morph

A database migration tool designed to make schema migrations easy.

Morph

As an application evolves, the data flowing inside inevitably evolves along with it. If you have an application that persists the data in a relational database, the way you store the data will probably change over time. Morph is a database migration tool that helps you to apply your migrations. It is written with Go so you can use it from your Go application as well. Read our blog post to learn more about the motivation behind this project.

Usage

Morph can be used as a library or a CLI tool.

Library

import (
    "context"

    "github.com/mattermost/morph"
    "github.com/mattermost/morph/drivers/mysql"
    "github.com/mattermost/morph/sources/embedded"
)

src, err := embedded.WithInstance(&embedded.AssetSource{
    Names: []string{}, // add migration file names
    AssetFunc: func(name string) ([]byte, error) {
        return []byte{}, nil // should return the file contents
    },
})
if err != nil {
    return err
}
defer src.Close()

driver, err := mysql.WithInstance(db)
if err != nil {
    return err
}

engine, err := morph.New(context.Background(), driver, src)
if err != nil {
    return err
}
defer engine.Close()

engine.ApplyAll()

CLI

To install morph you can use:

go install github.com/mattermost/morph/cmd/morph@latest

Then you can apply your migrations like below:

morph apply up --driver postgres --dsn "postgres://user:pass@localhost:5432/mydb?sslmode=disable" --path ./db/migrations/postgres --number 1

Migration Files

The migrations files should have an up and down versions. The program requires each migration to be reversible, and the naming of the migration should be in the following form:

0000000001_create_user.up.sql
0000000001_create_user.down.sql

The first part will be used to determine the order in which the migrations should be applied and the next part until the up|down.sql suffix will be the migration name.

The program requires this naming convention to be followed as it saves the order and names of the migrations. Also, it can rollback migrations with the down files.

LICENSE

MIT