// OpenDB returns a new gorm.DB instance.
func OpenDB(uri string) (*DB, error) {
u, err := url.Parse(uri)
if err != nil {
return nil, err
}
conn, err := sql.Open(u.Scheme, uri)
if err != nil {
return nil, err
}
db, err := gorm.Open(u.Scheme, conn)
if err != nil {
return nil, err
}
m := migrate.NewPostgresMigrator(conn)
// Run all migrations in a single transaction, so they will be rolled
// back as one. This is almost always the behavior that users would want
// when upgrading Empire. If a new release has multiple migrations, and
// one of those fails, it's easier for them if the entire upgrade rolls
// back instead of getting stuck in failed state.
m.TransactionMode = migrate.SingleTransaction
return &DB{
DB: &db,
uri: uri,
migrator: m,
}, nil
}
// migrate runs all available migrations on a pgSQL database.
func migrateDatabase(db *sql.DB) error {
log.Info("running database migrations")
err := migrate.NewPostgresMigrator(db).Exec(migrate.Up, migrations.Migrations...)
if err != nil {
return fmt.Errorf("pgsql: an error occured while running migrations: %v", err)
}
log.Info("database migration ran successfully")
return nil
}
func TestMigrate_Locking(t *testing.T) {
db := newDB(t)
defer db.Close()
migrator := migrate.NewMigrator(db)
if *database == Postgres {
migrator = migrate.NewPostgresMigrator(db)
}
err := migrator.Exec(migrate.Up, testMigrations...)
assert.NoError(t, err)
assertSchema(t, `
people
CREATE TABLE people (id int, first_name text)
`, db)
assert.Equal(t, []int{1, 2}, appliedMigrations(t, db))
var called int
// Generates a migration that sends on the given channel when it starts.
migration := migrate.Migration{
ID: 3,
Up: func(tx *sql.Tx) error {
called++
_, err := tx.Exec(`INSERT INTO people (id, first_name) VALUES (1, 'Eric')`)
return err
},
}
m1 := make(chan error)
m2 := make(chan error)
// Start two migrations in parallel.
go func() {
m1 <- migrator.Exec(migrate.Up, migration)
}()
go func() {
m2 <- migrator.Exec(migrate.Up, migration)
}()
assert.Nil(t, <-m1)
assert.Nil(t, <-m2)
assert.Equal(t, 1, called)
assertSchema(t, `
people
CREATE TABLE people (id int, first_name text)
`, db)
assert.Equal(t, []int{1, 2, 3}, appliedMigrations(t, db))
}