mongodb-migrations

mongodb-migrations

MongoDB is a great NoSQL and schema-less database, but if already have data in database and you changed data schema, you need a migration tool to update your existing data.

How to install

• use pip

  $ pip install mongodb-migrations
  

• from source code

  $ python setup.py install
  

How to use it

1. create a fold named migrations
2. create a python file with name in form of TIMESTAMP_description.py , i.e.20160320145400_description.py, otherwise migration file won't be found.
3. in 20160320145400_description.py create a class named Migration and extends BaseMigration
4. implement upgrade method
5. use cli mongodb-migrate to run migrations
6. metastore is an optional parameter of collection name where it stores the previous migrations

Now there is an easier way to create a migration file, command mongodb-migrate-create --description <description> will create an empty migration file in migrations folder or the folder provided by --migrations.

If you don't wish to use the CLI, you can override the MigrationManager -> create_config and then call MigrationManager -> run. Example execution:

    manager = MigrationManager()
    manager.config.config_file = "foobar.ini"
    manager.config._from_ini()
    manager.run()

You can also use the same config to keep multiple keys, the manager allows you access by using:

   ini_config_parser = manager.config.ini_parser
   ini_config_parser.get('foo','bar')

Configuration

mongodb-migrations will try to load config.ini first, if it's not found, default values will be used. If any command line argument is provided, it will override config from configuration file.

Database name or Url is mandatory

config.ini example

[mongo]
host = 127.0.0.1
port = 27017
database = test
migrations = migrations
metastore = database_migrations

alternative config.ini example

[mongo]
url = mongodb://127.0.0.1:27017/test
migrations = migrations

auth-db config.ini example

[mongo]
url = mongodb://127.0.0.1:27017/admin
username = admin
password = secret123
database = test
migrations = migrations
metastore = database_migrations

command line arguments example

mongodb-migrate --host 127.0.0.1 --port 27017 --database test --migrations examples

alternative command line example

mongodb-migrate --url mongodb://127.0.0.1:27017/test --migrations examples

Example

Migration files are located in examples, run following command to run migrations:

$ MONGODB_MIGRATIONS_CONFIG=examples/config.ini mongodb-migrate

For Downgrading the migrations, you need to pass a command line switch --downgrade

To upgrade/downgrade only to a specific migration, use --to_datetime. This command will upgrade to the migration with prefix 20191115180633:

mongodb-migrate --url mongodb://127.0.0.1:27017/test --migrations examples --to_datetime 20191115180633

Getting involved

• if you find any bug or need anything, please log an issue here: Issues

Contributors

• Rohit Garg
• mpgalaxy