From 742196b6c4918d9d08b8349182b12471d9b223e1 Mon Sep 17 00:00:00 2001
From: Erlan Zholdubai uulu <erlan@engineer.com>
Date: Tue, 19 Mar 2024 10:37:43 -0700
Subject: [PATCH] add context cancellation check at get series result iteration
 (#13766)

* add context cancellation check at get series iteration
* add warnings and closer on error
* add test

---------

Signed-off-by: Erlan Zholdubai uulu <erlanz@amazon.com>
---
 web/api/v1/api.go      | 3 +++
 web/api/v1/api_test.go | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/web/api/v1/api.go b/web/api/v1/api.go
index b56026e45e..dc22365073 100644
--- a/web/api/v1/api.go
+++ b/web/api/v1/api.go
@@ -882,6 +882,9 @@ func (api *API) series(r *http.Request) (result apiFuncResult) {
 	warnings := set.Warnings()
 
 	for set.Next() {
+		if err := ctx.Err(); err != nil {
+			return apiFuncResult{nil, returnAPIError(err), warnings, closer}
+		}
 		metrics = append(metrics, set.At().Labels())
 
 		if len(metrics) >= limit {
diff --git a/web/api/v1/api_test.go b/web/api/v1/api_test.go
index 63a0225357..4158e544ef 100644
--- a/web/api/v1/api_test.go
+++ b/web/api/v1/api_test.go
@@ -3568,6 +3568,9 @@ func TestReturnAPIError(t *testing.T) {
 		}, {
 			err:      errors.New("exec error"),
 			expected: errorExec,
+		}, {
+			err:      context.Canceled,
+			expected: errorCanceled,
 		},
 	}