mcs: support scheduler config forward and enable some tests

pkg/mcs/scheduling/server/apis/v1/api.go

@@ -26,6 +26,7 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/joho/godotenv"
 	"github.com/pingcap/log"
+	"github.com/tikv/pd/pkg/errs"
 	scheserver "github.com/tikv/pd/pkg/mcs/scheduling/server"
 	mcsutils "github.com/tikv/pd/pkg/mcs/utils"
 	sche "github.com/tikv/pd/pkg/schedule/core"
@@ -128,6 +129,7 @@ func (s *Service) RegisterSchedulersRouter() {
 	router := s.root.Group("schedulers")
 	router.GET("", getSchedulers)
 	router.GET("/diagnostic/:name", getDiagnosticResult)
+	router.GET("/config/:name/:suffix", getSchedulerConfigByName)
 	// TODO: in the future, we should split pauseOrResumeScheduler to two different APIs.
 	// And we need to do one-to-two forwarding in the API middleware.
 	router.POST("/:name", pauseOrResumeScheduler)
@@ -385,6 +387,38 @@ func getSchedulers(c *gin.Context) {
 	c.IndentedJSON(http.StatusOK, output)
 }
 
+func getSchedulerConfigByName(c *gin.Context) {
+	svr := c.MustGet(multiservicesapi.ServiceContextKey).(*scheserver.Server)
+	handlers := svr.GetCoordinator().GetSchedulersController().GetSchedulerHandlers()
+	name := c.Param("name")
+	if _, ok := handlers[name]; !ok {
+		c.String(http.StatusNotFound, errs.ErrSchedulerNotFound.GenWithStackByArgs().Error())
+		return
+	}
+	co := svr.GetCoordinator()
+	if co == nil {
+		c.String(http.StatusInternalServerError, errs.ErrNotBootstrapped.GenWithStackByArgs().Error())
+		return
+	}
+	sc := co.GetSchedulersController()
+	if sc == nil {
+		c.String(http.StatusInternalServerError, errs.ErrNotBootstrapped.GenWithStackByArgs().Error())
+		return
+	}
+	isDisabled, err := sc.IsSchedulerDisabled(name)
+	if err != nil {
+		c.String(http.StatusInternalServerError, err.Error())
+		return
+	}
+	if isDisabled {
+		c.String(http.StatusNotFound, errs.ErrSchedulerNotFound.GenWithStackByArgs().Error())
+		return
+	}
+	suffix := c.Param("suffix")
+	c.Request.URL.Path = "/" + suffix
+	handlers[name].ServeHTTP(c.Writer, c.Request)
+}
+
 // @Tags     schedulers
 // @Summary  List schedulers diagnostic result.
 // @Produce  json

pkg/schedule/handler/handler.go

@@ -837,7 +837,20 @@ func (h *Handler) GetSchedulerByStatus(status string, needTS bool) (interface{},
 		}
 		return disabledSchedulers, nil
 	default:
-		return schedulers, nil
+		// The default scheduler could not be deleted in scheduling server,
+		// so schedulers could only be disabled.
+		// We should not return the disabled schedulers here.
+		var enabledSchedulers []string
+		for _, scheduler := range schedulers {
+			disabled, err := sc.IsSchedulerDisabled(scheduler)
+			if err != nil {
+				return nil, err
+			}
+			if !disabled {
+				enabledSchedulers = append(enabledSchedulers, scheduler)
+			}
+		}
+		return enabledSchedulers, nil
 	}
 }
 

pkg/utils/testutil/api_check.go

@@ -37,29 +37,29 @@ func StatusOK(re *require.Assertions) func([]byte, int, http.Header) {
 
 // StatusNotOK is used to check whether http response code is not equal http.StatusOK.
 func StatusNotOK(re *require.Assertions) func([]byte, int, http.Header) {
-	return func(_ []byte, i int, _ http.Header) {
-		re.NotEqual(http.StatusOK, i)
+	return func(resp []byte, i int, _ http.Header) {
+		re.NotEqual(http.StatusOK, i, "resp: "+string(resp))
 	}
 }
 
 // ExtractJSON is used to check whether given data can be extracted successfully.
 func ExtractJSON(re *require.Assertions, data interface{}) func([]byte, int, http.Header) {
-	return func(res []byte, _ int, _ http.Header) {
-		re.NoError(json.Unmarshal(res, data))
+	return func(resp []byte, _ int, _ http.Header) {
+		re.NoError(json.Unmarshal(resp, data), "resp: "+string(resp))
 	}
 }
 
 // StringContain is used to check whether response context contains given string.
 func StringContain(re *require.Assertions, sub string) func([]byte, int, http.Header) {
-	return func(res []byte, _ int, _ http.Header) {
-		re.Contains(string(res), sub)
+	return func(resp []byte, _ int, _ http.Header) {
+		re.Contains(string(resp), sub, "resp: "+string(resp))
 	}
 }
 
 // StringEqual is used to check whether response context equal given string.
 func StringEqual(re *require.Assertions, str string) func([]byte, int, http.Header) {
-	return func(res []byte, _ int, _ http.Header) {
-		re.Contains(string(res), str)
+	return func(resp []byte, _ int, _ http.Header) {
+		re.Contains(string(resp), str, "resp: "+string(resp))
 	}
 }
 

server/api/server.go

@@ -52,6 +52,7 @@ func NewHandler(_ context.Context, svr *server.Server) (http.Handler, apiutil.AP
 	//	"/schedulers", http.MethodGet
 	//	"/schedulers/{name}", http.MethodPost
 	//	"/schedulers/diagnostic/{name}", http.MethodGet
+	//	"/scheduler-config", http.MethodGet
 	//	"/hotspot/regions/read", http.MethodGet
 	//	"/hotspot/regions/write", http.MethodGet
 	//	"/hotspot/regions/history", http.MethodGet
@@ -90,6 +91,11 @@ func NewHandler(_ context.Context, svr *server.Server) (http.Handler, apiutil.AP
 				scheapi.APIPathPrefix+"/schedulers",
 				mcs.SchedulingServiceName,
 				[]string{http.MethodGet}),
+			serverapi.MicroserviceRedirectRule(
+				prefix+"/scheduler-config",
+				scheapi.APIPathPrefix+"/schedulers/config",
+				mcs.SchedulingServiceName,
+				[]string{http.MethodGet}),
 			serverapi.MicroserviceRedirectRule(
 				prefix+"/schedulers/", // Note: this means "/schedulers/{name}"
 				scheapi.APIPathPrefix+"/schedulers",

server/config/persist_options.go

@@ -789,11 +789,10 @@ func (o *PersistOptions) Persist(storage endpoint.ConfigStorage) error {
 		},
 		StoreConfig: *o.GetStoreConfig(),
 	}
-	err := storage.SaveConfig(cfg)
 	failpoint.Inject("persistFail", func() {
-		err = errors.New("fail to persist")
+		failpoint.Return(errors.New("fail to persist"))
 	})
-	return err
+	return storage.SaveConfig(cfg)
 }
 
 // Reload reloads the configuration from the storage.

tests/integrations/mcs/scheduling/api_test.go

@@ -170,6 +170,7 @@ func (suite *apiTestSuite) TestAPIForward() {
 	//	"/schedulers", http.MethodGet
 	//	"/schedulers/{name}", http.MethodPost
 	//	"/schedulers/diagnostic/{name}", http.MethodGet
+	// 	"/scheduler-config/", http.MethodGet
 	// Should not redirect:
 	//	"/schedulers", http.MethodPost
 	//	"/schedulers/{name}", http.MethodDelete
@@ -189,6 +190,17 @@ func (suite *apiTestSuite) TestAPIForward() {
 		testutil.WithHeader(re, apiutil.ForwardToMicroServiceHeader, "true"))
 	suite.NoError(err)
 
+	schedulers := []string{
+		"balance-leader-scheduler",
+		"balance-witness-scheduler",
+		"balance-hot-region-scheduler",
+	}
+	for _, schedulerName := range schedulers {
+		err = testutil.ReadGetJSON(re, testDialClient, fmt.Sprintf("%s/%s/%s/%s", urlPrefix, "scheduler-config", schedulerName, "list"), &resp,
+			testutil.WithHeader(re, apiutil.ForwardToMicroServiceHeader, "true"))
+		suite.NoError(err)
+	}
+
 	err = testutil.CheckPostJSON(testDialClient, fmt.Sprintf("%s/%s", urlPrefix, "schedulers"), pauseArgs,
 		testutil.WithoutHeader(re, apiutil.ForwardToMicroServiceHeader))
 	re.NoError(err)