fix: Fix loki ruler generator url left parameter url encoding (#15601)

The generate URL `left` parameter is not URL encoded. The double quotes in str variable around "queries" break hyperlinking.

pkg/ruler/base/ruler.go

@@ -407,9 +407,9 @@ func grafanaLinkForExpression(expr, datasourceUID string) string {
 	}
 
 	marshaledExpression, _ := json.Marshal(exprStruct)
-	escapedExpression := url.QueryEscape(string(marshaledExpression))
-	str := `/explore?left={"queries":[%s]}`
-	return fmt.Sprintf(str, escapedExpression)
+	params := url.Values{}
+	params.Set("left", fmt.Sprintf(`{"queries":[%s]}`, marshaledExpression))
+	return `/explore?` + params.Encode()
 }
 
 // SendAlerts implements a rules.NotifyFunc for a Notifier.

pkg/ruler/base/ruler_test.go

@@ -1733,7 +1733,7 @@ func TestSendAlerts(t *testing.T) {
 					Annotations:  []labels.Label{{Name: "a2", Value: "v2"}},
 					StartsAt:     time.Unix(2, 0),
 					EndsAt:       time.Unix(3, 0),
-					GeneratorURL: fmt.Sprintf("http://localhost:8080/explore?left={\"queries\":[%s]}", escapedExpression),
+					GeneratorURL: fmt.Sprintf("http://localhost:8080/explore?left=%%7B%%22queries%%22%%3A%%5B%s%%5D%%7D", escapedExpression),
 				},
 			},
 		},
@@ -1753,7 +1753,7 @@ func TestSendAlerts(t *testing.T) {
 					Annotations:  []labels.Label{{Name: "a2", Value: "v2"}},
 					StartsAt:     time.Unix(2, 0),
 					EndsAt:       time.Unix(4, 0),
-					GeneratorURL: fmt.Sprintf("http://localhost:8080/explore?left={\"queries\":[%s]}", escapedExpression),
+					GeneratorURL: fmt.Sprintf("http://localhost:8080/explore?left=%%7B%%22queries%%22%%3A%%5B%s%%5D%%7D", escapedExpression),
 				},
 			},
 		},