From 880f3a61e553ed7fe8f76b35a1c3b7b77dfb4599 Mon Sep 17 00:00:00 2001
From: Denis Kirillov <denis@nspcc.ru>
Date: Tue, 7 Sep 2021 17:34:20 +0300
Subject: [PATCH] [#32] Require at least one healthy node

Signed-off-by: Denis Kirillov <denis@nspcc.ru>
---
 pool/pool.go      | 19 ++++++++++---
 pool/pool_test.go | 69 ++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 82 insertions(+), 6 deletions(-)

diff --git a/pool/pool.go b/pool/pool.go
index 1c89ca6e..ba71fa14 100644
--- a/pool/pool.go
+++ b/pool/pool.go
@@ -16,6 +16,7 @@ import (
 	"github.com/nspcc-dev/neofs-api-go/pkg/object"
 	"github.com/nspcc-dev/neofs-api-go/pkg/owner"
 	"github.com/nspcc-dev/neofs-api-go/pkg/session"
+	"go.uber.org/zap"
 )
 
 // Client is a wrapper for client.Client to generate mock.
@@ -26,6 +27,7 @@ type Client interface {
 // BuilderOptions contains options used to build connection pool.
 type BuilderOptions struct {
 	Key                     *ecdsa.PrivateKey
+	Logger                  *zap.Logger
 	NodeConnectionTimeout   time.Duration
 	NodeRequestTimeout      time.Duration
 	ClientRebalanceInterval time.Duration
@@ -105,6 +107,7 @@ type pool struct {
 
 func newPool(ctx context.Context, options *BuilderOptions) (Pool, error) {
 	clientPacks := make([]*clientPack, len(options.weights))
+	var atLeastOneHealthy bool
 	for i, address := range options.addresses {
 		c, err := options.clientBuilder(client.WithDefaultPrivateKey(options.Key),
 			client.WithURIAddress(address, nil),
@@ -112,12 +115,22 @@ func newPool(ctx context.Context, options *BuilderOptions) (Pool, error) {
 		if err != nil {
 			return nil, err
 		}
+		var healthy bool
 		st, err := c.CreateSession(ctx, options.SessionExpirationEpoch)
-		if err != nil {
-			return nil, fmt.Errorf("failed to create neofs session token for client %v: %w", address, err)
+		if err != nil && options.Logger != nil {
+			options.Logger.Warn("failed to create neofs session token for client",
+				zap.String("address", address),
+				zap.Error(err))
+		} else if err == nil {
+			healthy, atLeastOneHealthy = true, true
 		}
-		clientPacks[i] = &clientPack{client: c, sessionToken: st, healthy: true}
+		clientPacks[i] = &clientPack{client: c, sessionToken: st, healthy: healthy}
 	}
+
+	if !atLeastOneHealthy {
+		return nil, fmt.Errorf("at least one node must be healthy")
+	}
+
 	source := rand.NewSource(time.Now().UnixNano())
 	sampler := NewSampler(options.weights, source)
 	wallet, err := owner.NEO3WalletFromPublicKey(&options.Key.PublicKey)
diff --git a/pool/pool_test.go b/pool/pool_test.go
index 5d690d9c..a6e93585 100644
--- a/pool/pool_test.go
+++ b/pool/pool_test.go
@@ -14,6 +14,7 @@ import (
 	"github.com/nspcc-dev/neofs-api-go/pkg/netmap"
 	"github.com/nspcc-dev/neofs-api-go/pkg/session"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
 )
 
 func TestBuildPoolClientFailed(t *testing.T) {
@@ -48,8 +49,8 @@ func TestBuildPoolCreateSessionFailed(t *testing.T) {
 
 	clientBuilder := func(opts ...client.Option) (client.Client, error) {
 		mockClient := NewMockClient(ctrl)
-		mockClient.EXPECT().CreateSession(gomock.Any(), gomock.Any()).Return(nil, fmt.Errorf("error session"))
-		mockClient.EXPECT().EndpointInfo(gomock.Any(), gomock.Any()).Return(&client.EndpointInfo{}, nil)
+		mockClient.EXPECT().CreateSession(gomock.Any(), gomock.Any()).Return(nil, fmt.Errorf("error session")).AnyTimes()
+		mockClient.EXPECT().EndpointInfo(gomock.Any(), gomock.Any()).Return(&client.EndpointInfo{}, nil).AnyTimes()
 		return mockClient, nil
 	}
 
@@ -63,7 +64,69 @@ func TestBuildPoolCreateSessionFailed(t *testing.T) {
 
 	_, err = pb.Build(context.TODO(), opts)
 	require.Error(t, err)
-	require.Contains(t, err.Error(), "client []: error session")
+}
+
+func TestBuildPoolOneNodeFailed(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	ctrl2 := gomock.NewController(t)
+	defer ctrl2.Finish()
+
+	key, err := keys.NewPrivateKey()
+	require.NoError(t, err)
+
+	ni := &netmap.NodeInfo{}
+	ni.SetAddresses("addr1", "addr2")
+
+	var expectedToken *session.Token
+	clientCount := -1
+	clientBuilder := func(opts ...client.Option) (client.Client, error) {
+		clientCount++
+		mockClient := NewMockClient(ctrl)
+		mockInvokes := 0
+		mockClient.EXPECT().CreateSession(gomock.Any(), gomock.Any()).DoAndReturn(func(_, _ interface{}, _ ...interface{}) (*session.Token, error) {
+			mockInvokes++
+			if mockInvokes == 1 {
+				expectedToken = newToken(t)
+				return nil, fmt.Errorf("error session")
+			}
+			return expectedToken, nil
+		}).AnyTimes()
+
+		mockClient.EXPECT().EndpointInfo(gomock.Any(), gomock.Any()).Return(nil, nil).AnyTimes()
+
+		mockClient2 := NewMockClient(ctrl2)
+		mockClient2.EXPECT().CreateSession(gomock.Any(), gomock.Any()).Return(nil, nil).AnyTimes()
+		mockClient2.EXPECT().EndpointInfo(gomock.Any(), gomock.Any()).Return(nil, nil).AnyTimes()
+
+		if clientCount == 0 {
+			return mockClient, nil
+		}
+		return mockClient2, nil
+	}
+
+	pb := new(Builder)
+	pb.AddNode("peer0", 9)
+	pb.AddNode("peer1", 1)
+
+	log, err := zap.NewProduction()
+	require.NoError(t, err)
+	opts := &BuilderOptions{
+		Key:                     &key.PrivateKey,
+		clientBuilder:           clientBuilder,
+		ClientRebalanceInterval: 1000 * time.Millisecond,
+		Logger:                  log,
+	}
+
+	clientPool, err := pb.Build(context.TODO(), opts)
+	require.NoError(t, err)
+
+	condition := func() bool {
+		_, st, err := clientPool.Connection()
+		return err == nil && st == expectedToken
+	}
+	require.Never(t, condition, 900*time.Millisecond, 100*time.Millisecond)
+	require.Eventually(t, condition, 3*time.Second, 300*time.Millisecond)
 }
 
 func TestBuildPoolZeroNodes(t *testing.T) {