[#84] pool/tree: Allow to pass gRPC dial options

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

pool/tree/pool.go

@@ -17,7 +17,6 @@ import (
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/credentials/insecure"
 )
 
 const (
@@ -57,6 +56,7 @@ type InitParameters struct {
 	healthcheckTimeout      time.Duration
 	clientRebalanceInterval time.Duration
 	nodeParams              []pool.NodeParam
+	dialOptions             []grpc.DialOption
 }
 
 // Pool represents virtual connection to the FrostFS tree services network to communicate
@@ -72,6 +72,7 @@ type Pool struct {
 	cancel          context.CancelFunc
 	closedCh        chan struct{}
 	rebalanceParams rebalanceParameters
+	dialOptions     []grpc.DialOption
 	logger          *zap.Logger
 
 	startIndicesMtx sync.RWMutex
@@ -167,6 +168,7 @@ func NewPool(options InitParameters) (*Pool, error) {
 	p := &Pool{
 		key:         options.key,
 		logger:      options.logger,
+		dialOptions: options.dialOptions,
 		rebalanceParams: rebalanceParameters{
 			nodesGroup:              nodesParams,
 			nodeRequestTimeout:      options.healthcheckTimeout,
@@ -192,7 +194,7 @@ func (p *Pool) Dial(ctx context.Context) error {
 	for i, nodes := range p.rebalanceParams.nodesGroup {
 		clients := make([]client, len(nodes))
 		for j, node := range nodes {
-			clients[j] = newTreeClient(node.Address(), grpc.WithTransportCredentials(insecure.NewCredentials()))
+			clients[j] = newTreeClient(node.Address(), p.dialOptions...)
 			if err := clients[j].dial(ctx); err != nil {
 				p.log(zap.WarnLevel, "failed to build client", zap.String("address", node.Address()), zap.Error(err))
 				continue
@@ -258,6 +260,11 @@ func (x *InitParameters) AddNode(nodeParam pool.NodeParam) {
 	x.nodeParams = append(x.nodeParams, nodeParam)
 }
 
+// SetGRPCDialOptions sets the gRPC dial options for new gRPC tree client connection.
+func (x *InitParameters) SetGRPCDialOptions(opts ...grpc.DialOption) {
+	x.dialOptions = opts
+}
+
 // GetNodes invokes eponymous method from TreeServiceClient.
 //
 // Can return predefined errors: