Alerting: Rule version history API (#99041)

* implement store method to read rule versions

* implement request handler

* declare a new endpoint

* fix fake to return correct response

* add tests

* add integration tests

* rename history to versions

* apply diff from swagger CI step

Signed-off-by: Yuri Tseretyan <yuriy.tseretyan@grafana.com>

---------

Signed-off-by: Yuri Tseretyan <yuriy.tseretyan@grafana.com>

pkg/services/ngalert/store/alert_rule.go

@@ -118,6 +118,36 @@ func (st DBstore) GetAlertRuleByUID(ctx context.Context, query *ngmodels.GetAler
 	return result, err
 }
 
+func (st DBstore) GetAlertRuleVersions(ctx context.Context, key ngmodels.AlertRuleKey) ([]*ngmodels.AlertRule, error) {
+	alertRules := make([]*ngmodels.AlertRule, 0)
+	err := st.SQLStore.WithDbSession(ctx, func(sess *db.Session) error {
+		rows, err := sess.Table(new(alertRuleVersion)).Where("rule_org_id = ? AND rule_uid = ?", key.OrgID, key.UID).Desc("id").Rows(new(alertRuleVersion))
+		if err != nil {
+			return err
+		}
+		// Deserialize each rule separately in case any of them contain invalid JSON.
+		for rows.Next() {
+			rule := new(alertRuleVersion)
+			err = rows.Scan(rule)
+			if err != nil {
+				st.Logger.Error("Invalid rule version found in DB store, ignoring it", "func", "GetAlertRuleVersions", "error", err)
+				continue
+			}
+			converted, err := alertRuleToModelsAlertRule(alertRuleVersionToAlertRule(*rule), st.Logger)
+			if err != nil {
+				st.Logger.Error("Invalid rule found in DB store, cannot convert, ignoring it", "func", "GetAlertRuleVersions", "error", err, "version_id", rule.ID)
+				continue
+			}
+			alertRules = append(alertRules, &converted)
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return alertRules, nil
+}
+
 // GetRuleByID retrieves models.AlertRule by ID.
 // It returns models.ErrAlertRuleNotFound if no alert rule is found for the provided ID.
 func (st DBstore) GetRuleByID(ctx context.Context, query ngmodels.GetAlertRuleByIDQuery) (result *ngmodels.AlertRule, err error) {

pkg/services/ngalert/store/compat.go

@@ -204,3 +204,34 @@ func alertRuleToAlertRuleVersion(rule alertRule) alertRuleVersion {
 		Metadata:             rule.Metadata,
 	}
 }
+
+func alertRuleVersionToAlertRule(version alertRuleVersion) alertRule {
+	return alertRule{
+		ID:              version.ID,
+		OrgID:           version.RuleOrgID,
+		Title:           version.Title,
+		Condition:       version.Condition,
+		Data:            version.Data,
+		Updated:         version.Created,
+		UpdatedBy:       version.CreatedBy,
+		IntervalSeconds: version.IntervalSeconds,
+		Version:         version.Version,
+		UID:             version.RuleUID,
+		NamespaceUID:    version.RuleNamespaceUID,
+		// Versions do not store Dashboard\Panel as separate column.
+		// However, these fields are part of annotations and information in these fields is redundant
+		DashboardUID:         nil,
+		PanelID:              nil,
+		RuleGroup:            version.RuleGroup,
+		RuleGroupIndex:       version.RuleGroupIndex,
+		Record:               version.Record,
+		NoDataState:          version.NoDataState,
+		ExecErrState:         version.ExecErrState,
+		For:                  version.For,
+		Annotations:          version.Annotations,
+		Labels:               version.Labels,
+		IsPaused:             version.IsPaused,
+		NotificationSettings: version.NotificationSettings,
+		Metadata:             version.Metadata,
+	}
+}

pkg/services/ngalert/store/compat_test.go

@@ -43,3 +43,20 @@ func TestAlertRuleToModelsAlertRule(t *testing.T) {
 		require.Equal(t, ngmodels.ErrorErrState, converted.ExecErrState)
 	})
 }
+
+func TestAlertRuleVersionToAlertRule(t *testing.T) {
+	g := ngmodels.RuleGen
+
+	t.Run("make sure no data is lost between conversions", func(t *testing.T) {
+		for _, rule := range g.GenerateMany(100) {
+			// ignore fields
+			rule.DashboardUID = nil
+			rule.PanelID = nil
+
+			r, err := alertRuleFromModelsAlertRule(rule)
+			require.NoError(t, err)
+			r2 := alertRuleVersionToAlertRule(alertRuleToAlertRuleVersion(r))
+			require.Equal(t, r, r2)
+		}
+	})
+}