Skip to main content
Join the official 2019 Python Developers SurveyStart the survey!

Library that helps you create and migrate DynamoDB databases

Project description

dynamodb-migrator

Build Status Coverage Status PyPI version

A library that helps you create and migrate DynamoDB databases.

As performant DynamoDB is, that does come with the trade-off of being inflexible. Changing column names or adding secondary indexes is impossible.
The recommended approach is to create a new table with the desired properties, and migrate the existing data.
This library will help you do just that.

Usage

  • Write a migration script
  • Execute the migration script as a step in the build pipeline
  • Add to the migration-script as required

Example Script

from migrator.dynamodb_migrator import Migrator
migrator = Migrator()
@migrator.version(1)
@migrator.create(AttributeDefinitions=[{'AttributeName': 'hash_key', 'AttributeType': 'N'}],
                 TableName='my_new_table',
                 KeySchema=[{'AttributeName': 'hash_key', 'KeyType': 'HASH'}],
                 BillingMode='PAY_PER_REQUEST')
def v1(created_table):
    print("Table created using the kwargs provided")
    print("Note that the keyword-args are passed onto boto as is")
    print(created_table)


@migrator.version(2)
@migrator.add_index(AttributeDefinitions=[{'AttributeName': 'postcode', 'AttributeType': 'S'}],
                    LocalSecondaryIndexes=[{'IndexName': 'string',
                                            'KeySchema': [{'AttributeName': 'customer_nr', 'KeyType': 'HASH'},
                                                          {'AttributeName': 'postcode', 'KeyType': 'RANGE'}],
                                            'Projection': {'ProjectionType': 'ALL'}}])
def v2(created_table):
    print("Created a new table with the new index")
    print("Created a DynamoDB stream that sends all updates to the old table to a custom Lambda-function")
    print("The custom Lambda-function sends all updates to the new table")
    print(created_table)


@NotYetImplemented
@migrator.version(3)
@migrator.delete_table("first_table")
def v3(migrate):
    print("About to delete table")
    print("Ensure that all upstream applications point to the new table, before adding this part to the pipeline!")
    migrate()
    print("Table deleted")


@NotYetImplemented
@migrator.version(4)
@migrator.convert(lambda item -> {'id': translate(item.id)})
def v4(migrate):
    print("About to:")
    print(" - Create new table (first_table_v4)")
    print(" - Create a AWS Lambda script that will execute the above lambda, and write the result int he new table")
    print(" - Create DynamoDB Stream on 'first_table' that triggers the new Lambda")
    print(" - Execute a script that automatically updates all existing data")
    print("   (This will trigger all data in 'first_table' to be converted and copied into the new table")
    migrate()
    print("Table with new data is ready to use")

Examples

See the examples-folder.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Files for dynamodb-migrator, version 0.0.4
Filename, size File type Python version Upload date Hashes
Filename, size dynamodb_migrator-0.0.4-py3-none-any.whl (12.5 kB) File type Wheel Python version py3 Upload date Hashes View hashes
Filename, size dynamodb-migrator-0.0.4.tar.gz (7.0 kB) File type Source Python version None Upload date Hashes View hashes

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page