Serverless Prune Plugin

Following deployment, the Serverless Framework does not purge previous versions of functions from AWS, so the number of deployed versions can grow out of hand rather quickly. This plugin allows pruning of all but the most recent version(s) of managed functions from AWS. This plugin is compatible with Serverless 1.x and higher.

Installation

Install with npm:

npm install --save-dev serverless-prune-plugin

And then add the plugin to your serverless.yml file:

plugins:
  - serverless-prune-plugin

Alternatively, install with the Serverless plugin command (Serverless Framework 1.22 or higher):

sls plugin install -n serverless-prune-plugin

Usage

In the project root, run:

sls prune -n <number of version to keep>

This will delete all but the n-most recent versions of each function deployed. Versions referenced by an alias are automatically preserved.

Single Function

A single function can be targeted for cleanup:

sls prune -n <number of version to keep> -f helloWorld

Region/Stage

The previous usage examples prune the default stage in the default region. Use --stage and --region to specify:

sls prune -n <number of version to keep> --stage production --region eu-central-1

Automatic Pruning

This plugin can also be configured to run automatically, following a deployment. Configuration of automatic pruning is within the custom property of serverless.yml. For example:

custom:
  prune:
    automatic: true
    number: 3

To run automatically, the automatic property of prune must be set to true and the number of versions to keep must be specified. It is possible to set number to 0. In this case, the plugin will delete all the function versions (except $LATEST); this is useful when disabling function versioning for an already-deployed stack.

Layers

This plugin can also prune Lambda Layers in the same manner that it prunes functions. You can specify a Lambda Layer, or add the flag, includeLayers:

custom:
  prune:
    automatic: true
    includeLayers: true
    number: 3

Dry Run

A dry-run will preview the deletion candidates, without actually performing the pruning operations:

sls prune -n <number of version to keep> --dryRun

Additional Help

See:

sls prune --help

Permissions Required

To run this plugin, the user will need to be allowed the following permissions in AWS:

• lambda:listAliases
• lambda:listVersionsByFunction
• lambda:deleteFunction
• lambda:listLayerVersions
• lambda:deleteLayerVersion

Common Questions

How do I set up different pruning configurations per region/stage?

Several suggestions are available in this thread.

Can I just disable versioning entirely?

Absolutely. While Serverless Framework has it enabled by default, versioning can be disabled.

License

Copyright (c) 2017 Clay Gregory. See the included LICENSE for rights and limitations under the terms of the MIT license.