	if regionInfo == nil {
 		h.rd.JSON(w, http.StatusNotFound, errs.ErrRegionNotFound.FastGenByArgs(regionID).Error())
 		return

tools/pd-ctl/pdctl/command/global.go

@@ -166,10 +166,11 @@ func doRequest(cmd *cobra.Command, prefix string, method string, customHeader ht
 		o(b)
 	}
 	var resp string
+	header := buildNoProxyHeader(cmd, customHeader)
 
 	endpoints := getEndpoints(cmd)
 	err := tryURLs(cmd, endpoints, func(endpoint string) error {
-		return do(endpoint, prefix, method, &resp, customHeader, b)
+		return do(endpoint, prefix, method, &resp, header, b)
 	})
 	return resp, err
 }
@@ -181,13 +182,26 @@ func doRequestSingleEndpoint(cmd *cobra.Command, endpoint, prefix, method string
 		o(b)
 	}
 	var resp string
+	header := buildNoProxyHeader(cmd, customHeader)
 
 	err := requestURL(cmd, endpoint, func(endpoint string) error {
-		return do(endpoint, prefix, method, &resp, customHeader, b)
+		return do(endpoint, prefix, method, &resp, header, b)
 	})
 	return resp, err
 }
 
+func buildNoProxyHeader(cmd *cobra.Command, customHeader http.Header) http.Header {
+	header := customHeader.Clone()
+	if header == nil {
+		header = http.Header{}
+	}
+
+	if direct, err := cmd.Flags().GetBool("no-forward"); err == nil && direct {
+		header.Set(apiutil.PDAllowFollowerHandleHeader, "true")
+	}
+	return header
+}
+
 func dial(req *http.Request) (string, error) {
 	resp, err := dialClient.Do(req)
 	if err != nil {

tools/pd-ctl/pdctl/command/region_command.go

@@ -144,6 +144,7 @@ func NewRegionCommand() *cobra.Command {
 	r.AddCommand(scanRegion)
 
 	r.Flags().String("jq", "", "jq query")
+	r.PersistentFlags().Bool("no-forward", false, "direct request to the endpoint instead of forwarding by PD leader if the flag exists")
 
 	return r
 }

tools/pd-ctl/tests/global_test.go

@@ -19,6 +19,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"sync"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -85,3 +86,57 @@ func TestSendAndGetComponent(t *testing.T) {
 	re.NoError(err)
 	re.Equal(fmt.Sprintf("%s\n", command.PDControlCallerID), string(output))
 }
+
+func TestRegionNoProxyHeader(t *testing.T) {
+	re := require.New(t)
+	var (
+		mu    sync.Mutex
+		count = 0
+	)
+	handler := func(context.Context, *server.Server) (http.Handler, apiutil.APIServiceGroup, error) {
+		mux := http.NewServeMux()
+		mux.HandleFunc("/pd/api/v1/regions", func(w http.ResponseWriter, r *http.Request) {
+			mu.Lock()
+			if vals := r.Header.Values(apiutil.PDAllowFollowerHandleHeader); len(vals) > 0 {
+				count++
+			}
+			mu.Unlock()
+			fmt.Fprint(w, `{}`)
+		})
+		info := apiutil.APIServiceGroup{IsCore: true}
+		return mux, info, nil
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	cluster, err := tests.NewTestClusterWithHandlers(ctx, 1, []server.HandlerBuilder{handler})
+	re.NoError(err)
+	defer cluster.Destroy()
+
+	err = cluster.RunInitialServers()
+	re.NoError(err)
+
+	leaderName := cluster.WaitLeader()
+	re.NotEmpty(leaderName)
+	pdAddr := cluster.GetLeaderServer().GetAddr()
+
+	cmd := cmd.GetRootCmd()
+	_, err = ExecuteCommand(cmd, "-u", pdAddr, "region")
+	re.NoError(err)
+	re.Equal(0, count)
+
+	// PD-Allow-follower-handle is only added when --no-forward=true.
+	_, err = ExecuteCommand(cmd, "-u", pdAddr, "region", "--no-forward")
+	re.NoError(err)
+	re.Equal(1, count)
+
+	// --no-forward=false should not add PD-Allow-follower-handle.
+	_, err = ExecuteCommand(cmd, "-u", pdAddr, "region", "--no-forward=false")
+	re.NoError(err)
+	re.Equal(1, count)
+
+	_, err = ExecuteCommand(cmd, "-u", pdAddr, "region", "--no-forward=true")
+	re.NoError(err)
+	re.Equal(2, count)
+}

tools/pd-ctl/tests/region/region_test.go

@@ -19,6 +19,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"strconv"
+	"strings"
 	"testing"
 	"time"
 
@@ -47,6 +48,10 @@ func TestRegionTestSuite(t *testing.T) {
 
 func (suite *regionTestSuite) SetupSuite() {
 	suite.env = pdTests.NewSchedulingTestEnvironment(suite.T())
+	suite.env.PDCount = 3
+	suite.env.RunFunc(func(cluster *pdTests.TestCluster) {
+		suite.NotEmpty(cluster.WaitLeader())
+	})
 }
 
 func (suite *regionTestSuite) TearDownSuite() {
@@ -64,6 +69,7 @@ func (suite *regionTestSuite) TestRegionKeyFormat() {
 func (suite *regionTestSuite) checkRegionKeyFormat(cluster *pdTests.TestCluster) {
 	re := suite.Require()
 	url := cluster.GetConfig().GetClientURL()
+	cluster.WaitLeader()
 	store := &metapb.Store{
 		Id:    1,
 		State: metapb.StoreState_Up,
@@ -497,3 +503,65 @@ func (suite *regionTestSuite) checkPatrolWithLimit(cluster *pdTests.TestCluster)
 		re.Empty(res["results"])
 	}
 }
+
+func (suite *regionTestSuite) TestFollowerDirect() {
+	suite.env.RunTestInNonMicroserviceEnv(suite.followerDirect)
+}
+
+func (suite *regionTestSuite) followerDirect(cluster *pdTests.TestCluster) {
+	re := suite.Require()
+	re.NotEmpty(cluster.WaitLeader())
+	if err := cluster.GetLeaderServer().BootstrapCluster(); err != nil {
+		re.Contains(err.Error(), "already bootstrapped")
+	}
+	cmd := ctl.GetRootCmd()
+	stores := []*metapb.Store{
+		{
+			Id:    1,
+			State: metapb.StoreState_Up,
+		},
+		{
+			Id:    2,
+			State: metapb.StoreState_Up,
+		},
+		{
+			Id:    3,
+			State: metapb.StoreState_Up,
+		},
+	}
+
+	for i := range stores {
+		pdTests.MustPutStore(re, cluster, stores[i])
+	}
+	metaRegion := &metapb.Region{
+		Id:       100,
+		StartKey: []byte(""),
+		EndKey:   []byte(""),
+		Peers: []*metapb.Peer{
+			{Id: 1, StoreId: 1},
+			{Id: 5, StoreId: 2},
+			{Id: 6, StoreId: 3}},
+		RegionEpoch: &metapb.RegionEpoch{ConfVer: 1, Version: 1},
+	}
+	region := core.NewRegionInfo(metaRegion, metaRegion.Peers[0])
+	re.NoError(cluster.HandleRegionHeartbeat(region))
+	pdAddr := cluster.GetLeaderServer().GetAddr()
+	re.NoError(failpoint.Enable("github.com/tikv/pd/server/api/RejectGetRegionByIDWhenAccessLeader", "return(true)"))
+	defer func() {
+		re.NoError(failpoint.Disable("github.com/tikv/pd/server/api/RejectGetRegionByIDWhenAccessLeader"))
+	}()
+	for _, server := range cluster.GetServers() {
+		serverAddr := server.GetAddr()
+		// leader reject any region info request with --no-forward, followers should work normally.
+		if serverAddr == pdAddr {
+			output, err := tests.ExecuteCommand(cmd, "-u", serverAddr, "region", "100", "--no-forward")
+			re.NoError(err)
+			re.Contains(string(output), "Failed to get region")
+		} else {
+			output, err := tests.ExecuteCommand(cmd, "-u", serverAddr, "region", "100", "--no-forward")
+			re.NoError(err)
+			outputStr := string(output)
+			re.True(strings.Contains(outputStr, "\"id\":100") || strings.Contains(outputStr, "TiKV cluster not bootstrapped"), outputStr)
+		}
+	}
+}