Make evict leader scheduler compatitable (#1831) (#1841)

* fix evict leader

* Update tikv_creater.go

* fix lint

* Update pkg/webhook/pod/tikv_creater.go

Co-Authored-By: DanielZhangQD <36026334+DanielZhangQD@users.noreply.github.com>

* revise by comment

Co-authored-by: Song Gao <disxiaofei@163.com>
Co-authored-by: DanielZhangQD <36026334+DanielZhangQD@users.noreply.github.com>

manifests/crd.yaml

@@ -1611,6 +1611,9 @@ spec:
                             after cluster creation Optional: Defaults to 64'
                           format: int64
                           type: integer
+                        schedulers-payload:
+                          description: Only used to display
+                          type: object
                         schedulers-v2:
                           description: Schedulers support for loding customized schedulers
                             Immutable, change should be made through pd-ctl after

pkg/apis/pingcap/v1alpha1/pd_config.go

@@ -337,6 +337,10 @@ type PDScheduleConfig struct {
 	// Immutable, change should be made through pd-ctl after cluster creation
 	// +optional
 	Schedulers *PDSchedulerConfigs `toml:"schedulers,omitempty" json:"schedulers-v2,omitempty"` // json v2 is for the sake of compatible upgrade
+
+	// Only used to display
+	// +optional
+	SchedulersPayload map[string]string `toml:"schedulers-payload" json:"schedulers-payload,omitempty"`
 }
 
 type PDSchedulerConfigs []PDSchedulerConfig

pkg/manager/member/pd_upgrader.go

@@ -74,6 +74,7 @@ func (pu *pdUpgrader) gracefulUpgrade(tc *v1alpha1.TidbCluster, oldSet *apps.Sta
 
 	if controller.PodWebhookEnabled {
 		setUpgradePartition(newSet, 0)
+		return nil
 	}
 
 	setUpgradePartition(newSet, *oldSet.Spec.UpdateStrategy.RollingUpdate.Partition)

pkg/manager/member/tikv_upgrader.go

@@ -89,6 +89,7 @@ func (tku *tikvUpgrader) Upgrade(tc *v1alpha1.TidbCluster, oldSet *apps.Stateful
 
 	if controller.PodWebhookEnabled {
 		setUpgradePartition(newSet, 0)
+		return nil
 	}
 
 	setUpgradePartition(newSet, *oldSet.Spec.UpdateStrategy.RollingUpdate.Partition)

pkg/webhook/pod/tikv_creater.go

@@ -14,23 +14,29 @@
 package pod
 
 import (
+	"encoding/json"
 	"fmt"
 	"strings"
 
-	"k8s.io/apimachinery/pkg/util/sets"
-
 	"github.com/pingcap/tidb-operator/pkg/apis/pingcap/v1alpha1"
 	"github.com/pingcap/tidb-operator/pkg/pdapi"
 	"github.com/pingcap/tidb-operator/pkg/webhook/util"
 	admission "k8s.io/api/admission/v1beta1"
 	core "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/klog"
 )
 
 const (
-	tikvNotBootstrapped = `TiKV cluster not bootstrapped, please start TiKV first"`
+	tikvNotBootstrapped  = `TiKV cluster not bootstrapped, please start TiKV first"`
+	evictSchedulerLeader = "evict-leader-scheduler"
 )
 
+// Payload only used to unmarshal the data from pdapi
+type Payload struct {
+	StoreIdRanges map[string]interface{} `json:"store-id-ranges"`
+}
+
 func (pc *PodAdmissionControl) admitCreateTiKVPod(pod *core.Pod, tc *v1alpha1.TidbCluster, pdClient pdapi.PDClient) *admission.AdmissionResponse {
 
 	name := pod.Name
@@ -61,10 +67,9 @@ func (pc *PodAdmissionControl) admitCreateTiKVPod(pod *core.Pod, tc *v1alpha1.Ti
 		return util.ARSuccess()
 	}
 
-	schedulerIds := sets.String{}
-	for _, s := range evictLeaderSchedulers {
-		id := strings.Split(s, "-")[3]
-		schedulerIds.Insert(id)
+	schedulerIds, err := filterLeaderEvictScheduler(evictLeaderSchedulers, pdClient)
+	if err != nil {
+		return util.ARFail(err)
 	}
 
 	// if the pod which is going to be created already have a store and was in evictLeaderSchedulers,
@@ -84,3 +89,34 @@ func (pc *PodAdmissionControl) admitCreateTiKVPod(pod *core.Pod, tc *v1alpha1.Ti
 
 	return util.ARSuccess()
 }
+
+// This method is to make compatible between old pdapi version and 4.0 pdapi version.
+// To get more detail, see: https://github.com/pingcap/tidb-operator/pull/1831
+func filterLeaderEvictScheduler(evictLeaderSchedulers []string, pdClient pdapi.PDClient) (sets.String, error) {
+	schedulerIds := sets.String{}
+	if len(evictLeaderSchedulers) == 1 && evictLeaderSchedulers[0] == evictSchedulerLeader {
+		c, err := pdClient.GetConfig()
+		if err != nil {
+			return schedulerIds, err
+		}
+		if c.Schedule != nil && c.Schedule.SchedulersPayload != nil {
+			v, ok := c.Schedule.SchedulersPayload[evictSchedulerLeader]
+			if ok {
+				payload := &Payload{}
+				err := json.Unmarshal([]byte(v), payload)
+				if err != nil {
+					return schedulerIds, err
+				}
+				for k := range payload.StoreIdRanges {
+					schedulerIds.Insert(k)
+				}
+			}
+		}
+	} else {
+		for _, s := range evictLeaderSchedulers {
+			id := strings.Split(s, "-")[3]
+			schedulerIds.Insert(id)
+		}
+	}
+	return schedulerIds, nil
+}