Aurora Serverless: Schema migrations.

Q: How do you run schema migrations in a serverless environment on AWS?

A: Use Cloudformation custom resources.

Cloudformation custom resources allow you to trigger a Lambda function at stack deployment time. For a primer on custom resources, check out this blog by Alex Debrie.

Here’s what you need

• A Lambda function to run the schema migration scripts against the RDS database.
• A Cloudformation custom resource to trigger the Lambda function at deployment time.

Because the schema migration is executed in a lambda function, you can use all the exiting ORM libraries you are familiar with, such as SQLAlchemy and Alembic for Python.

Check out this repo for a working example: https://github.com/murali44/RDS-Aurora-Serverless