*: enable errcheck (#8277)

ref #1919

Co-authored-by: ti-chi-bot[bot] <108142056+ti-chi-bot[bot]@users.noreply.github.com>

.golangci.yml

@@ -14,7 +14,6 @@ linters:
     - testifylint
     - gofmt
     - revive
-  disable:
     - errcheck
 linters-settings:
   gocritic:
@@ -199,3 +198,15 @@ linters-settings:
         severity: warning
         disabled: false
         exclude: [""]
+issues:
+  exclude-rules:
+    - path: (_test\.go|pkg/mock/.*\.go|tests/.*\.go)
+      linters:
+        - errcheck
+    # following path will enable in the future
+    - path: (pd-analysis|pd-api-bench|pd-backup|pd-ctl|pd-heartbeat-bench|pd-recover|pd-simulator|pd-tso-bench|pd-ut|regions-dump|stores-dump)
+      linters:
+        - errcheck
+    - path: (pkg/schedule/labeler/labeler.go|pkg/mcs/tso/server/config.go|pkg/tso/admin.go|pkg/mcs/tso/server/grpc_service.go|pkg/schedule/schedulers/split_bucket.go|server/api/plugin_disable.go|server/api/plugin_disable.go|server/api/operator.go|server/api/region.go|pkg/schedule/schedulers/balance_leader.go|pkg/mcs/resourcemanager/server/server.go|pkg/mcs/scheduling/server/grpc_service.go|pkg/mcs/resourcemanager/server/.*\.go|plugin/scheduler_example/evict_leader.go|server/api/.*\.go|pkg/replication/replication_mode.go|pkg/mcs/scheduling/server/server.go|pkg/storage/endpoint/gc_safe_point.go|server/.*\.go|pkg/schedule/schedulers/.*\.go|pkg/schedule/placement/rule.go|pkg/mcs/utils/util.go|pkg/keyspace/tso_keyspace_group.go|pkg/tso/allocator_manager.go|pkg/core/store_stats.go|pkg/autoscaling/handler.go|pkg/core/store_stats.go|pkg/keyspace/keyspace.go|pkg/storage/hot_region_storage.go|pkg/syncer/server.go)
+      linters:
+        - errcheck

client/http/types.go

@@ -366,7 +366,7 @@ func (r *Rule) String() string {
 // Clone returns a copy of Rule.
 func (r *Rule) Clone() *Rule {
 	var clone Rule
-	json.Unmarshal([]byte(r.String()), &clone)
+	_ = json.Unmarshal([]byte(r.String()), &clone)
 	clone.StartKey = append(r.StartKey[:0:0], r.StartKey...)
 	clone.EndKey = append(r.EndKey[:0:0], r.EndKey...)
 	return &clone

client/pd_service_discovery.go

@@ -805,7 +805,9 @@ func (c *pdServiceDiscovery) SetTSOLocalServURLsUpdatedCallback(callback tsoLoca
 func (c *pdServiceDiscovery) SetTSOGlobalServURLUpdatedCallback(callback tsoGlobalServURLUpdatedFunc) {
 	url := c.getLeaderURL()
 	if len(url) > 0 {
-		callback(url)
+		if err := callback(url); err != nil {
+			log.Error("[tso] failed to call back when tso global service url update", zap.String("url", url), errs.ZapError(err))
+		}
 	}
 	c.tsoGlobalAllocLeaderUpdatedCb = callback
 }

client/resource_manager_client.go

@@ -319,7 +319,9 @@ func (c *client) handleResourceTokenDispatcher(dispatcherCtx context.Context, tb
 		// If the stream is nil or the leader has changed, try to reconnect.
 		if toReconnect {
 			connection.reset()
-			c.tryResourceManagerConnect(dispatcherCtx, &connection)
+			if err := c.tryResourceManagerConnect(dispatcherCtx, &connection); err != nil {
+				log.Error("[resource_manager] try to connect token leader failed", errs.ZapError(err))
+			}
 			log.Info("[resource_manager] token leader may change, try to reconnect the stream")
 			stream, streamCtx = connection.stream, connection.ctx
 		}

client/tso_client.go

@@ -118,7 +118,9 @@ func (c *tsoClient) getOption() *option { return c.option }
 func (c *tsoClient) getServiceDiscovery() ServiceDiscovery { return c.svcDiscovery }
 
 func (c *tsoClient) setup() {
-	c.svcDiscovery.CheckMemberChanged()
+	if err := c.svcDiscovery.CheckMemberChanged(); err != nil {
+		log.Warn("[tso] failed to check member changed", errs.ZapError(err))
+	}
 	c.updateTSODispatcher()
 
 	// Start the daemons.

client/tso_service_discovery.go

@@ -339,7 +339,9 @@ func (c *tsoServiceDiscovery) ScheduleCheckMemberChanged() {
 // CheckMemberChanged Immediately check if there is any membership change among the primary/secondaries in
 // a primary/secondary configured cluster.
 func (c *tsoServiceDiscovery) CheckMemberChanged() error {
-	c.apiSvcDiscovery.CheckMemberChanged()
+	if err := c.apiSvcDiscovery.CheckMemberChanged(); err != nil {
+		log.Warn("[tso] failed to check member changed", errs.ZapError(err))
+	}
 	if err := c.retry(tsoQueryRetryMaxTimes, tsoQueryRetryInterval, c.updateMember); err != nil {
 		log.Error("[tso] failed to update member", errs.ZapError(err))
 		return err
@@ -366,7 +368,9 @@ func (c *tsoServiceDiscovery) SetTSOLocalServURLsUpdatedCallback(callback tsoLoc
 func (c *tsoServiceDiscovery) SetTSOGlobalServURLUpdatedCallback(callback tsoGlobalServURLUpdatedFunc) {
 	url := c.getPrimaryURL()
 	if len(url) > 0 {
-		callback(url)
+		if err := callback(url); err != nil {
+			log.Error("[tso] failed to call back when tso global service url update", zap.String("url", url), errs.ZapError(err))
+		}
 	}
 	c.globalAllocPrimariesUpdatedCb = callback
 }

pkg/core/region.go

@@ -746,7 +746,7 @@ func GenerateRegionGuideFunc(enableLog bool) RegionGuideFunc {
 		regionID := region.GetID()
 		if logRunner != nil {
 			debug = func(msg string, fields ...zap.Field) {
-				logRunner.RunTask(
+				_ = logRunner.RunTask(
 					regionID,
 					"DebugLog",
 					func() {
@@ -755,7 +755,7 @@ func GenerateRegionGuideFunc(enableLog bool) RegionGuideFunc {
 				)
 			}
 			info = func(msg string, fields ...zap.Field) {
-				logRunner.RunTask(
+				_ = logRunner.RunTask(
 					regionID,
 					"InfoLog",
 					func() {

pkg/election/leadership.go

@@ -161,7 +161,7 @@ func (ls *Leadership) Campaign(leaseTimeout int64, leaderData string, cmps ...cl
 
 	failpoint.Inject("skipGrantLeader", func(val failpoint.Value) {
 		var member pdpb.Member
-		member.Unmarshal([]byte(leaderData))
+		_ = member.Unmarshal([]byte(leaderData))
 		name, ok := val.(string)
 		if ok && member.Name == name {
 			failpoint.Return(errors.Errorf("failed to grant lease"))

pkg/election/lease.go

@@ -84,7 +84,9 @@ func (l *lease) Close() error {
 	if l.ID.Load() != nil {
 		leaseID = l.ID.Load().(clientv3.LeaseID)
 	}
-	l.lease.Revoke(ctx, leaseID)
+	if _, err := l.lease.Revoke(ctx, leaseID); err != nil {
+		log.Error("revoke lease failed", zap.String("purpose", l.Purpose), errs.ZapError(err))
+	}
 	return l.lease.Close()
 }
 

pkg/mcs/scheduling/server/cluster.go

@@ -624,7 +624,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 		// Due to some config changes need to update the region stats as well,
 		// so we do some extra checks here.
 		if hasRegionStats && c.regionStats.RegionStatsNeedUpdate(region) {
-			ctx.TaskRunner.RunTask(
+			_ = ctx.TaskRunner.RunTask(
 				regionID,
 				ratelimit.ObserveRegionStatsAsync,
 				func() {
@@ -636,7 +636,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 		}
 		// region is not updated to the subtree.
 		if origin.GetRef() < 2 {
-			ctx.TaskRunner.RunTask(
+			_ = ctx.TaskRunner.RunTask(
 				regionID,
 				ratelimit.UpdateSubTree,
 				func() {
@@ -660,7 +660,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 			tracer.OnSaveCacheFinished()
 			return err
 		}
-		ctx.TaskRunner.RunTask(
+		_ = ctx.TaskRunner.RunTask(
 			regionID,
 			ratelimit.UpdateSubTree,
 			func() {
@@ -669,7 +669,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 			ratelimit.WithRetained(retained),
 		)
 		tracer.OnUpdateSubTreeFinished()
-		ctx.TaskRunner.RunTask(
+		_ = ctx.TaskRunner.RunTask(
 			regionID,
 			ratelimit.HandleOverlaps,
 			func() {
@@ -679,7 +679,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 	}
 	tracer.OnSaveCacheFinished()
 	// handle region stats
-	ctx.TaskRunner.RunTask(
+	_ = ctx.TaskRunner.RunTask(
 		regionID,
 		ratelimit.CollectRegionStatsAsync,
 		func() {

pkg/mcs/utils/util.go

@@ -266,15 +266,19 @@ func StopHTTPServer(s server) {
 	ch := make(chan struct{})
 	go func() {
 		defer close(ch)
-		s.GetHTTPServer().Shutdown(ctx)
+		if err := s.GetHTTPServer().Shutdown(ctx); err != nil {
+			log.Error("http server graceful shutdown failed", errs.ZapError(err))
+		}
 	}()
 
 	select {
 	case <-ch:
 	case <-ctx.Done():
 		// Took too long, manually close open transports
 		log.Warn("http server graceful shutdown timeout, forcing close")
-		s.GetHTTPServer().Close()
+		if err := s.GetHTTPServer().Close(); err != nil {
+			log.Warn("http server close failed", errs.ZapError(err))
+		}
 		// concurrent Graceful Shutdown should be interrupted
 		<-ch
 	}

pkg/schedule/scatter/region_scatterer.go

@@ -255,7 +255,7 @@ func (r *RegionScatterer) scatterRegions(regions map[uint64]*core.RegionInfo, fa
 					continue
 				}
 				failpoint.Inject("scatterHbStreamsDrain", func() {
-					r.opController.GetHBStreams().Drain(1)
+					_ = r.opController.GetHBStreams().Drain(1)
 					r.opController.RemoveOperator(op, operator.AdminStop)
 				})
 			}

pkg/utils/apiutil/apiutil.go

@@ -116,14 +116,14 @@ func TagJSONError(err error) error {
 func ErrorResp(rd *render.Render, w http.ResponseWriter, err error) {
 	if err == nil {
 		log.Error("nil is given to errorResp")
-		rd.JSON(w, http.StatusInternalServerError, "nil error")
+		_ = rd.JSON(w, http.StatusInternalServerError, "nil error")
 		return
 	}
 	if errCode := errcode.CodeChain(err); errCode != nil {
 		w.Header().Set("TiDB-Error-Code", errCode.Code().CodeStr().String())
-		rd.JSON(w, errCode.Code().HTTPCode(), errcode.NewJSONFormat(errCode))
+		_ = rd.JSON(w, errCode.Code().HTTPCode(), errcode.NewJSONFormat(errCode))
 	} else {
-		rd.JSON(w, http.StatusInternalServerError, err.Error())
+		_ = rd.JSON(w, http.StatusInternalServerError, err.Error())
 	}
 }
 

pkg/utils/typeutil/clone.go

@@ -36,6 +36,6 @@ func DeepClone[T Codec](src T, factory func() T) T {
 		return dst
 	}
 	dst := factory()
-	dst.Unmarshal(b)
+	_ = dst.Unmarshal(b)
 	return dst
 }

server/cluster/cluster.go

@@ -1058,7 +1058,7 @@ func (c *RaftCluster) processRegionHeartbeat(ctx *core.MetaProcessContext, regio
 		// region stats needs to be collected in API mode.
 		// We need to think of a better way to reduce this part of the cost in the future.
 		if hasRegionStats && c.regionStats.RegionStatsNeedUpdate(region) {
-			ctx.MiscRunner.RunTask(
+			_ = ctx.MiscRunner.RunTask(
 				regionID,
 				ratelimit.ObserveRegionStatsAsync,
 				func() {
@@ -1070,7 +1070,7 @@ func (c *RaftCluster) processRegionHeartbeat(ctx *core.MetaProcessContext, regio
 		}
 		// region is not updated to the subtree.
 		if origin.GetRef() < 2 {
-			ctx.TaskRunner.RunTask(
+			_ = ctx.TaskRunner.RunTask(
 				regionID,
 				ratelimit.UpdateSubTree,
 				func() {
@@ -1098,7 +1098,7 @@ func (c *RaftCluster) processRegionHeartbeat(ctx *core.MetaProcessContext, regio
 			tracer.OnSaveCacheFinished()
 			return err
 		}
-		ctx.TaskRunner.RunTask(
+		_ = ctx.TaskRunner.RunTask(
 			regionID,
 			ratelimit.UpdateSubTree,
 			func() {
@@ -1109,7 +1109,7 @@ func (c *RaftCluster) processRegionHeartbeat(ctx *core.MetaProcessContext, regio
 		tracer.OnUpdateSubTreeFinished()
 
 		if !c.IsServiceIndependent(mcsutils.SchedulingServiceName) {
-			ctx.MiscRunner.RunTask(
+			_ = ctx.MiscRunner.RunTask(
 				regionID,
 				ratelimit.HandleOverlaps,
 				func() {
@@ -1122,7 +1122,7 @@ func (c *RaftCluster) processRegionHeartbeat(ctx *core.MetaProcessContext, regio
 
 	tracer.OnSaveCacheFinished()
 	// handle region stats
-	ctx.MiscRunner.RunTask(
+	_ = ctx.MiscRunner.RunTask(
 		regionID,
 		ratelimit.CollectRegionStatsAsync,
 		func() {
@@ -1136,7 +1136,7 @@ func (c *RaftCluster) processRegionHeartbeat(ctx *core.MetaProcessContext, regio
 	tracer.OnCollectRegionStatsFinished()
 	if c.storage != nil {
 		if saveKV {
-			ctx.MiscRunner.RunTask(
+			_ = ctx.MiscRunner.RunTask(
 				regionID,
 				ratelimit.SaveRegionToKV,
 				func() {