ACR Cleaner

Description

A script to clean up an Azure container registry by deleting dangling images and images which are older than a specified period of time (in days) if they are not being used. It was tested and validated against container registries with single-architecture images.

Getting Started

Prerequisites

1. Set environment variables:

   export AZURE_CLIENT_ID=<AZURE_CLIENT_ID>
   export AZURE_CLIENT_SECRET=<AZURE_CLIENT_SECRET>
   export AZURE_TENANT_ID=<AZURE_TENANT_ID>
   export AZURE_SUBSCRIPTION_ID=<AZURE_SUBSCRIPTION_ID>

2. Install requirements:

   pip install poetry
   poetry install --without dev

3. Get a list of images in use:

   mapfile -t DEPLOYED_IMAGES <<<"$(kubectl get pods \
      --all-namespaces \
      --output jsonpath='{range .items[*]}{range .status.containerStatuses[*]}{.imageID}{"\n"}{end}' \
      | grep <REGISTRY_NAME> | sort | uniq)"
   
   # Convert the array to a CSV "list" which can then be passed as input to the ACR cleaner script
   DEPLOYED_IMAGES_CSV=$(IFS=','; echo "${DEPLOYED_IMAGES[*]}")

Usage

Usage: poetry run acr_cleaner.py REGISTRY_NAME REGISTRY_RESOURCE_GROUP MAX_IMAGE_AGE DEPLOYED_IMAGES

Arguments:
    REGISTRY_NAME              The name of the container registry
    REGISTRY_RESOURCE_GROUP    The resource group where the container registry is deployed
    MAX_IMAGE_AGE              The max age (in days) an image can have
    DEPLOYED_IMAGES            A comma-separated list of images that are currently deployed (in use). These will be handled as exceptions
                               and therefore they will not be deleted even if they are older than the `MAX_IMAGE_AGE` argument