[v11.0.x] Alerting: Fix rule storage to filter by group names using case-sensitive comparison (#89063)

Alerting: Fix rule storage to filter by group names using case-sensitive comparison (#88992)

* add test for the bug
* remove unused struct
* update db store to post process filters by group using go-lang's case-sensitive string comparison

--------

Co-authored-by: Alexander Weaver <weaver.alex.d@gmail.com>
# Conflicts:
#	pkg/services/ngalert/store/alert_rule.go
#	pkg/services/ngalert/store/alert_rule_test.go

pkg/services/ngalert/models/alert_rule.go

@@ -630,18 +630,6 @@ type ListNamespaceAlertRulesQuery struct {
 	NamespaceUID string
 }
 
-// ListOrgRuleGroupsQuery is the query for listing unique rule groups
-// for an organization
-type ListOrgRuleGroupsQuery struct {
-	OrgID         int64
-	NamespaceUIDs []string
-
-	// DashboardUID and PanelID are optional and allow filtering rules
-	// to return just those for a dashboard and panel.
-	DashboardUID string
-	PanelID      int64
-}
-
 type UpdateRule struct {
 	Existing *AlertRule
 	New      AlertRule

pkg/services/ngalert/store/alert_rule.go

@@ -113,7 +113,23 @@ func (st DBstore) GetAlertRulesGroupByRuleUID(ctx context.Context, query *ngmode
 		if err != nil {
 			return err
 		}
-		result = rules
+		// MySQL by default compares strings without case-sensitivity, make sure we keep the case-sensitive comparison.
+		var groupKey ngmodels.AlertRuleGroupKey
+		// find the rule, which group we fetch
+		for _, rule := range rules {
+			if rule.UID == query.UID {
+				groupKey = rule.GetGroupKey()
+				break
+			}
+		}
+		result = make([]*ngmodels.AlertRule, 0, len(rules))
+		// MySQL (and potentially other databases) can use case-insensitive comparison.
+		// This code makes sure we return groups that only exactly match the filter.
+		for _, rule := range rules {
+			if rule.GetGroupKey() == groupKey {
+				result = append(result, rule)
+			}
+		}
 		return nil
 	})
 	return result, err
@@ -407,6 +423,11 @@ func (st DBstore) ListAlertRules(ctx context.Context, query *ngmodels.ListAlertR
 					continue
 				}
 			}
+			// MySQL (and potentially other databases) can use case-insensitive comparison.
+			// This code makes sure we return groups that only exactly match the filter.
+			if query.RuleGroup != "" && query.RuleGroup != rule.RuleGroup {
+				continue
+			}
 			alertRules = append(alertRules, rule)
 		}
 
@@ -522,8 +543,13 @@ func (st DBstore) GetAlertRulesForScheduling(ctx context.Context, query *ngmodel
 			alertRulesSql.NotIn("org_id", disabledOrgs)
 		}
 
+		var groupsMap map[string]struct{}
 		if len(query.RuleGroups) > 0 {
 			alertRulesSql.In("rule_group", query.RuleGroups)
+			groupsMap = make(map[string]struct{}, len(query.RuleGroups))
+			for _, group := range query.RuleGroups {
+				groupsMap[group] = struct{}{}
+			}
 		}
 
 		rule := new(ngmodels.AlertRule)
@@ -544,6 +570,13 @@ func (st DBstore) GetAlertRulesForScheduling(ctx context.Context, query *ngmodel
 				st.Logger.Error("Invalid rule found in DB store, ignoring it", "func", "GetAlertRulesForScheduling", "error", err)
 				continue
 			}
+			// MySQL (and potentially other databases) uses case-insensitive comparison.
+			// This code makes sure we return groups that only exactly match the filter
+			if groupsMap != nil {
+				if _, ok := groupsMap[rule.RuleGroup]; !ok { // compare groups using case-sensitive logic.
+					continue
+				}
+			}
 			if st.FeatureToggles.IsEnabled(ctx, featuremgmt.FlagAlertingQueryOptimization) {
 				if optimizations, err := OptimizeAlertQueries(rule.Data); err != nil {
 					st.Logger.Error("Could not migrate rule from range to instant query", "rule", rule.UID, "err", err)

pkg/services/ngalert/store/alert_rule_test.go

@@ -392,6 +392,11 @@ func TestIntegration_GetAlertRulesForScheduling(t *testing.T) {
 			ruleGroups: []string{rule1.RuleGroup},
 			rules:      []string{rule1.Title},
 		},
+		{
+			name:       "with a rule group filter, should be case sensitive",
+			ruleGroups: []string{strings.ToUpper(rule1.RuleGroup)},
+			rules:      []string{},
+		},
 		{
 			name:         "with a filter on orgs, it returns rules that do not belong to that org",
 			rules:        []string{rule1.Title},