doc22940 / migrate

Database migrations. CLI and Golang library.

migrate

Database migrations written in Go. Use as CLI or import as library.

• Migrate reads migrations from sources and applies them in correct order to a database.
• Drivers are "dumb", migrate glues everything together and makes sure the logic is bulletproof. (Keeps the drivers lightweight, too.)
• Database drivers don't assume things or try to correct user input. When in doubt, fail.

Forked from mattes/migrate

Databases

Database drivers run migrations. Add a new database?

• PostgreSQL
• Redshift
• Ql
• Cassandra
• SQLite (todo #165)
• MySQL/ MariaDB
• Neo4j
• MongoDB
• CrateDB (todo #170)
• Shell (todo #171)
• Google Cloud Spanner
• CockroachDB
• ClickHouse
• Firebird
• MS SQL Server

Database URLs

Database connection strings are specified via URLs. The URL format is driver dependent but generally has the form: dbdriver://username:password@host:port/dbname?option1=true&option2=false

Any reserved URL characters need to be escaped. Note, the % character also needs to be escaped

Explicitly, the following characters need to be escaped: !, #, $, %, &, ', (, ), *, +, ,, /, :, ;, =, ?, @, [, ]

It's easiest to always run the URL parts of your DB connection URL (e.g. username, password, etc) through an URL encoder. See the example Python snippets below:

$ python3 -c 'import urllib.parse; print(urllib.parse.quote(input("String to encode: "), ""))'
String to encode: FAKEpassword!#$%&'()*+,/:;=?@[]
FAKEpassword%21%23%24%25%26%27%28%29%2A%2B%2C%2F%3A%3B%3D%3F%40%5B%5D
$ python2 -c 'import urllib; print urllib.quote(raw_input("String to encode: "), "")'
String to encode: FAKEpassword!#$%&'()*+,/:;=?@[]
FAKEpassword%21%23%24%25%26%27%28%29%2A%2B%2C%2F%3A%3B%3D%3F%40%5B%5D
$

Migration Sources

Source drivers read migrations from local or remote sources. Add a new source?

• Filesystem - read from filesystem
• Go-Bindata - read from embedded binary data (jteeuwen/go-bindata)
• Github - read from remote Github repositories
• Github Enterprise - read from remote Github Enterprise repositories
• Gitlab - read from remote Gitlab repositories
• AWS S3 - read from Amazon Web Services S3
• Google Cloud Storage - read from Google Cloud Platform Storage

CLI usage

• Simple wrapper around this library.
• Handles ctrl+c (SIGINT) gracefully.
• No config search paths, no config files, no magic ENV var injections.

CLI Documentation

Basic usage

$ migrate -source file://path/to/migrations -database postgres://localhost:5432/database up 2

Docker usage

$ docker run -v {{ migration dir }}:/migrations --network host migrate/migrate
    -path=/migrations/ -database postgres://localhost:5432/database up 2

Use in your Go project

• API is stable and frozen for this release (v3 & v4).
• Uses Go modules to manage dependencies.
• To help prevent database corruptions, it supports graceful stops via GracefulStop chan bool.
• Bring your own logger.
• Uses io.Reader streams internally for low memory overhead.
• Thread-safe and no goroutine leaks.

Go Documentation

import (
    "github.com/golang-migrate/migrate/v4"
    _ "github.com/golang-migrate/migrate/v4/database/postgres"
    _ "github.com/golang-migrate/migrate/v4/source/github"
)

func main() {
    m, err := migrate.New(
        "github://mattes:personal-access-token@mattes/migrate_test",
        "postgres://localhost:5432/database?sslmode=enable")
    m.Steps(2)
}

Want to use an existing database client?

import (
    "database/sql"
    _ "github.com/lib/pq"
    "github.com/golang-migrate/migrate/v4"
    "github.com/golang-migrate/migrate/v4/database/postgres"
    _ "github.com/golang-migrate/migrate/v4/source/file"
)

func main() {
    db, err := sql.Open("postgres", "postgres://localhost:5432/database?sslmode=enable")
    driver, err := postgres.WithInstance(db, &postgres.Config{})
    m, err := migrate.NewWithDatabaseInstance(
        "file:///migrations",
        "postgres", driver)
    m.Steps(2)
}

Getting started

Go to getting started

Tutorials

• CockroachDB
• PostgreSQL

(more tutorials to come)

Migration files

Each migration has an up and down migration. Why?

1481574547_create_users_table.up.sql
1481574547_create_users_table.down.sql

Best practices: How to write migrations.

Versions

Version	Supported?	Import	Notes
master	✅	import "github.com/golang-migrate/migrate/v4"	New features and bug fixes arrive here first
v4	✅	import "github.com/golang-migrate/migrate/v4"	Used for stable releases
v3	❌	import "github.com/golang-migrate/migrate" (with package manager) or import "gopkg.in/golang-migrate/migrate.v3" (not recommended)	DO NOT USE - No longer supported

Development and Contributing

Yes, please! Makefile is your friend, read the development guide.

Also have a look at the FAQ.

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Looking for alternatives? https://awesome-go.com/#database.