Flit

Flit is a Go package that implements SQL database migrations. It is built on top of Go's standard database/sql package. There are many packages like this one and all of them are better, but Flit is small and easy to understand.

Flit reads migrations from .sql files and executes each one as a single SQL statement. Completed migrations are recorded in the flits table, which is created automatically.

To use Flit, create a new migrator and call Migrate when your process starts. You can handle concurrent processes by configuring a guard function like the following example.

Example

package main

import (
	"context"
	"database/sql"
	"fmt"
	"os"

	"github.com/180-studios/flit"

	_ "github.com/go-sql-driver/mysql"
)

func main() {
	db, err := sql.Open("mysql", os.Getenv("MYSQL_DSN"))
	if err != nil {
		panic(err)
	}

	defer db.Close()

	dir := os.Args[1]

	// read migrations from dir/*.sql (or embed them)
	// manage concurrency with MySQL's GET_LOCK/RELEASE_LOCK
	m := flit.New(db, os.DirFS(dir), flit.WithGuard(flit.GuardMySQL))
	applied, err := m.Migrate(context.Background())
	if err != nil {
		panic(err)
	}

	fmt.Println(applied)
}

Development

The MySQL tests are skipped unless the TEST_MYSQL_DSN environment variable is set.

Dependencies

Flit doesn't have any runtime dependencies other than the standard library. The tests and examples depend on the github.com/go-sql-driver/mysql and github.com/mattn/go-sqlite3 modules.