kra-new/pkg/database/migration/runner.go

122 lines
3.5 KiB
Go

// Package migration owns the application database migration runner. Each data
// module declares its own steps; the root data package only orders and runs
// them.
package migration
import (
"fmt"
"strings"
"gorm.io/gorm"
)
const TableName = "sys_schema_migrations"
type Step struct {
ID string
Migrate func(*gorm.DB) error
}
type record struct {
ID string `gorm:"primaryKey;size:255"`
}
func (record) TableName() string { return TableName }
func Run(db *gorm.DB, steps []Step) error {
if db == nil {
return fmt.Errorf("database is nil")
}
db = db.Session(&gorm.Session{NewDB: true})
if err := repairMigrationTable(db); err != nil {
return err
}
if !db.Session(&gorm.Session{NewDB: true}).Migrator().HasTable(&record{}) {
if err := db.Session(&gorm.Session{NewDB: true}).Migrator().CreateTable(&record{}); err != nil {
return fmt.Errorf("create migration table: %w", err)
}
}
var appliedRows []record
if err := db.Session(&gorm.Session{NewDB: true}).Find(&appliedRows).Error; err != nil {
return fmt.Errorf("load applied migrations: %w", err)
}
applied := make(map[string]struct{}, len(appliedRows))
known := make(map[string]struct{}, len(steps))
for _, row := range appliedRows {
applied[row.ID] = struct{}{}
}
for _, step := range steps {
if step.ID == "" {
return fmt.Errorf("migration id is empty")
}
if _, duplicate := known[step.ID]; duplicate {
return fmt.Errorf("duplicate migration id %q", step.ID)
}
known[step.ID] = struct{}{}
}
for id := range applied {
if _, ok := known[id]; !ok {
return fmt.Errorf("unknown applied migration %q", id)
}
}
for _, step := range steps {
if _, ok := applied[step.ID]; ok {
continue
}
if step.Migrate == nil {
return fmt.Errorf("migration %q has no function", step.ID)
}
if err := step.Migrate(db.Session(&gorm.Session{NewDB: true})); err != nil {
return fmt.Errorf("apply migration %q: %w", step.ID, err)
}
if err := db.Session(&gorm.Session{NewDB: true}).Create(&record{ID: step.ID}).Error; err != nil {
return fmt.Errorf("record migration %q: %w", step.ID, err)
}
}
return nil
}
func repairMigrationTable(db *gorm.DB) error {
clean := db.Session(&gorm.Session{NewDB: true})
if !clean.Migrator().HasTable(TableName) {
return nil
}
var dataType string
switch clean.Dialector.Name() {
case "mysql":
err := clean.Raw("SELECT DATA_TYPE FROM information_schema.columns WHERE table_schema = DATABASE() AND table_name = ? AND column_name = ?", TableName, "id").Scan(&dataType).Error
if err != nil {
return fmt.Errorf("inspect migration table: %w", err)
}
case "postgres":
err := clean.Raw("SELECT data_type FROM information_schema.columns WHERE table_schema = current_schema() AND table_name = ? AND column_name = ?", TableName, "id").Scan(&dataType).Error
if err != nil {
return fmt.Errorf("inspect migration table: %w", err)
}
case "sqlite":
var rows []struct {
Name string `gorm:"column:name"`
Type string `gorm:"column:type"`
}
if err := clean.Raw("PRAGMA table_info(" + TableName + ")").Scan(&rows).Error; err != nil {
return fmt.Errorf("inspect migration table: %w", err)
}
for _, row := range rows {
if strings.EqualFold(row.Name, "id") {
dataType = row.Type
break
}
}
default:
return nil
}
normalized := strings.ToLower(dataType)
if strings.Contains(normalized, "char") || strings.Contains(normalized, "text") || strings.Contains(normalized, "clob") {
return nil
}
if err := clean.Migrator().DropTable(TableName); err != nil {
return fmt.Errorf("repair invalid migration table: %w", err)
}
return nil
}