Merge pull request #5 from masterSplinter01/feature/4-import-refactor-connection-pooling

Import refactor connection pooling

go.mod

@@ -5,5 +5,8 @@ go 1.16
 require (
 	github.com/alecthomas/participle v0.7.1
 	github.com/nspcc-dev/neofs-api-go v1.26.1
+	github.com/nspcc-dev/neofs-crypto v0.3.0
 	github.com/stretchr/testify v1.6.1
+	go.uber.org/zap v1.10.0
+	google.golang.org/grpc v1.29.1
 )

go.sum

@@ -23,6 +23,7 @@ github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/btcsuite/btcd v0.20.1-beta h1:Ik4hyJqN8Jfyv3S4AGBOmyouMsYE3EdYODkMbQjwPGw=
 github.com/btcsuite/btcd v0.20.1-beta/go.mod h1:wVuoA8VJLEcwgqHBwHmzLRazpKxTv13Px/pDuV7OomQ=
 github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f/go.mod h1:TdznJufoqS23FtqVCzL0ZqgP5MqXbb4fg/WgDys70nA=
 github.com/btcsuite/btcutil v0.0.0-20190425235716-9e5f4b9a998d/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
@@ -86,10 +87,13 @@ github.com/gomodule/redigo v2.0.0+incompatible/go.mod h1:B4C85qUVwatsJoIUNIfCRsp
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/hashicorp/golang-lru v0.5.4 h1:YDjusn29QI/Das2iO9M0BHnIbxPeyuCHsjMW+lJfyTc=
 github.com/hashicorp/golang-lru v0.5.4/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
@@ -103,8 +107,10 @@ github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23/go.mod h1:J+Gs4SYgM6
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pretty v0.2.0 h1:s5hAObm+yFO5uHYt5dYjxi2rXrsnmRpJx4OYvIWUaQs=
 github.com/kr/pretty v0.2.0/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mattn/go-colorable v0.1.2/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
@@ -119,6 +125,7 @@ github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJ
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
+github.com/mr-tron/base58 v1.1.2 h1:ZEw4I2EgPKDJ2iEw0cNmLB3ROrEmkOtXIkaG7wZg+78=
 github.com/mr-tron/base58 v1.1.2/go.mod h1:BinMc/sQntlIE1frQmRFPUoPA1Zkr8VRgBdjWI2mNwc=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/nspcc-dev/dbft v0.0.0-20191205084618-dacb1a30c254/go.mod h1:w1Ln2aT+dBlPhLnuZhBV+DfPEdS2CHWWLp5JTScY3bw=
@@ -131,14 +138,17 @@ github.com/nspcc-dev/hrw v1.0.9 h1:17VcAuTtrstmFppBjfRiia4K2wA/ukXZhLFS8Y8rz5Y=
 github.com/nspcc-dev/hrw v1.0.9/go.mod h1:l/W2vx83vMQo6aStyx2AuZrJ+07lGv2JQGlVkPG06MU=
 github.com/nspcc-dev/neo-go v0.73.1-pre.0.20200303142215-f5a1b928ce09/go.mod h1:pPYwPZ2ks+uMnlRLUyXOpLieaDQSEaf4NM3zHVbRjmg=
 github.com/nspcc-dev/neo-go v0.91.0/go.mod h1:G6HdOWvzQ6tlvFdvFSN/PgCzLPN/X/X4d5hTjFRUDcc=
+github.com/nspcc-dev/neo-go v0.95.0 h1:bttArYkIuhBJWSZsZ1xVW8MJsj5SvZwAhqVN3HZPNbo=
 github.com/nspcc-dev/neo-go v0.95.0/go.mod h1:bW07ge1WFXsBgqrcPpLUr6OcyQxHqM26MZNesWMdH0c=
 github.com/nspcc-dev/neofs-api-go v1.24.0/go.mod h1:G7dqincfdjBrAbL5nxVp82emF05fSVEqe59ICsoRDI8=
 github.com/nspcc-dev/neofs-api-go v1.26.1 h1:GMIuEB6Hv9IXP9SJd/1f8Df6gRriPkSplpmpJXgQ/1I=
 github.com/nspcc-dev/neofs-api-go v1.26.1/go.mod h1:SHuH1Ba3U/h3j+8HHbb3Cns1LfMlEb88guWog9Qi68Y=
 github.com/nspcc-dev/neofs-crypto v0.2.0/go.mod h1:F/96fUzPM3wR+UGsPi3faVNmFlA9KAEAUQR7dMxZmNA=
 github.com/nspcc-dev/neofs-crypto v0.2.3/go.mod h1:8w16GEJbH6791ktVqHN9YRNH3s9BEEKYxGhlFnp0cDw=
+github.com/nspcc-dev/neofs-crypto v0.3.0 h1:zlr3pgoxuzrmGCxc5W8dGVfA9Rro8diFvVnBg0L4ifM=
 github.com/nspcc-dev/neofs-crypto v0.3.0/go.mod h1:8w16GEJbH6791ktVqHN9YRNH3s9BEEKYxGhlFnp0cDw=
 github.com/nspcc-dev/rfc6979 v0.1.0/go.mod h1:exhIh1PdpDC5vQmyEsGvc4YDM/lyQp/452QxGq/UEso=
+github.com/nspcc-dev/rfc6979 v0.2.0 h1:3e1WNxrN60/6N0DW7+UYisLeZJyfqZTNOjeV/toYvOE=
 github.com/nspcc-dev/rfc6979 v0.2.0/go.mod h1:exhIh1PdpDC5vQmyEsGvc4YDM/lyQp/452QxGq/UEso=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
@@ -150,6 +160,7 @@ github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/9
 github.com/pierrec/lz4 v2.5.2+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi+IEE17M5jbnwPHcY=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
@@ -192,13 +203,17 @@ github.com/yuin/gopher-lua v0.0.0-20190514113301-1cd887cd7036/go.mod h1:gqRgreBU
 github.com/yuin/gopher-lua v0.0.0-20191128022950-c6266f4fe8d7/go.mod h1:gqRgreBUhTSL0GeU64rtZ3Uq3wtjOa/TB2YfrtkCbVQ=
 go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.etcd.io/bbolt v1.3.4/go.mod h1:G5EMThwa9y8QZGBClrRx5EY+Yw9kAhnjy3bSjsnlVTQ=
+go.uber.org/atomic v1.4.0 h1:cxzIVoETapQEqDhQu3QfnvXAV4AlzcvUCxkVUFw3+EU=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
+go.uber.org/multierr v1.1.0 h1:HoEmRHQPVSqub6w2z2d2EOVs2fjyFRGyofhKuyDq0QI=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
+go.uber.org/zap v1.10.0 h1:ORx85nbTijNz8ljznvCMR1ZBIPKFn3jQrag10X2AsuM=
 go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4 h1:HuIa8hRrWRSrqYzx1qI49NNxhdi2PrY7gxVSq1JjLDc=
 golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -245,6 +260,7 @@ golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGm
 golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20190524140312-2c0ae7006135/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
@@ -266,6 +282,7 @@ google.golang.org/protobuf v1.23.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2
 gopkg.in/abiosoft/ishell.v2 v2.0.0/go.mod h1:sFp+cGtH6o4s1FtpVPTMcHq2yue+c4DGOVohJCPUzwY=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=

pkg/logger/grpc.go

@@ -0,0 +1,78 @@
+package logger
+
+import (
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"google.golang.org/grpc/grpclog"
+)
+
+type (
+	zapLogger struct {
+		zapcore.Core
+		log *zap.SugaredLogger
+	}
+
+	// Logger includes grpclog.LoggerV2 interface with an additional
+	// Println method.
+	Logger interface {
+		grpclog.LoggerV2
+		Println(v ...interface{})
+	}
+)
+
+// GRPC wraps given zap.Logger into grpclog.LoggerV2+ interface.
+func GRPC(l *zap.Logger) Logger {
+	log := l.WithOptions(
+		// skip gRPCLog + zapLogger in caller
+		zap.AddCallerSkip(2))
+
+	return &zapLogger{
+		Core: log.Core(),
+		log:  log.Sugar(),
+	}
+}
+
+// Info implements grpclog.LoggerV2.
+func (z *zapLogger) Info(args ...interface{}) { z.log.Info(args...) }
+
+// Infoln implements grpclog.LoggerV2.
+func (z *zapLogger) Infoln(args ...interface{}) { z.log.Info(args...) }
+
+// Infof implements grpclog.LoggerV2.
+func (z *zapLogger) Infof(format string, args ...interface{}) { z.log.Infof(format, args...) }
+
+// Println allows to print a line with info severity.
+func (z *zapLogger) Println(args ...interface{}) { z.log.Info(args...) }
+
+// Printf implements grpclog.LoggerV2.
+func (z *zapLogger) Printf(format string, args ...interface{}) { z.log.Infof(format, args...) }
+
+// Warning implements grpclog.LoggerV2.
+func (z *zapLogger) Warning(args ...interface{}) { z.log.Warn(args...) }
+
+// Warningln implements grpclog.LoggerV2.
+func (z *zapLogger) Warningln(args ...interface{}) { z.log.Warn(args...) }
+
+// Warningf implements grpclog.LoggerV2.
+func (z *zapLogger) Warningf(format string, args ...interface{}) { z.log.Warnf(format, args...) }
+
+// Error implements grpclog.LoggerV2.
+func (z *zapLogger) Error(args ...interface{}) { z.log.Error(args...) }
+
+// Errorln implements grpclog.LoggerV2.
+func (z *zapLogger) Errorln(args ...interface{}) { z.log.Error(args...) }
+
+// Errorf implements grpclog.LoggerV2.
+func (z *zapLogger) Errorf(format string, args ...interface{}) { z.log.Errorf(format, args...) }
+
+// Fatal implements grpclog.LoggerV2.
+func (z *zapLogger) Fatal(args ...interface{}) { z.log.Fatal(args...) }
+
+// Fatalln implements grpclog.LoggerV2.
+func (z *zapLogger) Fatalln(args ...interface{}) { z.log.Fatal(args...) }
+
+// Fatalf implements grpclog.LoggerV2.
+func (z *zapLogger) Fatalf(format string, args ...interface{}) { z.log.Fatalf(format, args...) }
+
+// V implements grpclog.LoggerV2.
+func (z *zapLogger) V(int) bool { return z.Enabled(zapcore.DebugLevel) }

pkg/logger/option.go

@@ -0,0 +1,33 @@
+package logger
+
+import "go.uber.org/zap"
+
+// WithSamplingInitial returns Option that sets sampling initial parameter.
+func WithSamplingInitial(v int) Option { return func(o *options) { o.SamplingInitial = v } }
+
+// WithSamplingThereafter returns Option that sets sampling thereafter parameter.
+func WithSamplingThereafter(v int) Option { return func(o *options) { o.SamplingThereafter = v } }
+
+// WithFormat returns Option that sets format parameter.
+func WithFormat(v string) Option { return func(o *options) { o.Format = v } }
+
+// WithLevel returns Option that sets Level parameter.
+func WithLevel(v string) Option { return func(o *options) { o.Level = v } }
+
+// WithTraceLevel returns Option that sets trace level parameter.
+func WithTraceLevel(v string) Option { return func(o *options) { o.TraceLevel = v } }
+
+// WithoutDisclaimer returns Option that disables disclaimer.
+func WithoutDisclaimer() Option { return func(o *options) { o.NoDisclaimer = true } }
+
+// WithoutCaller returns Option that disables caller printing.
+func WithoutCaller() Option { return func(o *options) { o.NoCaller = true } }
+
+// WithAppName returns Option that sets application name.
+func WithAppName(v string) Option { return func(o *options) { o.AppName = v } }
+
+// WithAppVersion returns Option that sets application version.
+func WithAppVersion(v string) Option { return func(o *options) { o.AppVersion = v } }
+
+// WithZapOptions returns Option that sets zap logger options.
+func WithZapOptions(opts ...zap.Option) Option { return func(o *options) { o.Options = opts } }

pkg/logger/zap.go

@@ -0,0 +1,134 @@
+package logger
+
+import (
+	"strings"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+type (
+	// Option represents logger option setter.
+	Option func(o *options)
+
+	options struct {
+		Options []zap.Option
+
+		SamplingInitial    int
+		SamplingThereafter int
+
+		Format     string
+		Level      string
+		TraceLevel string
+
+		NoCaller     bool
+		NoDisclaimer bool
+
+		AppName    string
+		AppVersion string
+	}
+)
+
+const (
+	formatJSON    = "json"
+	formatConsole = "console"
+
+	defaultSamplingInitial    = 100
+	defaultSamplingThereafter = 100
+
+	lvlInfo  = "info"
+	lvlWarn  = "warn"
+	lvlDebug = "debug"
+	lvlError = "error"
+	lvlFatal = "fatal"
+	lvlPanic = "panic"
+)
+
+func safeLevel(lvl string) zap.AtomicLevel {
+	switch strings.ToLower(lvl) {
+	case lvlDebug:
+		return zap.NewAtomicLevelAt(zap.DebugLevel)
+	case lvlWarn:
+		return zap.NewAtomicLevelAt(zap.WarnLevel)
+	case lvlError:
+		return zap.NewAtomicLevelAt(zap.ErrorLevel)
+	case lvlFatal:
+		return zap.NewAtomicLevelAt(zap.FatalLevel)
+	case lvlPanic:
+		return zap.NewAtomicLevelAt(zap.PanicLevel)
+	default:
+		return zap.NewAtomicLevelAt(zap.InfoLevel)
+	}
+}
+
+func defaults() *options {
+	return &options{
+		SamplingInitial:    defaultSamplingInitial,
+		SamplingThereafter: defaultSamplingThereafter,
+
+		Format:     formatConsole,
+		Level:      lvlDebug,
+		TraceLevel: lvlInfo,
+
+		NoCaller:     false,
+		NoDisclaimer: false,
+
+		AppName:    "",
+		AppVersion: "",
+	}
+}
+
+// New returns new zap.Logger using all options specified and stdout used
+// for output.
+func New(opts ...Option) (*zap.Logger, error) {
+	o := defaults()
+	c := zap.NewProductionConfig()
+
+	c.OutputPaths = []string{"stdout"}
+	c.ErrorOutputPaths = []string{"stdout"}
+
+	for _, opt := range opts {
+		opt(o)
+	}
+
+	// set sampling
+	c.Sampling = &zap.SamplingConfig{
+		Initial:    o.SamplingInitial,
+		Thereafter: o.SamplingThereafter,
+	}
+
+	// logger level
+	c.Level = safeLevel(o.Level)
+	traceLvl := safeLevel(o.TraceLevel)
+
+	// logger format
+	switch f := o.Format; strings.ToLower(f) {
+	case formatConsole:
+		c.Encoding = formatConsole
+	default:
+		c.Encoding = formatJSON
+	}
+
+	// logger time
+	c.EncoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
+
+	if o.NoCaller {
+		c.EncoderConfig.EncodeCaller = nil
+	}
+
+	// enable trace only for current log-level
+	o.Options = append(o.Options, zap.AddStacktrace(traceLvl))
+
+	l, err := c.Build(o.Options...)
+	if err != nil {
+		return nil, err
+	}
+
+	if o.NoDisclaimer {
+		return l, nil
+	}
+
+	return l.With(
+		zap.String("app_name", o.AppName),
+		zap.String("app_version", o.AppVersion)), nil
+}

pkg/neofs/client-plant.go

@@ -0,0 +1,39 @@
+package neofs
+
+import (
+	"context"
+	"crypto/ecdsa"
+
+	"github.com/nspcc-dev/neofs-api-go/pkg/client"
+	"github.com/nspcc-dev/neofs-api-go/pkg/owner"
+	"github.com/nspcc-dev/neofs-api-go/pkg/token"
+	"github.com/nspcc-dev/neofs-sdk-go/pkg/pool"
+)
+
+// ClientPlant provides connections to NeoFS nodes from pool and allows to
+// get local owner ID.
+type ClientPlant interface {
+	ConnectionArtifacts() (client.Client, *token.SessionToken, error)
+	OwnerID() *owner.ID
+}
+
+type neofsClientPlant struct {
+	key     *ecdsa.PrivateKey
+	ownerID *owner.ID
+	pool    pool.Pool
+}
+
+// ConnectionArtifacts returns connection from pool.
+func (cp *neofsClientPlant) ConnectionArtifacts() (client.Client, *token.SessionToken, error) {
+	return cp.pool.ConnectionArtifacts()
+}
+
+// OwnerID returns plant's owner ID.
+func (cp *neofsClientPlant) OwnerID() *owner.ID {
+	return cp.ownerID
+}
+
+// NewClientPlant creates new ClientPlant from given context, pool and credentials.
+func NewClientPlant(ctx context.Context, pool pool.Pool, creds Credentials) (ClientPlant, error) {
+	return &neofsClientPlant{key: creds.PrivateKey(), ownerID: creds.Owner(), pool: pool}, nil
+}

pkg/neofs/credentials.go

@@ -0,0 +1,78 @@
+package neofs
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"math/big"
+
+	"github.com/nspcc-dev/neofs-api-go/pkg/owner"
+	crypto "github.com/nspcc-dev/neofs-crypto"
+)
+
+type (
+	// Credentials contains methods that needed to work with NeoFS.
+	Credentials interface {
+		Owner() *owner.ID
+		PublicKey() *ecdsa.PublicKey
+		PrivateKey() *ecdsa.PrivateKey
+	}
+
+	credentials struct {
+		key     *ecdsa.PrivateKey
+		ownerID *owner.ID
+	}
+)
+
+// NewCredentials creates an instance of Credentials through string
+// representation of secret. It allows passing WIF, path, hex-encoded and others.
+func NewCredentials(secret string) (Credentials, error) {
+	key, err := crypto.LoadPrivateKey(secret)
+	if err != nil {
+		return nil, err
+	}
+	return setFromPrivateKey(key)
+}
+
+// NewEphemeralCredentials creates new private key and Credentials based on that
+// key.
+func NewEphemeralCredentials() (Credentials, error) {
+	c := elliptic.P256()
+	priv, x, y, err := elliptic.GenerateKey(c, rand.Reader)
+	if err != nil {
+		return nil, err
+	}
+	key := &ecdsa.PrivateKey{
+		PublicKey: ecdsa.PublicKey{
+			Curve: c,
+			X:     x,
+			Y:     y,
+		},
+		D: new(big.Int).SetBytes(priv),
+	}
+	return setFromPrivateKey(key)
+}
+
+// PrivateKey returns ecdsa.PrivateKey.
+func (c *credentials) PrivateKey() *ecdsa.PrivateKey {
+	return c.key
+}
+
+// PublicKey returns ecdsa.PublicKey.
+func (c *credentials) PublicKey() *ecdsa.PublicKey {
+	return &c.key.PublicKey
+}
+
+// Owner returns owner.ID.
+func (c *credentials) Owner() *owner.ID {
+	return c.ownerID
+}
+
+func setFromPrivateKey(key *ecdsa.PrivateKey) (*credentials, error) {
+	wallet, err := owner.NEO3WalletFromPublicKey(&key.PublicKey)
+	if err != nil {
+		return nil, err
+	}
+	ownerID := owner.NewIDFromNeo3Wallet(wallet)
+	return &credentials{key: key, ownerID: ownerID}, nil
+}

pkg/pool/pool.go

@@ -0,0 +1,160 @@
+package pool
+
+import (
+	"context"
+	"crypto/ecdsa"
+	"errors"
+	"fmt"
+	"math/rand"
+	"sync"
+	"time"
+
+	"github.com/nspcc-dev/neofs-api-go/pkg/client"
+	"github.com/nspcc-dev/neofs-api-go/pkg/token"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/keepalive"
+)
+
+// BuilderOptions contains options used to build connection pool.
+type BuilderOptions struct {
+	Key                     *ecdsa.PrivateKey
+	NodeConnectionTimeout   time.Duration
+	NodeRequestTimeout      time.Duration
+	ClientRebalanceInterval time.Duration
+	KeepaliveTime           time.Duration
+	KeepaliveTimeout        time.Duration
+	KeepalivePermitWoStream bool
+	SessionExpirationEpoch  uint64
+	weights                 []float64
+	connections             []*grpc.ClientConn
+}
+
+// Builder is an interim structure used to collect node addresses/weights and
+// build connection pool subsequently.
+type Builder struct {
+	addresses []string
+	weights   []float64
+}
+
+// AddNode adds address/weight pair to node PoolBuilder list.
+func (pb *Builder) AddNode(address string, weight float64) *Builder {
+	pb.addresses = append(pb.addresses, address)
+	pb.weights = append(pb.weights, weight)
+	return pb
+}
+
+// Build creates new pool based on current PoolBuilder state and options.
+func (pb *Builder) Build(ctx context.Context, options *BuilderOptions) (Pool, error) {
+	if len(pb.addresses) == 0 {
+		return nil, errors.New("no NeoFS peers configured")
+	}
+	totalWeight := 0.0
+	for _, w := range pb.weights {
+		totalWeight += w
+	}
+	for i, w := range pb.weights {
+		pb.weights[i] = w / totalWeight
+	}
+	var cons = make([]*grpc.ClientConn, len(pb.addresses))
+	for i, address := range pb.addresses {
+		con, err := func() (*grpc.ClientConn, error) {
+			toctx, c := context.WithTimeout(ctx, options.NodeConnectionTimeout)
+			defer c()
+			return grpc.DialContext(toctx, address,
+				grpc.WithInsecure(),
+				grpc.WithBlock(),
+				grpc.WithKeepaliveParams(keepalive.ClientParameters{
+					Time:                options.KeepaliveTime,
+					Timeout:             options.KeepaliveTimeout,
+					PermitWithoutStream: options.KeepalivePermitWoStream,
+				}),
+			)
+		}()
+		if err != nil {
+			return nil, err
+		}
+		cons[i] = con
+	}
+	options.weights = pb.weights
+	options.connections = cons
+	return new(ctx, options)
+}
+
+// Pool is an interface providing connection artifacts on request.
+type Pool interface {
+	ConnectionArtifacts() (client.Client, *token.SessionToken, error)
+}
+
+type clientPack struct {
+	client       client.Client
+	sessionToken *token.SessionToken
+	healthy      bool
+}
+
+type pool struct {
+	lock        sync.RWMutex
+	sampler     *Sampler
+	clientPacks []*clientPack
+}
+
+func new(ctx context.Context, options *BuilderOptions) (Pool, error) {
+	clientPacks := make([]*clientPack, len(options.weights))
+	for i, con := range options.connections {
+		c, err := client.New(client.WithDefaultPrivateKey(options.Key), client.WithGRPCConnection(con))
+		if err != nil {
+			return nil, err
+		}
+		st, err := c.CreateSession(ctx, options.SessionExpirationEpoch)
+		if err != nil {
+			address := "unknown"
+			if epi, err := c.EndpointInfo(ctx); err == nil {
+				address = epi.NodeInfo().Address()
+			}
+			return nil, fmt.Errorf("failed to create neofs session token for client %s: %w", address, err)
+		}
+		clientPacks[i] = &clientPack{client: c, sessionToken: st, healthy: true}
+	}
+	source := rand.NewSource(time.Now().UnixNano())
+	sampler := NewSampler(options.weights, source)
+	pool := &pool{sampler: sampler, clientPacks: clientPacks}
+	go func() {
+		ticker := time.NewTimer(options.ClientRebalanceInterval)
+		for range ticker.C {
+			ok := true
+			for i, clientPack := range pool.clientPacks {
+				func() {
+					tctx, c := context.WithTimeout(ctx, options.NodeRequestTimeout)
+					defer c()
+					if _, err := clientPack.client.EndpointInfo(tctx); err != nil {
+						ok = false
+					}
+					pool.lock.Lock()
+					pool.clientPacks[i].healthy = ok
+					pool.lock.Unlock()
+				}()
+			}
+			ticker.Reset(options.ClientRebalanceInterval)
+		}
+	}()
+	return pool, nil
+}
+
+func (p *pool) ConnectionArtifacts() (client.Client, *token.SessionToken, error) {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+	if len(p.clientPacks) == 1 {
+		cp := p.clientPacks[0]
+		if cp.healthy {
+			return cp.client, cp.sessionToken, nil
+		}
+		return nil, nil, errors.New("no healthy client")
+	}
+	attempts := 3 * len(p.clientPacks)
+	for k := 0; k < attempts; k++ {
+		i := p.sampler.Next()
+		if cp := p.clientPacks[i]; cp.healthy {
+			return cp.client, cp.sessionToken, nil
+		}
+	}
+	return nil, nil, errors.New("no healthy client")
+}

pkg/pool/sampler.go

@@ -0,0 +1,81 @@
+package pool
+
+import "math/rand"
+
+// Sampler implements weighted random number generation using Vose's Alias
+// Method (https://www.keithschwarz.com/darts-dice-coins/).
+type Sampler struct {
+	randomGenerator *rand.Rand
+	probabilities   []float64
+	alias           []int
+}
+
+// NewSampler creates new Sampler with a given set of probabilities using
+// given source of randomness. Created Sampler will produce numbers from
+// 0 to len(probabilities).
+func NewSampler(probabilities []float64, source rand.Source) *Sampler {
+	sampler := &Sampler{}
+	var (
+		small workList
+		large workList
+	)
+	n := len(probabilities)
+	sampler.randomGenerator = rand.New(source)
+	sampler.probabilities = make([]float64, n)
+	sampler.alias = make([]int, n)
+	// Compute scaled probabilities.
+	p := make([]float64, n)
+	for i := 0; i < n; i++ {
+		p[i] = probabilities[i] * float64(n)
+	}
+	for i, pi := range p {
+		if pi < 1 {
+			small.add(i)
+		} else {
+			large.add(i)
+		}
+	}
+	for len(small) > 0 && len(large) > 0 {
+		l, g := small.remove(), large.remove()
+		sampler.probabilities[l] = p[l]
+		sampler.alias[l] = g
+		p[g] = p[g] + p[l] - 1
+		if p[g] < 1 {
+			small.add(g)
+		} else {
+			large.add(g)
+		}
+	}
+	for len(large) > 0 {
+		g := large.remove()
+		sampler.probabilities[g] = 1
+	}
+	for len(small) > 0 {
+		l := small.remove()
+		sampler.probabilities[l] = 1
+	}
+	return sampler
+}
+
+// Next returns the next (not so) random number from Sampler.
+func (g *Sampler) Next() int {
+	n := len(g.alias)
+	i := g.randomGenerator.Intn(n)
+	if g.randomGenerator.Float64() < g.probabilities[i] {
+		return i
+	}
+	return g.alias[i]
+}
+
+type workList []int
+
+func (wl *workList) add(e int) {
+	*wl = append(*wl, e)
+}
+
+func (wl *workList) remove() int {
+	l := len(*wl) - 1
+	n := (*wl)[l]
+	*wl = (*wl)[:l]
+	return n
+}