From 98ac3036fe17427f4361bcb9315b8dc8eb3c0b3f Mon Sep 17 00:00:00 2001
From: Piotr Kazmierczak <470696+pkazmierczak@users.noreply.github.com>
Date: Mon, 27 Nov 2023 08:33:08 +0000
Subject: [PATCH] backport of commit 742651f2f715af69dda77b8ffb3af3d114e25ac2

---
 .changelog/19172.txt            |  3 +++
 command/agent/alloc_endpoint.go | 10 ++++++++++
 2 files changed, 13 insertions(+)
 create mode 100644 .changelog/19172.txt

diff --git a/.changelog/19172.txt b/.changelog/19172.txt
new file mode 100644
index 00000000000..15443ba4b67
--- /dev/null
+++ b/.changelog/19172.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+agent: Correct websocket status code handling
+```
diff --git a/command/agent/alloc_endpoint.go b/command/agent/alloc_endpoint.go
index e17369a4c80..d63f5777e93 100644
--- a/command/agent/alloc_endpoint.go
+++ b/command/agent/alloc_endpoint.go
@@ -7,6 +7,7 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"slices"
 	"strconv"
 	"strings"
 
@@ -668,6 +669,15 @@ func isClosedError(err error) bool {
 		return false
 	}
 
+	// check if the websocket "error" is one of the benign "close" status codes
+	if codedErr, ok := err.(HTTPCodedError); ok {
+		return slices.ContainsFunc([]string{
+			"close 1000", // CLOSE_NORMAL
+			"close 1001", // CLOSE_GOING_AWAY
+			"close 1005", // CLOSED_NO_STATUS
+		}, func(s string) bool { return strings.Contains(codedErr.Error(), s) })
+	}
+
 	return err == io.EOF ||
 		err == io.ErrClosedPipe ||
 		strings.Contains(err.Error(), "closed") ||