Helper script for cleaning up inactive task definition revisions across regions

delete-inactive_task_definition_revisions.sh

#!/usr/bin/env bash

# On Feb 27, 2023, Amazon ECS supports deletion of inactive task definition revisions:
#
#   Announcement:
#   - https://aws.amazon.com/about-aws/whats-new/2023/02/amazon-ecs-deletion-inactive-task-definition-revisions/
#
#   Blog Post:
#   - https://aws.amazon.com/blogs/containers/announcing-amazon-ecs-task-definition-deletion/
#
#   Developer Guide:
#   - https://docs.aws.amazon.com/AmazonECS/latest/developerguide/delete-task-definition-v2.html
#
#   Here's the sample script could helps you cleanup all INACTIVE task definition revisions at once.
#
#   Disclaimer:
#   - You should always test the script under your test environment, DO NOT use it on production without tests. Use it with caution.
#
# Usage:
#
#   #### run with DRY_RUN mode on
#   $ ./delete-inactive_task_definition_revisions.sh
#
#   #### explicitly run with DRY_RUN mode on
#   $ DRY_RUN=true ./delete-inactive_task_definition_revisions.sh
#
#   #### explicitly run with DRY_RUN mode off (will send out delete target resource)
#   $ DRY_RUN=false ./delete-inactive_task_definition_revisions.sh
#

declare DRY_RUN=${DRY_RUN:-true}

echo "Searching for AWS Regions... "
regions=($(aws ec2 describe-regions --no-cli-pager --filters 'Name=opt-in-status,Values=opt-in-not-required' --query 'Regions[*][RegionName]' --output text))
echo "Found ${#regions[@]} AWS regions"
echo

for region in "${regions[@]}"; do
  echo "Processing region: ${region}"

  printf "Searching for Inactive Task Definition Revisions... "
  inactive_task_definition_revisions=($(aws ecs list-task-definitions --no-cli-pager --region "${region}" --status "INACTIVE" --query "taskDefinitionArns[]" --output text))
  echo "Found ${#inactive_task_definition_revisions[@]} Inactive Task Definition(s)"

  for inactive_task_definition_revision in "${inactive_task_definition_revisions[@]}"; do
    if [ "${DRY_RUN}" != "false" ]; then
      printf "*** \e[1;32m[DRY_RUN: ON]\e[m Found \"%s\", skipped ***\n" "${inactive_task_definition_revision}"
    else
      printf "*** \e[1;31m[DRY_RUN: OFF]\e[m Found \"%s\", deleting ***\n" "${inactive_task_definition_revision}"
      aws ecs delete-task-definitions --no-cli-pager --region "${region}" --task-definitions "${inactive_task_definition_revision}" --output json
    fi
  done
  echo
  sleep 0.3 # To avoid being blocked by throttle
done