[#1374] tree: Use NewClient to create grpc connection in cache

Created grpc connection should be established, so perform Healthcheck request
to check connection is ok.

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

pkg/services/tree/cache.go

@@ -2,6 +2,7 @@ package tree
 
 import (
 	"context"
+	"crypto/ecdsa"
 	"errors"
 	"fmt"
 	"sync"
@@ -19,6 +20,7 @@ import (
 type clientCache struct {
 	sync.Mutex
 	simplelru.LRU[string, cacheItem]
+	key *ecdsa.PrivateKey
 }
 
 type cacheItem struct {
@@ -34,13 +36,14 @@ const (
 
 var errRecentlyFailed = errors.New("client has recently failed")
 
-func (c *clientCache) init() {
+func (c *clientCache) init(pk *ecdsa.PrivateKey) {
 	l, _ := simplelru.NewLRU(defaultClientCacheSize, func(_ string, value cacheItem) {
 		if conn := value.cc; conn != nil {
 			_ = conn.Close()
 		}
 	})
 	c.LRU = *l
+	c.key = pk
 }
 
 func (c *clientCache) get(ctx context.Context, netmapAddr string) (TreeServiceClient, error) {
@@ -63,7 +66,7 @@ func (c *clientCache) get(ctx context.Context, netmapAddr string) (TreeServiceCl
 		}
 	}
 
-	cc, err := dialTreeService(ctx, netmapAddr)
+	cc, err := c.dialTreeService(ctx, netmapAddr)
 	lastTry := time.Now()
 
 	c.Lock()
@@ -81,14 +84,13 @@ func (c *clientCache) get(ctx context.Context, netmapAddr string) (TreeServiceCl
 	return NewTreeServiceClient(cc), nil
 }
 
-func dialTreeService(ctx context.Context, netmapAddr string) (*grpc.ClientConn, error) {
+func (c *clientCache) dialTreeService(ctx context.Context, netmapAddr string) (*grpc.ClientConn, error) {
 	var netAddr network.Address
 	if err := netAddr.FromString(netmapAddr); err != nil {
 		return nil, err
 	}
 
 	opts := []grpc.DialOption{
-		grpc.WithBlock(),
 		grpc.WithChainUnaryInterceptor(
 			metrics.NewUnaryClientInterceptor(),
 			tracing.NewUnaryClientInteceptor(),
@@ -103,9 +105,24 @@ func dialTreeService(ctx context.Context, netmapAddr string) (*grpc.ClientConn,
 		opts = append(opts, grpc.WithTransportCredentials(insecure.NewCredentials()))
 	}
 
-	ctx, cancel := context.WithTimeout(ctx, defaultClientConnectTimeout)
-	cc, err := grpc.DialContext(ctx, netAddr.URIAddr(), opts...)
-	cancel()
+	req := &HealthcheckRequest{
+		Body: &HealthcheckRequest_Body{},
+	}
+	if err := SignMessage(req, c.key); err != nil {
+		return nil, err
+	}
 
-	return cc, err
+	cc, err := grpc.NewClient(netAddr.URIAddr(), opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, defaultClientConnectTimeout)
+	defer cancel()
+	// perform some request to check connection
+	if _, err := NewTreeServiceClient(cc).Healthcheck(ctx, req); err != nil {
+		_ = cc.Close()
+		return nil, err
+	}
+	return cc, nil
 }

pkg/services/tree/service.go

@@ -65,7 +65,7 @@ func New(opts ...Option) *Service {
 		s.log = &logger.Logger{Logger: zap.NewNop()}
 	}
 
-	s.cache.init()
+	s.cache.init(s.key)
 	s.closeCh = make(chan struct{})
 	s.replicateCh = make(chan movePair, s.replicatorChannelCapacity)
 	s.replicateLocalCh = make(chan applyOp)