Versioned migrations for MongoDB for Golang 1.20

Fork from: github.com/xakep666/go-mongodb-migrate

This package allows to perform versioned migrations on your MongoDB using mongo-go-driver. Inspired by go-pg migrations.

Table of Contents

• Prerequisites
• Installation
• Usage
  • Use case #1. Migrations in files. (#use-case-2-migrations-in-application-code)
• How it works?
• License

Prerequisites

• Golang >= 1.20

Installation

go get -v -u github.com/erodriguezg/go-mongodb-migrate

Usage

Use case #1. Migrations in files.

• Create a package with migration files. File name should be like <version>_<description>.go.

1_add-my-index.go

package migrations

import (
	_ "embed"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	migrate "github.com/erodriguezg/go-mongodb-migrate"
)

//go:embed 1_add-my-index.go
var migration001 string

func init() {
	migrate.Register(&migration001, func(db *mongo.Database) error {
		opt := options.Index().SetName("my-index")
		keys := bson.D{{"my-key", 1}}
		model := mongo.IndexModel{Keys: keys, Options: opt}
		_, err := db.Collection("my-coll").Indexes().CreateOne(context.TODO(), model)
		if err != nil {
			return err
		}

		return nil
	}, func(db *mongo.Database) error {
		_, err := db.Collection("my-coll").Indexes().DropOne(context.TODO(), "my-index")
		if err != nil {
			return err
		}
		return nil
	})
}

• Import it in your application.

import (
    ...
    migrate "github.com/erodriguezg/go-mongodb-migrate"
    _ "path/to/migrations_package" // database migrations
    ...
)

• Run migrations.

func MongoConnect(host, user, password, database string) (*mongo.Database, error) {
	uri := fmt.Sprintf("mongodb://%s:%s@%s:27017", user, password, host)
	opt := options.Client().ApplyURI(uri)
	client, err := mongo.NewClient(opt)
	if err != nil {
		return nil, err
	}
	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
	defer cancel()
	err = client.Connect(ctx)
	if err != nil {
		return nil, err
	}
	db = client.Database(database)
	migrate.SetDatabase(db)
	migrate.SetEnabled(true) // enable o disable the migrations process
	migrate.SetAutoRepair(true) // enable o disable the auto repair process
	if err := migrate.Up(migrate.AllAvailable); err != nil {
		return nil, err
	}
	return db, nil
}

How it works?

This package creates a special collection (by default it`s name is "migrations") for versioning. In this collection stored documents like

{
    "_id": "<mongodb-generated id>",
    "version": 1,
    "description": "add my-index",
    "timestamp": "<when applied>",
	"hash" : "<the calculate hash of the input file>"
}

Current database version determined as version from latest inserted document.

You can change collection name using SetMigrationsCollection methods. Remember that if you want to use custom collection name you need to set it before running migrations.

What is new?

Taking the fork as the base of the project, new functionality is added:

- Added Drone pipeline
- Added Makefile
- Refactor of the code in pkg
- File hash calculation
- Auto repair logic
- Enable / Disable migrations logic