Rules: add e2e test

Signed-off-by: Jimmie Han <hanjinming@outlook.com>

test/e2e/rule_test.go

@@ -98,6 +98,21 @@ groups:
     annotations:
       summary: "I always complain and I have been loaded via sighup signal."
 `
+	testAlertRuleWithLimit = `
+groups:
+- name: example_with_limit
+  interval: 1s
+  limit: 1
+  partial_response_strategy: "WARN"
+  rules:
+  - alert: TestAlert_WithLimit
+    expr: some_metric
+    labels:
+      severity: page
+    annotations:
+      summary: "with limit"
+`
+
 	testRuleRecordAbsentMetric = `
 groups:
 - name: example_record_rules

test/e2e/rules_api_test.go

@@ -42,7 +42,8 @@ func TestRulesAPI_Fanout(t *testing.T) {
 	thanosRulesSubDir := filepath.Join("thanos-rules")
 	testutil.Ok(t, os.MkdirAll(filepath.Join(e.SharedDir(), thanosRulesSubDir), os.ModePerm))
 	createRuleFiles(t, filepath.Join(e.SharedDir(), thanosRulesSubDir))
-
+	// We create a rule group with limit.
+	createRuleFile(t, filepath.Join(e.SharedDir(), thanosRulesSubDir, "rules-with-limit.yaml"), testAlertRuleWithLimit)
 	// 2x Prometheus.
 	prom1, sidecar1, err := e2ethanos.NewPrometheusWithSidecar(
 		e,
@@ -135,6 +136,21 @@ func TestRulesAPI_Fanout(t *testing.T) {
 				}),
 			},
 		},
+		{
+			Name:  "example_with_limit",
+			File:  "/shared/thanos-rules/rules-with-limit.yaml",
+			Limit: 1,
+			Rules: []*rulespb.Rule{
+				rulespb.NewAlertingRule(&rulespb.Alert{
+					Name:  "TestAlert_WithLimit",
+					State: rulespb.AlertState_INACTIVE,
+					Query: "some_metric",
+					Labels: labelpb.ZLabelSet{Labels: []labelpb.ZLabel{
+						{Name: "severity", Value: "page"},
+					}},
+				}),
+			},
+		},
 	})
 }