About

Alley allows you to create, execute and rollback migrations for MongoDB in python using MongoEngine.

Migration files are stored in a specified migrations directory. Each file contains up and down methods: python functions that receive the MongoEngine database connection. After execution a record about the migration run is added to db_migrations mongo collection. Migrations can be run from the command line, such as in a deployment script, or imported.

Forked from https://bitbucket.org/letsignitcloud/flask-mongoengine-migrations by Andrey Zhukov.

Install

pip install alley

Usage

Create migration

alley <PATH to migrations parent directory> create <name>

Creates migration file <id>_<name>.py with no-op up and down methods. Also creates a migrations directory at this path if none exists.

Show status

alley <PATH> status

Show migrations available for execution.

Run migration

alley <PATH> up [migration_id]

Save migration as having been run, but skip execution:

alley <PATH> up [migration_id] --fake

Rollback migration

alley <PATH> down <migration_id>

Connecting to MongoDB

Before the <PATH> parameter, specify your mongo connection.

alley -db <database name> -u <user> -w <password> -a <authentication database> -h <host> -p <port> <PATH> <command> [options]

To see all available command line options run:

alley --help

Examples

Remove field

def up(db):
    db['your_collection'].update_many(
        {'some_field': {'$exists': True}},
        {'$unset': {'some_field': 1}}
    )

Run migration from code

from mongoengine.connection import get_db, connect

connect(**connection_args)
db = get_db()
path = os.path.dirname(__file__) # where __file__ is a sibling of migrations/

Migrations(path, db).up()

Test

python setup.py test

Todo

• Other ways to set mongo connection parameters, such as environment variables.
• Auto-detect migration directory.