From 484836b9f90e320a530f15a5fe6459e0a31e91bb Mon Sep 17 00:00:00 2001
From: Dmitrii Stepanov <d.stepanov@yadro.com>
Date: Mon, 18 Dec 2023 17:55:24 +0300
Subject: [PATCH] [#878] node: Drain internal error's channel

This fixes shutdown panic:
1. Some morph connection gets error and passes it to internalErr channel.
2. Storage node starts to shutdow and closes internalErr channel.
3. Other morph connection gets error and tries to pass it to internalErr channel.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>
---
 cmd/frostfs-node/config.go |  1 -
 cmd/frostfs-node/main.go   | 14 ++++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/cmd/frostfs-node/config.go b/cmd/frostfs-node/config.go
index e36081ba6..62889e7aa 100644
--- a/cmd/frostfs-node/config.go
+++ b/cmd/frostfs-node/config.go
@@ -1325,5 +1325,4 @@ func (c *cfg) shutdown() {
 	for i := range c.closers {
 		c.closers[len(c.closers)-1-i].fn()
 	}
-	close(c.internalErr)
 }
diff --git a/cmd/frostfs-node/main.go b/cmd/frostfs-node/main.go
index 2fe3a0a25..f91a6decc 100644
--- a/cmd/frostfs-node/main.go
+++ b/cmd/frostfs-node/main.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"sync"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-node/config"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
@@ -155,9 +156,22 @@ func wait(c *cfg) {
 
 	<-c.done // graceful shutdown
 
+	drain := &sync.WaitGroup{}
+	drain.Add(1)
+	go func() {
+		defer drain.Done()
+		for err := range c.internalErr {
+			c.log.Warn(logs.FrostFSNodeInternalApplicationError,
+				zap.String("message", err.Error()))
+		}
+	}()
+
 	c.log.Debug(logs.FrostFSNodeWaitingForAllProcessesToStop)
 
 	c.wg.Wait()
+
+	close(c.internalErr)
+	drain.Wait()
 }
 
 func (c *cfg) onShutdown(f func()) {