[#1609] config: Allow to prioritize N3 endpoints

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

cmd/neofs-node/config/morph/config.go

@@ -2,9 +2,11 @@ package morphconfig
 
 import (
 	"fmt"
+	"strconv"
 	"time"
 
 	"github.com/nspcc-dev/neofs-node/cmd/neofs-node/config"
+	"github.com/nspcc-dev/neofs-node/pkg/morph/client"
 )
 
 const (
@@ -28,13 +30,27 @@ const (
 // from "morph" section.
 //
 // Throws panic if list is empty.
-func RPCEndpoint(c *config.Config) []string {
-	v := config.StringSliceSafe(c.Sub(subsection), "rpc_endpoint")
-	if len(v) == 0 {
-		panic(fmt.Errorf("no morph chain RPC endpoints, see `morph.rpc_endpoint` section"))
+func RPCEndpoint(c *config.Config) []client.Endpoint {
+	var es []client.Endpoint
+
+	sub := c.Sub(subsection).Sub("rpc_endpoint")
+	for i := 0; ; i++ {
+		s := sub.Sub(strconv.FormatInt(int64(i), 10))
+		addr := config.StringSafe(s, "address")
+		if addr == "" {
+			break
+		}
+
+		es = append(es, client.Endpoint{
+			Address:  addr,
+			Priority: int(config.IntSafe(s, "priority")),
+		})
 	}
 
-	return v
+	if len(es) == 0 {
+		panic(fmt.Errorf("no morph chain RPC endpoints, see `morph.rpc_endpoint` section"))
+	}
+	return es
 }
 
 // DialTimeout returns the value of "dial_timeout" config parameter

cmd/neofs-node/config/morph/config_test.go

@@ -7,6 +7,7 @@ import (
 	"github.com/nspcc-dev/neofs-node/cmd/neofs-node/config"
 	morphconfig "github.com/nspcc-dev/neofs-node/cmd/neofs-node/config/morph"
 	configtest "github.com/nspcc-dev/neofs-node/cmd/neofs-node/config/test"
+	"github.com/nspcc-dev/neofs-node/pkg/morph/client"
 	"github.com/stretchr/testify/require"
 )
 
@@ -22,9 +23,9 @@ func TestMorphSection(t *testing.T) {
 	const path = "../../../../config/example/node"
 
 	var (
-		rpcs = []string{
-			"wss://rpc1.morph.fs.neo.org:40341/ws",
-			"wss://rpc2.morph.fs.neo.org:40341/ws",
+		rpcs = []client.Endpoint{
+			{"wss://rpc1.morph.fs.neo.org:40341/ws", 2},
+			{"wss://rpc2.morph.fs.neo.org:40341/ws", 1},
 		}
 	)
 

cmd/neofs-node/morph.go

@@ -35,18 +35,17 @@ func initMorphComponents(c *cfg) {
 	var err error
 
 	addresses := morphconfig.RPCEndpoint(c.appCfg)
-	if len(addresses) == 0 {
-		fatalOnErr(errors.New("missing Neo RPC endpoints"))
-	}
 
+	// Morph client stable-sorts endpoints by priority. Shuffle here to randomize
+	// order of endpoints with the same priority.
 	rand.Shuffle(len(addresses), func(i, j int) {
 		addresses[i], addresses[j] = addresses[j], addresses[i]
 	})
 
-	cli, err := client.New(c.key, addresses[0],
+	cli, err := client.New(c.key,
 		client.WithDialTimeout(morphconfig.DialTimeout(c.appCfg)),
 		client.WithLogger(c.log),
-		client.WithExtraEndpoints(addresses[1:]),
+		client.WithEndpoints(addresses...),
 		client.WithConnLostCallback(func() {
 			c.internalErr <- errors.New("morph connection has been lost")
 		}),