From 19aff22bc75ff36495f43f2244c04fa3760c85cc Mon Sep 17 00:00:00 2001
From: Andrey Butusov <andrey@nspcc.io>
Date: Tue, 29 Oct 2024 17:52:58 +0300
Subject: [PATCH] morph: support reloading morph endpoints with SIGHUP

Add a new function `Client.Reload` that passes the `WithEndpoints` option and
updates the `Client` endpoints.
Add docs.

Closes #1871.

Signed-off-by: Andrey Butusov <andrey@nspcc.io>
---
 CHANGELOG.md                    |  1 +
 cmd/neofs-node/config.go        |  4 ++++
 docs/sighup.md                  |  6 ++++++
 pkg/morph/client/constructor.go |  4 +++-
 pkg/morph/client/multi.go       |  3 +++
 pkg/morph/client/reload.go      | 15 +++++++++++++++
 6 files changed, 32 insertions(+), 1 deletion(-)
 create mode 100644 pkg/morph/client/reload.go

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1aef08c7f4..3215b51138 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ attribute, which is used for container domain name in NNS contracts (#2954)
 - `neofs-cli control object revive` command (#2968)
 - `--disable-auto-gen-tag` flag for gendoc command (#2983)
 - Docs files for cli commands to the `docs/cli-commands` folder (#2983)
+- Reloading morph endpoints with SIGHUP (#2998)
 
 ### Fixed
 - Do not search for tombstones when handling their expiration, use local indexes instead (#2929)
diff --git a/cmd/neofs-node/config.go b/cmd/neofs-node/config.go
index 76d762ad92..56beef3bd2 100644
--- a/cmd/neofs-node/config.go
+++ b/cmd/neofs-node/config.go
@@ -870,6 +870,10 @@ func (c *cfg) configWatcher(ctx context.Context) {
 				continue
 			}
 
+			// Morph
+
+			c.cli.Reload(client.WithEndpoints(c.morph.endpoints))
+
 			c.log.Info("configuration has been reloaded successfully")
 		case <-ctx.Done():
 			return
diff --git a/docs/sighup.md b/docs/sighup.md
index 9b32a0761a..4a879d7ddc 100644
--- a/docs/sighup.md
+++ b/docs/sighup.md
@@ -32,3 +32,9 @@ comparing paths from `shard.blobstor` section. After this we have 3 sets:
 | Changed section | Actions                                                                                                              |
 |-----------------|----------------------------------------------------------------------------------------------------------------------|
 | `path`          | If `path` is different, metabase is closed and opened with a new path. All other configuration will also be updated. |
+
+### Morph
+
+| Changed section | Actions              |
+|-----------------|----------------------|
+| `endpoints`     | Update N3 endpoints. |
diff --git a/pkg/morph/client/constructor.go b/pkg/morph/client/constructor.go
index c852b0f941..dd827345e5 100644
--- a/pkg/morph/client/constructor.go
+++ b/pkg/morph/client/constructor.go
@@ -40,7 +40,8 @@ type cfg struct {
 	autoSidechainScope bool
 	signer             *transaction.Signer
 
-	endpoints []string
+	endpoints     []string
+	endpointsLock *sync.RWMutex
 
 	singleCli *rpcclient.WSClient // neo-go client for single client mode
 
@@ -63,6 +64,7 @@ func defaultConfig() *cfg {
 		signer: &transaction.Signer{
 			Scopes: transaction.CalledByEntry,
 		},
+		endpointsLock:       &sync.RWMutex{},
 		reconnectionDelay:   5 * time.Second,
 		reconnectionRetries: 5,
 	}
diff --git a/pkg/morph/client/multi.go b/pkg/morph/client/multi.go
index 160e71534c..1de456ef63 100644
--- a/pkg/morph/client/multi.go
+++ b/pkg/morph/client/multi.go
@@ -33,6 +33,9 @@ func (c *Client) switchRPC() *connection {
 }
 
 func (c *Client) connEndpoints() *connection {
+	c.cfg.endpointsLock.RLock()
+	defer c.cfg.endpointsLock.RUnlock()
+
 	// Iterate endpoints.
 	for _, e := range c.cfg.endpoints {
 		conn, err := c.newConnection(e)
diff --git a/pkg/morph/client/reload.go b/pkg/morph/client/reload.go
new file mode 100644
index 0000000000..7288993c09
--- /dev/null
+++ b/pkg/morph/client/reload.go
@@ -0,0 +1,15 @@
+package client
+
+// Reload allows runtime reconfiguration for WithEndpoints parameter.
+func (c *Client) Reload(opts ...Option) {
+	cfg := new(cfg)
+	for _, o := range opts {
+		o(cfg)
+	}
+
+	c.cfg.endpointsLock.Lock()
+
+	c.cfg.endpoints = cfg.endpoints
+
+	c.cfg.endpointsLock.Unlock()
+}