style: fix lint warnings - unhandled errors

Some of the warnings were fixed but others were skipped.
We can find skipped warnings by running grep ` //nolint:errcheck // TODO: Handle an error returned.`.

cmd/varlogmr/app/metadata_repository.go

@@ -29,7 +29,9 @@ func Main(opts *metarepos.MetadataRepositoryOptions) error {
 		return err
 	}
 
-	defer logger.Sync()
+	defer func() {
+		_ = logger.Sync()
+	}()
 
 	opts.Logger = logger
 	opts.ReporterClientFac = metarepos.NewReporterClientFactory(

internal/admin/admin.go

@@ -896,7 +896,7 @@ func (adm *Admin) HandleHeartbeatTimeout(ctx context.Context, snid types.Storage
 	for _, ls := range meta.GetLogStreams() {
 		if ls.IsReplica(snid) {
 			adm.logger.Debug("seal due to heartbeat timeout", zap.Any("snid", snid), zap.Any("lsid", ls.LogStreamID))
-			adm.seal(ctx, ls.TopicID, ls.LogStreamID)
+			_, _, _ = adm.seal(ctx, ls.TopicID, ls.LogStreamID)
 		}
 	}
 }
@@ -911,14 +911,14 @@ func (adm *Admin) checkLogStreamStatus(ctx context.Context, tpid types.TopicID,
 	case varlogpb.LogStreamStatusRunning:
 		if mrStatus.Sealed() || replicaStatus.Sealed() {
 			adm.logger.Info("seal due to status mismatch", zap.Any("lsid", lsid))
-			adm.sealInternal(ctx, tpid, lsid)
+			_, _, _ = adm.sealInternal(ctx, tpid, lsid)
 		}
 
 	case varlogpb.LogStreamStatusSealing:
 		for _, r := range lsStat.Replicas() {
 			if r.Status != varlogpb.LogStreamStatusSealed {
 				adm.logger.Info("seal due to status", zap.Any("lsid", lsid))
-				adm.sealInternal(ctx, tpid, lsid)
+				_, _, _ = adm.sealInternal(ctx, tpid, lsid)
 				return
 			}
 		}
@@ -941,7 +941,7 @@ func (adm *Admin) checkLogStreamStatus(ctx context.Context, tpid types.TopicID,
 				return
 			} else if r.Status == varlogpb.LogStreamStatusSealing {
 				adm.logger.Info("seal due to unexpected status", zap.Any("lsid", lsid))
-				adm.sealInternal(ctx, tpid, lsid)
+				_, _, _ = adm.sealInternal(ctx, tpid, lsid)
 				return
 			}
 		}
@@ -1043,7 +1043,7 @@ func (adm *Admin) HandleReport(ctx context.Context, snm *snpb.StorageNodeMetadat
 			continue
 		}
 		if time.Since(ls.CreatedTime) > adm.logStreamGCTimeout {
-			adm.removeLogStreamReplica(ctx, snm.StorageNode.StorageNodeID, ls.TopicID, ls.LogStreamID)
+			_ = adm.removeLogStreamReplica(ctx, snm.StorageNode.StorageNodeID, ls.TopicID, ls.LogStreamID)
 		}
 	}
 

internal/admin/snmanager/manager.go

@@ -85,7 +85,7 @@ func New(ctx context.Context, opts ...Option) (StorageNodeManager, error) {
 		clients: clients,
 	}
 
-	sm.refresh(ctx)
+	sm.refresh(ctx) //nolint:errcheck,revive // TODO: Handle an error returned.
 	return sm, nil
 }
 
@@ -104,7 +104,7 @@ func (sm *snManager) refresh(ctx context.Context) error {
 			defer wg.Done()
 			ctx, cancel := context.WithCancel(ctx)
 			defer cancel()
-			sm.clients.GetOrConnect(ctx, snd.StorageNodeID, snd.Address)
+			sm.clients.GetOrConnect(ctx, snd.StorageNodeID, snd.Address) //nolint:errcheck,revive // TODO:: Handle an error returned.
 		}()
 	}
 	wg.Wait()
@@ -181,7 +181,7 @@ func (sm *snManager) AddLogStreamReplica(ctx context.Context, snid types.Storage
 func (sm *snManager) addLogStreamReplica(ctx context.Context, snid types.StorageNodeID, tpid types.TopicID, lsid types.LogStreamID, path string) error {
 	mc, err := sm.clients.Get(snid)
 	if err != nil {
-		sm.refresh(ctx)
+		sm.refresh(ctx) //nolint:errcheck,revive // TODO: Handle an error returned.
 		return errors.Wrap(verrors.ErrNotExist, "storage node")
 	}
 	return mc.AddLogStreamReplica(ctx, tpid, lsid, path)
@@ -203,7 +203,7 @@ func (sm *snManager) AddLogStream(ctx context.Context, lsd *varlogpb.LogStreamDe
 func (sm *snManager) RemoveLogStreamReplica(ctx context.Context, snid types.StorageNodeID, tpid types.TopicID, lsid types.LogStreamID) error {
 	mc, err := sm.clients.Get(snid)
 	if err != nil {
-		sm.refresh(ctx)
+		sm.refresh(ctx) //nolint:errcheck,revive // TODO: Handle an error returned.
 		return errors.Wrap(verrors.ErrNotExist, "storage node")
 	}
 	return mc.RemoveLogStream(ctx, tpid, lsid)
@@ -221,7 +221,7 @@ func (sm *snManager) Seal(ctx context.Context, tpid types.TopicID, lsid types.Lo
 		storageNodeID := replica.GetStorageNodeID()
 		cli, err := sm.clients.Get(storageNodeID)
 		if err != nil {
-			sm.refresh(ctx)
+			sm.refresh(ctx) //nolint:errcheck,revive // TODO: Handle an error returned.
 			return nil, errors.Wrap(verrors.ErrNotExist, "storage node")
 		}
 		status, highWatermark, errSeal := cli.Seal(ctx, tpid, lsid, lastCommittedGLSN)
@@ -272,18 +272,18 @@ func (sm *snManager) Sync(ctx context.Context, tpid types.TopicID, lsid types.Lo
 	}
 
 	if !storageNodeIDs.Contains(srcID) || !storageNodeIDs.Contains(dstID) {
-		sm.refresh(ctx)
+		sm.refresh(ctx) //nolint:errcheck,revive // TODO:: Handle an error returned.
 		return nil, errors.Wrap(verrors.ErrNotExist, "storage node")
 	}
 
 	srcCli, err := sm.clients.Get(srcID)
 	if err != nil {
-		sm.refresh(ctx)
+		sm.refresh(ctx) //nolint:errcheck,revive // TODO:: Handle an error returned.
 		return nil, errors.Wrap(verrors.ErrNotExist, "storage node")
 	}
 	dstCli, err := sm.clients.Get(dstID)
 	if err != nil {
-		sm.refresh(ctx)
+		sm.refresh(ctx) //nolint:errcheck,revive // TODO:: Handle an error returned.
 		return nil, errors.Wrap(verrors.ErrNotExist, "storage node")
 	}
 
@@ -321,7 +321,7 @@ func (sm *snManager) Unseal(ctx context.Context, tpid types.TopicID, lsid types.
 		storageNodeID := replica.GetStorageNodeID()
 		cli, err := sm.clients.Get(storageNodeID)
 		if err != nil {
-			sm.refresh(ctx)
+			sm.refresh(ctx) //nolint:errcheck,revive // TODO:: Handle an error returned.
 			return errors.Wrap(verrors.ErrNotExist, "storage node")
 		}
 		if err := cli.Unseal(ctx, tpid, lsid, replicas); err != nil {
@@ -354,7 +354,7 @@ func (sm *snManager) Trim(ctx context.Context, tpid types.TopicID, lastGLSN type
 
 			cli, err := sm.clients.Get(rd.StorageNodeID)
 			if err != nil {
-				sm.refresh(ctx)
+				sm.refresh(ctx) //nolint:errcheck,revive // TODO:: Handle an error returned.
 				return nil, err
 			}
 			clients[rd.StorageNodeID] = cli

internal/metarepos/raft.go

@@ -330,7 +330,7 @@ func (rc *raftNode) openWAL(snapshot *raftpb.Snapshot) *wal.WAL {
 		if err != nil {
 			rc.logger.Panic("create wal error", zap.String("err", err.Error()))
 		}
-		w.Close()
+		w.Close() //nolint:errcheck,revive // TODO:: Handle an error returned.
 	}
 
 	walsnap := walpb.Snapshot{}
@@ -368,15 +368,15 @@ func (rc *raftNode) replayWAL(snapshot *raftpb.Snapshot) *wal.WAL {
 
 	rc.raftStorage = raft.NewMemoryStorage()
 	if snapshot != nil {
-		rc.raftStorage.ApplySnapshot(*snapshot)
+		rc.raftStorage.ApplySnapshot(*snapshot) //nolint:errcheck,revive // TODO:: Handle an error returned.
 		rc.publishSnapshot(*snapshot)
 	}
-	rc.raftStorage.SetHardState(st)
+	rc.raftStorage.SetHardState(st) //nolint:errcheck,revive // TODO:: Handle an error returned.
 
 	//TODO:: WAL replay to state machine
 
 	// append to storage so raft starts at the right place in log
-	rc.raftStorage.Append(ents)
+	rc.raftStorage.Append(ents) //nolint:errcheck,revive // TODO:: Handle an error returned.
 
 	// send nil once lastIndex is published so client knows commit channel is current
 	if len(ents) > 0 {
@@ -461,7 +461,7 @@ func (rc *raftNode) start() {
 		ErrorC:      make(chan error),
 	}
 
-	rc.transport.Start()
+	rc.transport.Start() //nolint:errcheck,revive // TODO:: Handle an error returned.
 
 	for i, peer := range rpeers {
 		if peer.ID == uint64(rc.id) {
@@ -571,7 +571,7 @@ func (rc *raftNode) stop(transfer bool) {
 	rc.runner.Stop()
 
 	if rc.wal != nil {
-		rc.wal.Close()
+		rc.wal.Close() //nolint:errcheck,revive // TODO:: Handle an error returned.
 	}
 
 	close(rc.commitC)
@@ -589,7 +589,7 @@ func (rc *raftNode) stopHTTP() {
 	rc.transport.Stop()
 	rc.httprunner.Stop()
 	// TODO: use context or shutdown timeout
-	rc.httpserver.Shutdown(context.TODO())
+	rc.httpserver.Shutdown(context.TODO()) //nolint:errcheck,revive // TODO: Handle an error returned.
 }
 
 type snapReaderCloser struct{ *bytes.Reader }
@@ -621,7 +621,7 @@ func (rc *raftNode) processMessages(ms []raftpb.Message) []raftpb.Message {
 				)
 
 				//TODO:: concurrency limit
-				rc.runner.Run(func(context.Context) {
+				rc.runner.Run(func(context.Context) { //nolint:errcheck,revive // TODO:: Handle an error returned.
 					rc.transport.SendSnapshot(*sm)
 				})
 
@@ -747,7 +747,7 @@ Loop:
 
 			confChangeCount++
 			cc.ID = confChangeCount
-			rc.node.ProposeConfChange(context.TODO(), cc)
+			rc.node.ProposeConfChange(context.TODO(), cc) //nolint:errcheck,revive // TODO:: Handle an error returned.
 		case <-ctx.Done():
 			break Loop
 		}
@@ -776,17 +776,17 @@ func (rc *raftNode) processRaftEvent(ctx context.Context) {
 			rc.membership.updateState(rd.SoftState)
 			rc.publishLeader(ctx, rd.SoftState)
 
-			rc.saveWal(rd.HardState, rd.Entries)
+			rc.saveWal(rd.HardState, rd.Entries) //nolint:errcheck,revive // TODO: Handle an error returned.
 
 			if !raft.IsEmptySnap(rd.Snapshot) {
-				rc.saveSnap(rd.Snapshot)
-				rc.raftStorage.ApplySnapshot(rd.Snapshot)
+				rc.saveSnap(rd.Snapshot)                  //nolint:errcheck, revive // TODO: Handle an error returned.
+				rc.raftStorage.ApplySnapshot(rd.Snapshot) //nolint:errcheck,revive // TODO:: Handle an error returned.
 				rc.publishSnapshot(rd.Snapshot)
 
 				rc.recoverMembership(rd.Snapshot)
 			}
 
-			rc.raftStorage.Append(rd.Entries)
+			rc.raftStorage.Append(rd.Entries) //nolint:errcheck,revive // TODO:: Handle an error returned.
 
 			rc.transport.Send(rc.processMessages(rd.Messages))
 			if ok := rc.publishEntries(ctx, rc.entriesToApply(rd.CommittedEntries)); ok {

internal/metarepos/raft_metadata_repository.go

@@ -177,7 +177,7 @@ func (mr *RaftMetadataRepository) Run() {
 	mr.logger.Info("starting metadata repository")
 
 	mr.storage.Run()
-	mr.reportCollector.Run()
+	mr.reportCollector.Run() //nolint:errcheck,revive // TODO:: Handle an error returned.
 
 	mctx, cancel := mr.runner.WithManagedCancel(context.Background())
 
@@ -250,7 +250,7 @@ func (mr *RaftMetadataRepository) runDebugServer(ctx context.Context) {
 		IdleTimeout:  30 * time.Second,
 	}
 
-	defer mr.debugServer.Close()
+	defer mr.debugServer.Close() //nolint:errcheck,revive // TODO:: Handle an error returned.
 
 	httpMux.HandleFunc("/debug/pprof/", pprof.Index)
 	httpMux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
@@ -382,7 +382,7 @@ func (mr *RaftMetadataRepository) processReport(ctx context.Context) {
 			mr.muReportQueue.Unlock()
 
 			if reports != nil {
-				mr.propose(context.TODO(), reports, false)
+				mr.propose(context.TODO(), reports, false) //nolint:errcheck,revive // TODO:: Handle an error returned.
 			}
 		}
 	}
@@ -575,14 +575,15 @@ func (mr *RaftMetadataRepository) sendAck(nodeIndex uint64, requestNum uint64, e
 }
 
 func (mr *RaftMetadataRepository) apply(c *committedEntry) {
-	mr.withTelemetry(context.TODO(), "apply", func(ctx context.Context) (interface{}, error) {
+	mr.withTelemetry(context.TODO(), "apply", func(ctx context.Context) (interface{}, error) { //nolint:errcheck,revive // TODO:: Handle an error returned.
 		if c == nil || c.entry == nil {
 			return nil, nil
 		}
 
 		e := c.entry
 		f := e.Request.GetValue()
 
+		//nolint:errcheck,revive // TODO:: Handle an error returned.
 		switch r := f.(type) {
 		case *mrpb.RegisterStorageNode:
 			mr.applyRegisterStorageNode(r, e.NodeIndex, e.RequestIndex)
@@ -626,7 +627,7 @@ func (mr *RaftMetadataRepository) applyRegisterStorageNode(r *mrpb.RegisterStora
 		return err
 	}
 
-	mr.reportCollector.RegisterStorageNode(r.StorageNode)
+	mr.reportCollector.RegisterStorageNode(r.StorageNode) //nolint:errcheck,revive // TODO:: Handle an error returned.
 
 	return nil
 }
@@ -637,7 +638,7 @@ func (mr *RaftMetadataRepository) applyUnregisterStorageNode(r *mrpb.UnregisterS
 		return err
 	}
 
-	mr.reportCollector.UnregisterStorageNode(r.StorageNodeID)
+	mr.reportCollector.UnregisterStorageNode(r.StorageNodeID) //nolint:errcheck,revive // TODO:: Handle an error returned.
 
 	return nil
 }
@@ -986,7 +987,7 @@ func (mr *RaftMetadataRepository) applyCommit(r *mrpb.Commit, appliedIndex uint6
 		}
 
 		if trimVer != 0 && trimVer != math.MaxUint64 {
-			mr.storage.TrimLogStreamCommitHistory(trimVer)
+			mr.storage.TrimLogStreamCommitHistory(trimVer) //nolint:errcheck,revive // TODO:: Handle an error returned.
 		}
 
 		mr.reportCollector.Commit()
@@ -1008,7 +1009,7 @@ func (mr *RaftMetadataRepository) applyCommit(r *mrpb.Commit, appliedIndex uint6
 }
 
 func (mr *RaftMetadataRepository) applySeal(r *mrpb.Seal, nodeIndex, requestIndex, appliedIndex uint64) error {
-	mr.applyCommit(nil, appliedIndex)
+	mr.applyCommit(nil, appliedIndex) //nolint:errcheck,revive // TODO:: Handle an error returned.
 	err := mr.storage.SealingLogStream(r.LogStreamID, nodeIndex, requestIndex)
 	if err != nil {
 		return err
@@ -1167,7 +1168,7 @@ func (mr *RaftMetadataRepository) proposeCommit() {
 		NodeID:      mr.nodeID,
 		CreatedTime: time.Now(),
 	}
-	mr.propose(context.TODO(), r, false)
+	mr.propose(context.TODO(), r, false) //nolint:errcheck,revive // TODO:: Handle an error returned.
 }
 
 func (mr *RaftMetadataRepository) proposeReport(snID types.StorageNodeID, ur []snpb.LogStreamUncommitReport) error {
@@ -1438,7 +1439,7 @@ func (mr *RaftMetadataRepository) registerEndpoint(ctx context.Context) {
 		Url:    endpoint.(string),
 	}
 
-	mr.propose(ctx, r, true)
+	mr.propose(ctx, r, true) //nolint:errcheck,revive // TODO:: Handle an error returned.
 }
 
 func (mr *RaftMetadataRepository) GetClusterInfo(context.Context, types.ClusterID) (*mrpb.ClusterInfo, error) {