node: support reloading node attributes with SIGHUP

Add a new function `cfg.reloadNodeAttributes` that updates the list of node
attributes.
Add docs.

Closes #1870.

Signed-off-by: Andrey Butusov <andrey@nspcc.io>

CHANGELOG.md

@@ -19,6 +19,7 @@ attribute, which is used for container domain name in NNS contracts (#2954)
 - Docs files for cli commands to the `docs/cli-commands` folder (#2983)
 - `logger.encoding` config option (#2999)
 - Reloading morph endpoints with SIGHUP (#2998)
+- Reloading node attributes with SIGHUP (#3005)
 
 ### Fixed
 - Do not search for tombstones when handling their expiration, use local indexes instead (#2929)

cmd/neofs-node/config.go

@@ -876,6 +876,14 @@ func (c *cfg) configWatcher(ctx context.Context) {
 
 			c.cli.Reload(client.WithEndpoints(c.morph.endpoints))
 
+			// Node
+
+			err = c.reloadNodeAttributes()
+			if err != nil {
+				c.log.Error("invalid node attributes configuration", zap.Error(err))
+				continue
+			}
+
 			c.log.Info("configuration has been reloaded successfully")
 		case <-ctx.Done():
 			return

cmd/neofs-node/netmap.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"sync/atomic"
 
+	netmapV2 "github.com/nspcc-dev/neofs-api-go/v2/netmap"
 	netmapGRPC "github.com/nspcc-dev/neofs-api-go/v2/netmap/grpc"
 	"github.com/nspcc-dev/neofs-node/pkg/core/netmap"
 	"github.com/nspcc-dev/neofs-node/pkg/metrics"
@@ -445,3 +446,31 @@ func (n *netInfo) Dump(ver version.Version) (*netmapSDK.NetworkInfo, error) {
 
 	return &ni, nil
 }
+
+func (c *cfg) reloadNodeAttributes() error {
+	epoch, ni, err := getNetworkState(c)
+	if err != nil {
+		return err
+	}
+
+	var ni2 netmapV2.NodeInfo
+	c.cfgNodeInfo.localInfo.WriteToV2(&ni2)
+
+	ni2.SetAttributes([]netmapV2.Attribute{})
+
+	err = c.cfgNodeInfo.localInfo.ReadFromV2(ni2)
+	if err != nil {
+		return err
+	}
+
+	err = writeSystemAttributes(c)
+	if err != nil {
+		return err
+	}
+
+	parseAttributes(c)
+
+	updateLocalState(c, epoch, ni)
+
+	return nil
+}

docs/sighup.md

@@ -38,3 +38,9 @@ comparing paths from `shard.blobstor` section. After this we have 3 sets:
 | Changed section | Actions                                                                                                                                                                                                 |
 |-----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `endpoints`     | Updates N3 endpoints.<br/>If new `endpoints` do not contain the endpoint client is connected to, it will reconnect to another endpoint from the new list. Node service can be interrupted in this case. |
+
+### Node
+
+| Changed section | Actions                  |
+|-----------------|--------------------------|
+| `attribute_*`   | Updates node attributes. |