[#1183] node: Add NATS client

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

go.mod

@@ -8,10 +8,12 @@ require (
 	github.com/google/go-github/v39 v39.2.0
 	github.com/google/uuid v1.2.0
 	github.com/hashicorp/golang-lru v0.5.4
-	github.com/klauspost/compress v1.13.1
+	github.com/klauspost/compress v1.13.4
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/mr-tron/base58 v1.2.0
 	github.com/multiformats/go-multiaddr v0.4.0
+	github.com/nats-io/nats-server/v2 v2.7.2 // indirect
+	github.com/nats-io/nats.go v1.13.1-0.20220121202836-972a071d373d
 	github.com/nspcc-dev/hrw v1.0.9
 	github.com/nspcc-dev/neo-go v0.98.0
 	github.com/nspcc-dev/neofs-api-go/v2 v2.12.0

go.sum

@@ -287,8 +287,8 @@ github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvW
 github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23/go.mod h1:J+Gs4SYgM6CZQHDETBtE9HaSEkGmuNXF86RwHhHUvq4=
-github.com/klauspost/compress v1.13.1 h1:wXr2uRxZTJXHLly6qhJabee5JqIhTRoLBhDOA74hDEQ=
+github.com/klauspost/compress v1.13.4 h1:0zhec2I8zGnjWcKyLl6i3gPqKANCCn5e9xmviEEeX6s=
-github.com/klauspost/compress v1.13.1/go.mod h1:8dP1Hq4DHOhN9w426knH3Rhby4rFm6D8eO+e+Dq5Gzg=
+github.com/klauspost/compress v1.13.4/go.mod h1:8dP1Hq4DHOhN9w426knH3Rhby4rFm6D8eO+e+Dq5Gzg=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/fs v0.1.0/go.mod h1:FFnZGqtBN9Gxj7eW1uZ42v5BccTP0vu6NEaFoC2HwRg=
@@ -317,6 +317,8 @@ github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5
 github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
 github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1 h1:lYpkrQH5ajf0OXOcUbGjvZxxijuBwbbmlSxLiuofa+g=
 github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1/go.mod h1:pD8RvIylQ358TN4wwqatJ8rNavkEINozVn9DtGI3dfQ=
+github.com/minio/highwayhash v1.0.1 h1:dZ6IIu8Z14VlC0VpfKofAhCy74wu/Qb5gcn52yWoz/0=
+github.com/minio/highwayhash v1.0.1/go.mod h1:BQskDq+xkJ12lmlUUi7U0M5Swg3EWR+dLTk+kldvVxY=
 github.com/minio/sha256-simd v0.1.1-0.20190913151208-6de447530771 h1:MHkK1uRtFbVqvAgvWxafZe54+5uBxLluGylDiKgdhwo=
 github.com/minio/sha256-simd v0.1.1-0.20190913151208-6de447530771/go.mod h1:B5e1o+1/KgNmWrSQK08Y6Z1Vb5pwIktudl0J58iy0KM=
 github.com/mitchellh/cli v1.0.0/go.mod h1:hNIlj7HEI86fIcpObd7a0FcrxTWetlwJDGcceTlRvqc=
@@ -355,6 +357,16 @@ github.com/multiformats/go-varint v0.0.6 h1:gk85QWKxh3TazbLxED/NlDVv8+q+ReFJk7Y2
 github.com/multiformats/go-varint v0.0.6/go.mod h1:3Ls8CIEsrijN6+B7PbrXRPxHRPuXSrVKRY101jdMZYE=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
+github.com/nats-io/jwt/v2 v2.2.1-0.20220113022732-58e87895b296 h1:vU9tpM3apjYlLLeY23zRWJ9Zktr5jp+mloR942LEOpY=
+github.com/nats-io/jwt/v2 v2.2.1-0.20220113022732-58e87895b296/go.mod h1:0tqz9Hlu6bCBFLWAASKhE5vUA4c24L9KPUUgvwumE/k=
+github.com/nats-io/nats-server/v2 v2.7.2 h1:+LEN8m0+jdCkiGc884WnDuxR+qj80/5arj+szKuRpRI=
+github.com/nats-io/nats-server/v2 v2.7.2/go.mod h1:tckmrt0M6bVaDT3kmh9UrIq/CBOBBse+TpXQi5ldaa8=
+github.com/nats-io/nats.go v1.13.1-0.20220121202836-972a071d373d h1:GRSmEJutHkdoxKsRypP575IIdoXe7Bm6yHQF6GcDBnA=
+github.com/nats-io/nats.go v1.13.1-0.20220121202836-972a071d373d/go.mod h1:BPko4oXsySz4aSWeFgOHLZs3G4Jq4ZAyE6/zMCxRT6w=
+github.com/nats-io/nkeys v0.3.0 h1:cgM5tL53EvYRU+2YLXIK0G2mJtK12Ft9oeooSZMA2G8=
+github.com/nats-io/nkeys v0.3.0/go.mod h1:gvUNGjVcM2IPr5rCsRsC6Wb3Hr2CQAm08dsxtV6A5y4=
+github.com/nats-io/nuid v1.0.1 h1:5iA8DT8V7q8WK2EScv2padNa/rTESc1KdnPw4TC2paw=
+github.com/nats-io/nuid v1.0.1/go.mod h1:19wcPz3Ph3q0Jbyiqsd0kePYG7A95tJPxeL+1OSON2c=
 github.com/nspcc-dev/dbft v0.0.0-20191205084618-dacb1a30c254/go.mod h1:w1Ln2aT+dBlPhLnuZhBV+DfPEdS2CHWWLp5JTScY3bw=
 github.com/nspcc-dev/dbft v0.0.0-20191209120240-0d6b7568d9ae/go.mod h1:3FjXOoHmA51EGfb5GS/HOv7VdmngNRTssSeQ729dvGY=
 github.com/nspcc-dev/dbft v0.0.0-20200117124306-478e5cfbf03a/go.mod h1:/YFK+XOxxg0Bfm6P92lY5eDSLYfp06XOdL8KAVgXjVk=
@@ -555,9 +567,11 @@ golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8U
 golang.org/x/crypto v0.0.0-20200115085410-6d4e4cb37c7d/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200510223506-06a226fb4e37/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20210314154223-e6e6c4f2bb5b/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
 golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
-golang.org/x/crypto v0.0.0-20210817164053-32db794688a5 h1:HWj/xjIHfjYU5nVXpTM0s39J9CbLn7Cc5a7IC5rwsMQ=
 golang.org/x/crypto v0.0.0-20210817164053-32db794688a5/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/crypto v0.0.0-20220112180741-5e0467b6c7ce h1:Roh6XWxHFKrPgC/EQhVubSAGQ6Ozk6IdxHSzt1mR0EI=
+golang.org/x/crypto v0.0.0-20220112180741-5e0467b6c7ce/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190510132918-efd6b22b2522/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
@@ -636,8 +650,9 @@ golang.org/x/net v0.0.0-20201209123823-ac852fbbde11/go.mod h1:m0MpNAwzfU5UDzcl9v
 golang.org/x/net v0.0.0-20210119194325-5f4716e94777/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4/go.mod h1:RBQZq4jEuRlivfhVLdyRGr576XBO4/greRjx4P4O3yc=
-golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 h1:4nGaVu0QrbjT/AK2PRLuQfQuh6DJve+pELhqTdAj3x0=
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
+golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2 h1:CIJ76btIcR3eFI5EgSo6k1qKw9KJexJuRLI9G7Hp5wE=
+golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -669,6 +684,7 @@ golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20181026203630-95b1ffbd15a5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181107165924-66b7b1311ac8/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190130150945-aca44879d564/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190204203706-41f3e6584952/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -722,9 +738,11 @@ golang.org/x/sys v0.0.0-20210315160823-c6e025ad8005/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210403161142-5e06dd20ab57/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210603081109-ebe580a85c40/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220111092808-5a964db01320/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220114195835-da31bd327af9 h1:XfKQ4OlFl8okEOr5UvAqFRVj8pY/4yfcXrddB8qAbU0=
 golang.org/x/sys v0.0.0-20220114195835-da31bd327af9/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
@@ -742,6 +760,8 @@ golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
+golang.org/x/time v0.0.0-20211116232009-f0f3c7e86c11 h1:GZokNIeuVkl3aZHJchRrr13WCsols02MLUcz1U9is6M=
+golang.org/x/time v0.0.0-20211116232009-f0f3c7e86c11/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20180318012157-96caea41033d/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

pkg/services/notificator/nats/options.go

@@ -0,0 +1,38 @@
+package nats
+
+import (
+	"time"
+
+	"github.com/nats-io/nats.go"
+	"go.uber.org/zap"
+)
+
+func WithClientCert(certPath, keyPath string) Option {
+	return func(o *opts) {
+		o.nOpts = append(o.nOpts, nats.ClientCert(certPath, keyPath))
+	}
+}
+
+func WithRootCA(paths ...string) Option {
+	return func(o *opts) {
+		o.nOpts = append(o.nOpts, nats.RootCAs(paths...))
+	}
+}
+
+func WithTimeout(timeout time.Duration) Option {
+	return func(o *opts) {
+		o.nOpts = append(o.nOpts, nats.Timeout(timeout))
+	}
+}
+
+func WithConnectionName(name string) Option {
+	return func(o *opts) {
+		o.nOpts = append(o.nOpts, nats.Name(name))
+	}
+}
+
+func WithLogger(logger *zap.Logger) Option {
+	return func(o *opts) {
+		o.logger = logger
+	}
+}

pkg/services/notificator/nats/service.go

@@ -0,0 +1,129 @@
+package nats
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sync"
+
+	"github.com/nats-io/nats.go"
+	addressSDK "github.com/nspcc-dev/neofs-sdk-go/object/address"
+	"go.uber.org/zap"
+)
+
+// Writer is a NATS object notification writer.
+// It handles NATS JetStream connections and allows
+// sending string representation of the address to
+// the NATS server.
+//
+// For correct operation must be created via New function.
+// new(Writer) or Writer{} construction leads to undefined
+// behaviour and is not safe.
+type Writer struct {
+	log *zap.Logger
+	js  nats.JetStreamContext
+	nc  *nats.Conn
+
+	m              *sync.RWMutex
+	createdStreams map[string]struct{}
+}
+
+type opts struct {
+	logger *zap.Logger
+	nOpts  []nats.Option
+}
+
+type Option func(*opts)
+
+var errConnIsClosed = errors.New("connection to the server is closed")
+
+// Notify sends object address's string representation to the provided topic.
+// Uses first 4 bytes of object ID as a message ID to support 'exactly once message'
+// delivery.
+//
+// Returns error only if:
+// 1. underlying connection was closed and has not established again;
+// 2. NATS server could not respond that is has saved the message.
+func (n *Writer) Notify(topic string, address *addressSDK.Address) error {
+	if !n.nc.IsConnected() {
+		return errConnIsClosed
+	}
+
+	// use first 4 byte of the encoded string as
+	// message ID for the exactly-once delivery
+	messageID := address.ObjectID().String()[:4]
+
+	// check if the stream was previously created
+	n.m.RLock()
+	_, created := n.createdStreams[topic]
+	n.m.RUnlock()
+
+	if !created {
+		_, err := n.js.AddStream(&nats.StreamConfig{
+			Name: topic,
+		})
+		if err != nil {
+			return fmt.Errorf("could not add stream: %w", err)
+		}
+
+		n.m.Lock()
+		n.createdStreams[topic] = struct{}{}
+		n.m.Unlock()
+	}
+
+	_, err := n.js.Publish(topic, []byte(address.String()), nats.MsgId(messageID))
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// New creates and inits new Writer.
+// Connection is closed when passed context is done.
+//
+// Returns error only if fails to open connection to a NATS server
+// with provided configuration.
+func New(ctx context.Context, endpoint string, oo ...Option) (*Writer, error) {
+	opts := &opts{
+		logger: zap.L(),
+		nOpts:  make([]nats.Option, 0, len(oo)+3),
+	}
+
+	for _, o := range oo {
+		o(opts)
+	}
+
+	opts.nOpts = append(opts.nOpts,
+		nats.NoCallbacksAfterClientClose(), // do not call callbacks when it was planned writer stop
+		nats.DisconnectErrHandler(func(conn *nats.Conn, err error) {
+			opts.logger.Error("nats: connection was lost", zap.Error(err))
+		}),
+		nats.ReconnectHandler(func(conn *nats.Conn) {
+			opts.logger.Warn("nats: reconnected to the server")
+		}),
+	)
+
+	nc, err := nats.Connect(endpoint, opts.nOpts...)
+	if err != nil {
+		return nil, fmt.Errorf("could not connect to server: %w", err)
+	}
+
+	// usage w/o options is error-free
+	js, _ := nc.JetStream()
+
+	go func() {
+		<-ctx.Done()
+		opts.logger.Info("nats: closing connection as the context is done")
+
+		nc.Close()
+	}()
+
+	return &Writer{
+		js:             js,
+		nc:             nc,
+		log:            opts.logger,
+		m:              &sync.RWMutex{},
+		createdStreams: make(map[string]struct{}),
+	}, nil
+}