Trimming AWS Lambda versions

This last tip is specific to AWS Lambda. You may have noticed in other chapters that there are the following lines in the serverless.yml file:

plugins:
  - serverless-prune-plugin

By default, each time you deploy a new version of an AWS Lambda function, AWS will help out by keeping the old version around. In a development system where you may be deploying dozens of times a day, this can become quite wasteful and, as cheap as storage is, it's not unlimited. Also, in the case of a production system that has a lifetime of years, the cost of all the old versions can add up.

If you're using the Serverless Framework, there is an easy way around this. If you're not using the Serverless Framework, however, it would be no more than a day's work to write a small script to do this for you. The serverless-prune-plugin will keep only a certain number of Lambda versions for you and delete the rest. The number of versions to keep is configurable and trimming happens whenever you...