List all non-Google/GKE/k8s/Stackdriver images in a cluster using fully qualified names and without tags.

kubectl-list_images

#!/usr/bin/env bash

kubectl get all --all-namespaces -o yaml \
  | grep \ image: \
  | egrep -iv 'image:\ sha256|(gke|k8s)\.gcr\.io|gcr\.io/(gke|google|stackdriver|kubernetes)-.*' \
  | perl -pe 's#^[\W-]+image:\W+([^\@:]+)([:@].+)?$#$1#i' \
  | perl -pe 's#^([a-z0-9-_]+)$#docker.io/library/$1#i' \
  | perl -pe 's#^([a-z0-9-_/]+)$#docker.io/$1#i' \
  | sort -n | uniq

To install for use with Krew:

curl -s https://gist.githubusercontent.com/davidalger/e500dc8e5f0e642a30e8f21caef74406/raw/kubectl-list_images \
    > /usr/local/bin/kubectl-list_images

chmod +x /usr/local/bin/kubectl-list_images

To run it:

kubectl list-images