[#569] cli: Add control shards writecache seal command

It does the same as `control shards flush-writecache --seal`, but
has better name.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/local_object_storage/engine/writecache.go

@@ -2,6 +2,7 @@ package engine
 
 import (
 	"context"
+	"sync"
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/shard"
@@ -11,6 +12,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/trace"
+	"golang.org/x/sync/errgroup"
 )
 
 // FlushWriteCachePrm groups the parameters of FlushWriteCache operation.
@@ -44,7 +46,7 @@ type FlushWriteCacheRes struct{}
 func (e *StorageEngine) FlushWriteCache(ctx context.Context, p FlushWriteCachePrm) (FlushWriteCacheRes, error) {
 	ctx, span := tracing.StartSpanFromContext(ctx, "StorageEngine.FlushWriteCache",
 		trace.WithAttributes(
-			attribute.String("shard)id", p.shardID.String()),
+			attribute.String("shard_id", p.shardID.String()),
 			attribute.Bool("ignore_errors", p.ignoreErrors),
 			attribute.Bool("seal", p.seal),
 		))
@@ -65,6 +67,79 @@ func (e *StorageEngine) FlushWriteCache(ctx context.Context, p FlushWriteCachePr
 	return FlushWriteCacheRes{}, sh.FlushWriteCache(ctx, prm)
 }
 
+type SealWriteCachePrm struct {
+	ShardIDs     []*shard.ID
+	IgnoreErrors bool
+}
+
+type ShardSealResult struct {
+	ShardID  *shard.ID
+	Success  bool
+	ErrorMsg string
+}
+
+type SealWriteCacheRes struct {
+	ShardResults []ShardSealResult
+}
+
+// SealWriteCache flushed all data to blobstore and moves write-cache to degraded read only mode.
+func (e *StorageEngine) SealWriteCache(ctx context.Context, prm SealWriteCachePrm) (SealWriteCacheRes, error) {
+	ctx, span := tracing.StartSpanFromContext(ctx, "StorageEngine.SealWriteCache",
+		trace.WithAttributes(
+			attribute.Int("shard_id_count", len(prm.ShardIDs)),
+			attribute.Bool("ignore_errors", prm.IgnoreErrors),
+		))
+	defer span.End()
+
+	res := SealWriteCacheRes{
+		ShardResults: make([]ShardSealResult, 0, len(prm.ShardIDs)),
+	}
+	resGuard := &sync.Mutex{}
+
+	eg, egCtx := errgroup.WithContext(ctx)
+	for _, shardID := range prm.ShardIDs {
+		shardID := shardID
+		eg.Go(func() error {
+			e.mtx.RLock()
+			sh, ok := e.shards[shardID.String()]
+			e.mtx.RUnlock()
+
+			if !ok {
+				resGuard.Lock()
+				defer resGuard.Unlock()
+				res.ShardResults = append(res.ShardResults, ShardSealResult{
+					ShardID:  shardID,
+					ErrorMsg: errShardNotFound.Error(),
+				})
+				return nil
+			}
+
+			err := sh.SealWriteCache(egCtx, shard.SealWriteCachePrm{IgnoreErrors: prm.IgnoreErrors})
+
+			resGuard.Lock()
+			defer resGuard.Unlock()
+
+			if err != nil {
+				res.ShardResults = append(res.ShardResults, ShardSealResult{
+					ShardID:  shardID,
+					ErrorMsg: err.Error(),
+				})
+			} else {
+				res.ShardResults = append(res.ShardResults, ShardSealResult{
+					ShardID: shardID,
+					Success: true,
+				})
+			}
+			return nil
+		})
+	}
+
+	if err := eg.Wait(); err != nil {
+		return SealWriteCacheRes{}, err
+	}
+	return res, nil
+}
+
 type writeCacheMetrics struct {
 	shardID string
 	metrics metrics.WriteCacheMetrics