Alerting: Change rule migration to be based on feature flag (#33792)

makes it so the feature flag can be turned on off, and the migration will be cleared and rerun. All existing NG alert rules, configuration settings, etc are removed when disabling the feature flag.
for https://github.com/grafana/alerting-squad/issues/142

Co-authored-by: Sofia Papagiannaki <sofia@grafana.com>

pkg/services/sqlstore/migrations/migrations_test.go

@@ -5,6 +5,7 @@ import (
 
 	. "github.com/grafana/grafana/pkg/services/sqlstore/migrator"
 	"github.com/grafana/grafana/pkg/services/sqlstore/sqlutil"
+	"github.com/grafana/grafana/pkg/setting"
 	"github.com/stretchr/testify/require"
 	"xorm.io/xorm"
 )
@@ -23,7 +24,7 @@ func TestMigrations(t *testing.T) {
 	_, err = x.SQL(query).Get(&result)
 	require.Error(t, err)
 
-	mg := NewMigrator(x)
+	mg := NewMigrator(x, &setting.Cfg{})
 	AddMigrations(mg)
 	expectedMigrations := mg.MigrationsCount()
 
@@ -36,7 +37,7 @@ func TestMigrations(t *testing.T) {
 
 	require.Equal(t, expectedMigrations, result.Count)
 
-	mg = NewMigrator(x)
+	mg = NewMigrator(x, &setting.Cfg{})
 	AddMigrations(mg)
 
 	err = mg.Start()

pkg/services/sqlstore/migrations/ualert/permissions.go

@@ -44,7 +44,6 @@ func (m *migration) createFolder(orgID int64, title string) (*dashboard, error)
 		}),
 	}
 	dash := cmd.getDashboardModel()
-	var userId int64 = -1
 
 	uid, err := m.generateNewDashboardUid(dash.OrgId)
 	if err != nil {
@@ -55,9 +54,9 @@ func (m *migration) createFolder(orgID int64, title string) (*dashboard, error)
 	parentVersion := dash.Version
 	dash.setVersion(1)
 	dash.Created = time.Now()
-	dash.CreatedBy = userId
+	dash.CreatedBy = FOLDER_CREATED_BY
 	dash.Updated = time.Now()
-	dash.UpdatedBy = userId
+	dash.UpdatedBy = FOLDER_CREATED_BY
 	metrics.MApiDashboardInsert.Inc()
 
 	if _, err = m.sess.Insert(dash); err != nil {

pkg/services/sqlstore/migrations/ualert/ualert.go

@@ -11,6 +11,14 @@ import (
 const GENERAL_FOLDER = "General Alerting"
 const DASHBOARD_FOLDER = "Migrated %s"
 
+// FOLDER_CREATED_BY us used to track folders created by this migration
+// during alert migration cleanup.
+const FOLDER_CREATED_BY = -8
+
+var migTitle = "move dashboard alerts to unified alerting"
+
+var rmMigTitle = "remove unified alerting data"
+
 type MigrationError struct {
 	AlertId int64
 	Err     error
@@ -26,7 +34,31 @@ func AddMigration(mg *migrator.Migrator) {
 	if os.Getenv("UALERT_MIG") == "iDidBackup" {
 		// TODO: unified alerting DB needs to be extacted into ../migrations.go
 		// so it runs and creates the tables before this migration runs.
-		mg.AddMigration("move dashboard alerts to unified alerting", &migration{})
+		logs, err := mg.GetMigrationLog()
+		if err != nil {
+			mg.Logger.Crit("alert migration failure: could not get migration log", "error", err)
+			os.Exit(1)
+		}
+
+		_, migrationRun := logs[migTitle]
+
+		ngEnabled := mg.Cfg.IsNgAlertEnabled()
+
+		switch {
+		case ngEnabled && !migrationRun:
+			// clear the entry of the migration that
+			err = mg.ClearMigrationEntry(rmMigTitle)
+			if err != nil {
+				mg.Logger.Error("alert migration error: could not clear alert migration for removing data", "error", err)
+			}
+			mg.AddMigration(migTitle, &migration{})
+		case !ngEnabled && migrationRun:
+			err = mg.ClearMigrationEntry(migTitle)
+			if err != nil {
+				mg.Logger.Error("alert migration error: could not clear alert migration", "error", err)
+			}
+			mg.AddMigration(rmMigTitle, &rmMigration{})
+		}
 	}
 }
 
@@ -184,3 +216,45 @@ func (m *migration) Exec(sess *xorm.Session, mg *migrator.Migrator) error {
 
 	return nil
 }
+
+type rmMigration struct {
+	migrator.MigrationBase
+}
+
+func (m *rmMigration) SQL(dialect migrator.Dialect) string {
+	return "code migration"
+}
+
+func (m *rmMigration) Exec(sess *xorm.Session, mg *migrator.Migrator) error {
+	_, err := sess.Exec("delete from alert_rule")
+	if err != nil {
+		return err
+	}
+
+	_, err = sess.Exec("delete from alert_rule_version")
+	if err != nil {
+		return err
+	}
+
+	_, err = sess.Exec("delete from dashboard_acl where dashboard_id IN (select id from dashboard where created_by = ?)", FOLDER_CREATED_BY)
+	if err != nil {
+		return err
+	}
+
+	_, err = sess.Exec("delete from dashboard where created_by = ?", FOLDER_CREATED_BY)
+	if err != nil {
+		return err
+	}
+
+	_, err = sess.Exec("delete from alert_configuration")
+	if err != nil {
+		return err
+	}
+
+	_, err = sess.Exec("delete from alert_instance")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

pkg/services/sqlstore/migrator/migrator.go

@@ -6,6 +6,7 @@ import (
 
 	_ "github.com/go-sql-driver/mysql"
 	"github.com/grafana/grafana/pkg/infra/log"
+	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/util/errutil"
 	_ "github.com/lib/pq"
 	_ "github.com/mattn/go-sqlite3"
@@ -17,6 +18,7 @@ type Migrator struct {
 	Dialect    Dialect
 	migrations []Migration
 	Logger     log.Logger
+	Cfg        *setting.Cfg
 }
 
 type MigrationLog struct {
@@ -28,12 +30,13 @@ type MigrationLog struct {
 	Timestamp   time.Time
 }
 
-func NewMigrator(engine *xorm.Engine) *Migrator {
+func NewMigrator(engine *xorm.Engine, cfg *setting.Cfg) *Migrator {
 	mg := &Migrator{}
 	mg.x = engine
 	mg.Logger = log.New("migrator")
 	mg.migrations = make([]Migration, 0)
 	mg.Dialect = NewDialect(mg.x)
+	mg.Cfg = cfg
 	return mg
 }
 
@@ -168,6 +171,16 @@ func (mg *Migrator) exec(m Migration, sess *xorm.Session) error {
 	return nil
 }
 
+func (mg *Migrator) ClearMigrationEntry(id string) error {
+	sess := mg.x.NewSession()
+	defer sess.Close()
+	_, err := sess.SQL(`DELETE from migration_log where migration_id = ?`, id).Query()
+	if err != nil {
+		return fmt.Errorf("failed to clear migration entry %v: %w", id, err)
+	}
+	return nil
+}
+
 type dbTransactionFunc func(sess *xorm.Session) error
 
 func (mg *Migrator) inTransaction(callback dbTransactionFunc) error {

pkg/services/sqlstore/sqlstore.go

@@ -85,7 +85,7 @@ func (ss *SQLStore) Init() error {
 	dialect = ss.Dialect
 
 	if !ss.dbCfg.SkipMigrations {
-		migrator := migrator.NewMigrator(ss.engine)
+		migrator := migrator.NewMigrator(ss.engine, ss.Cfg)
 		migrations.AddMigrations(migrator)
 
 		for _, descriptor := range registry.GetServices() {