Cleanup lambda functions versions

cleanup_lambda_versions.py

import boto3

client = boto3.client('lambda')


def _clean_function(function_data, dry_run, max_versions):
    skipped_items = 0
    while True:  # list_versions_by_function returns up to 50 versions per call
        versions = client.list_versions_by_function(
            FunctionName=function_data['FunctionArn']
        )['Versions']
        if len(versions) <= max_versions + skipped_items:
            print(
                f"{function_data['FunctionName']}: done. Leaving "
                f"{max_versions + skipped_items} versions"
            )
            break
        for version in versions[:-max_versions]:
            if version['Version'] != function_data['Version']:
                arn = version['FunctionArn']
                if dry_run:
                    print(f'Would delete {arn})')
                else:
                    print(f"Deleting {arn}...")
                    client.delete_function(FunctionName=arn)
            else:
                skipped_items += 1
                if dry_run:
                    print(f"Would keep {version['FunctionArn']}")
        if dry_run:
            for version in versions[-max_versions:]:
                print(f"Would keep {version['FunctionArn']}")
            break  # Would be an infinite loop in case of dry_run


def clean_function_old_versions(function_name, dry_run=True, max_versions=10):
    _clean_function(
        client.get_function(FunctionName=function_name)["Configuration"],
        dry_run=dry_run,
        max_versions=max_versions,
    )


def clean_all_old_versions(dry_run=True, marker=None, max_versions=10):
    if not marker:
        functions = client.list_functions()
    else:
        functions = client.list_functions(Marker=marker)
    for function_data in functions['Functions']:
        _clean_function(function_data, dry_run, max_versions)
    if 'NextMarker' in functions:
        clean_all_old_versions(
            dry_run=dry_run,
            marker=functions['NextMarker'],
            max_versions=max_versions,
        )