Alerting: Fix legacy migration crash when rule name is too long (#55053)

* Extract standardized UID field length to constant

* Extract default length to constant

* Truncate rule names that are too long

* Add tests for name normalization

* Fix whitespace lint error

* Another linter fix

* Empty commit to kick build

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

@@ -99,7 +99,8 @@ func addMigrationInfo(da *dashAlert) (map[string]string, map[string]string) {
 
 func (m *migration) makeAlertRule(cond condition, da dashAlert, folderUID string) (*alertRule, error) {
 	lbls, annotations := addMigrationInfo(&da)
-	lbls["alertname"] = da.Name
+	name := normalizeRuleName(da.Name)
+	lbls["alertname"] = name
 	annotations["message"] = da.Message
 	var err error
 
@@ -110,14 +111,14 @@ func (m *migration) makeAlertRule(cond condition, da dashAlert, folderUID string
 
 	ar := &alertRule{
 		OrgID:           da.OrgId,
-		Title:           da.Name, // TODO: Make sure all names are unique, make new name on constraint insert error.
+		Title:           name, // TODO: Make sure all names are unique, make new name on constraint insert error.
 		UID:             util.GenerateShortUID(),
 		Condition:       cond.Condition,
 		Data:            data,
 		IntervalSeconds: ruleAdjustInterval(da.Frequency),
 		Version:         1,
 		NamespaceUID:    folderUID, // Folder already created, comes from env var.
-		RuleGroup:       da.Name,
+		RuleGroup:       name,
 		For:             duration(da.For),
 		Updated:         time.Now().UTC(),
 		Annotations:     annotations,
@@ -277,3 +278,15 @@ func transExecErr(s string) (string, error) {
 	}
 	return "", fmt.Errorf("unrecognized Execution Error setting %v", s)
 }
+
+func normalizeRuleName(daName string) string {
+	// If we have to truncate, we're losing data and so there is higher risk of uniqueness conflicts.
+	// Append a UID to the suffix to forcibly break any collisions.
+	if len(daName) > DefaultFieldMaxLength {
+		uniq := util.GenerateShortUID()
+		trunc := DefaultFieldMaxLength - 1 - len(uniq)
+		daName = daName[:trunc] + "_" + uniq
+	}
+
+	return daName
+}

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

@@ -2,6 +2,7 @@ package ualert
 
 import (
 	"encoding/json"
+	"strings"
 	"testing"
 
 	"github.com/grafana/grafana/pkg/components/simplejson"
@@ -84,3 +85,48 @@ func TestAddMigrationInfo(t *testing.T) {
 		})
 	}
 }
+
+func TestMakeAlertRule(t *testing.T) {
+	t.Run("when mapping rule names", func(t *testing.T) {
+		t.Run("leaves basic names untouched", func(t *testing.T) {
+			m := newTestMigration(t)
+			da := createTestDashAlert()
+			cnd := createTestDashAlertCondition()
+
+			ar, err := m.makeAlertRule(cnd, da, "folder")
+
+			require.NoError(t, err)
+			require.Equal(t, da.Name, ar.Title)
+			require.Equal(t, ar.Title, ar.RuleGroup)
+		})
+
+		t.Run("truncates very long names to max length", func(t *testing.T) {
+			m := newTestMigration(t)
+			da := createTestDashAlert()
+			da.Name = strings.Repeat("a", DefaultFieldMaxLength+1)
+			cnd := createTestDashAlertCondition()
+
+			ar, err := m.makeAlertRule(cnd, da, "folder")
+
+			require.NoError(t, err)
+			require.Len(t, ar.Title, DefaultFieldMaxLength)
+			uniq := ar.Title[len(ar.Title)-11:]
+			require.Regexp(t, "^_.{10}$", uniq)
+			require.Equal(t, ar.Title, ar.RuleGroup)
+		})
+	})
+}
+
+func createTestDashAlert() dashAlert {
+	return dashAlert{
+		Id:             1,
+		Name:           "test",
+		ParsedSettings: &dashAlertSettings{},
+	}
+}
+
+func createTestDashAlertCondition() condition {
+	return condition{
+		Condition: "A",
+	}
+}

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

@@ -6,6 +6,12 @@ import (
 	"github.com/grafana/grafana/pkg/services/sqlstore/migrator"
 )
 
+// DefaultFieldMaxLength is the standard size for most user-settable string fields in Alerting. Use this for typical string fields, unless you have a special reason not to.
+const DefaultFieldMaxLength = 190
+
+// UIDMaxLength is the standard size for fields that contain UIDs.
+const UIDMaxLength = 40
+
 // AddMigration defines database migrations.
 func AddTablesMigrations(mg *migrator.Migrator) {
 	AddAlertDefinitionMigrations(mg, 60)
@@ -38,13 +44,13 @@ func AddAlertDefinitionMigrations(mg *migrator.Migrator, defaultIntervalSeconds
 		Columns: []*migrator.Column{
 			{Name: "id", Type: migrator.DB_BigInt, IsPrimaryKey: true, IsAutoIncrement: true},
 			{Name: "org_id", Type: migrator.DB_BigInt, Nullable: false},
-			{Name: "title", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "title", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
-			{Name: "condition", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "condition", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
 			{Name: "data", Type: migrator.DB_Text, Nullable: false},
 			{Name: "updated", Type: migrator.DB_DateTime, Nullable: false},
 			{Name: "interval_seconds", Type: migrator.DB_BigInt, Nullable: false, Default: fmt.Sprintf("%d", defaultIntervalSeconds)},
 			{Name: "version", Type: migrator.DB_Int, Nullable: false, Default: "0"},
-			{Name: "uid", Type: migrator.DB_NVarchar, Length: 40, Nullable: false, Default: "0"},
+			{Name: "uid", Type: migrator.DB_NVarchar, Length: UIDMaxLength, Nullable: false, Default: "0"},
 		},
 		Indices: []*migrator.Index{
 			{Cols: []string{"org_id", "title"}, Type: migrator.IndexType},
@@ -87,13 +93,13 @@ func AddAlertDefinitionVersionMigrations(mg *migrator.Migrator) {
 		Columns: []*migrator.Column{
 			{Name: "id", Type: migrator.DB_BigInt, IsPrimaryKey: true, IsAutoIncrement: true},
 			{Name: "alert_definition_id", Type: migrator.DB_BigInt},
-			{Name: "alert_definition_uid", Type: migrator.DB_NVarchar, Length: 40, Nullable: false, Default: "0"},
+			{Name: "alert_definition_uid", Type: migrator.DB_NVarchar, Length: UIDMaxLength, Nullable: false, Default: "0"},
 			{Name: "parent_version", Type: migrator.DB_Int, Nullable: false},
 			{Name: "restored_from", Type: migrator.DB_Int, Nullable: false},
 			{Name: "version", Type: migrator.DB_Int, Nullable: false},
 			{Name: "created", Type: migrator.DB_DateTime, Nullable: false},
-			{Name: "title", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "title", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
-			{Name: "condition", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "condition", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
 			{Name: "data", Type: migrator.DB_Text, Nullable: false},
 			{Name: "interval_seconds", Type: migrator.DB_BigInt, Nullable: false},
 		},
@@ -116,10 +122,10 @@ func AlertInstanceMigration(mg *migrator.Migrator) {
 		Name: "alert_instance",
 		Columns: []*migrator.Column{
 			{Name: "def_org_id", Type: migrator.DB_BigInt, Nullable: false},
-			{Name: "def_uid", Type: migrator.DB_NVarchar, Length: 40, Nullable: false, Default: "0"},
+			{Name: "def_uid", Type: migrator.DB_NVarchar, Length: UIDMaxLength, Nullable: false, Default: "0"},
 			{Name: "labels", Type: migrator.DB_Text, Nullable: false},
-			{Name: "labels_hash", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "labels_hash", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
-			{Name: "current_state", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "current_state", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
 			{Name: "current_state_since", Type: migrator.DB_BigInt, Nullable: false},
 			{Name: "last_eval_time", Type: migrator.DB_BigInt, Nullable: false},
 		},
@@ -158,7 +164,7 @@ func AlertInstanceMigration(mg *migrator.Migrator) {
 
 	mg.AddMigration("add current_reason column related to current_state",
 		migrator.NewAddColumnMigration(alertInstance, &migrator.Column{
-			Name: "current_reason", Type: migrator.DB_NVarchar, Length: 190, Nullable: true,
+			Name: "current_reason", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: true,
 		}))
 }
 
@@ -168,16 +174,16 @@ func AddAlertRuleMigrations(mg *migrator.Migrator, defaultIntervalSeconds int64)
 		Columns: []*migrator.Column{
 			{Name: "id", Type: migrator.DB_BigInt, IsPrimaryKey: true, IsAutoIncrement: true},
 			{Name: "org_id", Type: migrator.DB_BigInt, Nullable: false},
-			{Name: "title", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "title", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
-			{Name: "condition", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "condition", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
 			{Name: "data", Type: migrator.DB_Text, Nullable: false},
 			{Name: "updated", Type: migrator.DB_DateTime, Nullable: false},
 			{Name: "interval_seconds", Type: migrator.DB_BigInt, Nullable: false, Default: fmt.Sprintf("%d", defaultIntervalSeconds)},
 			{Name: "version", Type: migrator.DB_Int, Nullable: false, Default: "0"},
-			{Name: "uid", Type: migrator.DB_NVarchar, Length: 40, Nullable: false, Default: "0"},
+			{Name: "uid", Type: migrator.DB_NVarchar, Length: UIDMaxLength, Nullable: false, Default: "0"},
 			// the following fields will correspond to a dashboard (or folder) UIID
-			{Name: "namespace_uid", Type: migrator.DB_NVarchar, Length: 40, Nullable: false},
+			{Name: "namespace_uid", Type: migrator.DB_NVarchar, Length: UIDMaxLength, Nullable: false},
-			{Name: "rule_group", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "rule_group", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
 			{Name: "no_data_state", Type: migrator.DB_NVarchar, Length: 15, Nullable: false, Default: "'NoData'"},
 			{Name: "exec_err_state", Type: migrator.DB_NVarchar, Length: 15, Nullable: false, Default: "'Alerting'"},
 		},
@@ -259,16 +265,16 @@ func AddAlertRuleVersionMigrations(mg *migrator.Migrator) {
 		Columns: []*migrator.Column{
 			{Name: "id", Type: migrator.DB_BigInt, IsPrimaryKey: true, IsAutoIncrement: true},
 			{Name: "rule_org_id", Type: migrator.DB_BigInt},
-			{Name: "rule_uid", Type: migrator.DB_NVarchar, Length: 40, Nullable: false, Default: "0"},
+			{Name: "rule_uid", Type: migrator.DB_NVarchar, Length: UIDMaxLength, Nullable: false, Default: "0"},
 			// the following fields will correspond to a dashboard (or folder) UID
-			{Name: "rule_namespace_uid", Type: migrator.DB_NVarchar, Length: 40, Nullable: false},
+			{Name: "rule_namespace_uid", Type: migrator.DB_NVarchar, Length: UIDMaxLength, Nullable: false},
-			{Name: "rule_group", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "rule_group", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
 			{Name: "parent_version", Type: migrator.DB_Int, Nullable: false},
 			{Name: "restored_from", Type: migrator.DB_Int, Nullable: false},
 			{Name: "version", Type: migrator.DB_Int, Nullable: false},
 			{Name: "created", Type: migrator.DB_DateTime, Nullable: false},
-			{Name: "title", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "title", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
-			{Name: "condition", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "condition", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
 			{Name: "data", Type: migrator.DB_Text, Nullable: false},
 			{Name: "interval_seconds", Type: migrator.DB_BigInt, Nullable: false},
 			{Name: "no_data_state", Type: migrator.DB_NVarchar, Length: 15, Nullable: false, Default: "'NoData'"},
@@ -368,9 +374,9 @@ func AddProvisioningMigrations(mg *migrator.Migrator) {
 		Columns: []*migrator.Column{
 			{Name: "id", Type: migrator.DB_BigInt, IsPrimaryKey: true, IsAutoIncrement: true},
 			{Name: "org_id", Type: migrator.DB_BigInt, Nullable: false},
-			{Name: "record_key", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "record_key", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
-			{Name: "record_type", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "record_type", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
-			{Name: "provenance", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "provenance", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
 		},
 		Indices: []*migrator.Index{
 			{Cols: []string{"record_type", "record_key", "org_id"}, Type: migrator.UniqueIndex},
@@ -386,9 +392,9 @@ func AddAlertImageMigrations(mg *migrator.Migrator) {
 		Name: "alert_image",
 		Columns: []*migrator.Column{
 			{Name: "id", Type: migrator.DB_BigInt, IsPrimaryKey: true, IsAutoIncrement: true},
-			{Name: "token", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "token", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
-			{Name: "path", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "path", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
-			{Name: "url", Type: migrator.DB_NVarchar, Length: 190, Nullable: false},
+			{Name: "url", Type: migrator.DB_NVarchar, Length: DefaultFieldMaxLength, Nullable: false},
 			{Name: "created_at", Type: migrator.DB_DateTime, Nullable: false},
 			{Name: "expires_at", Type: migrator.DB_DateTime, Nullable: false},
 		},