Remove multiple GCP Docker registry images

gcp_registry_clean.sh

#!/bin/bash

GOOGLE_PROJECT_ID="example-id"
GCLOUD_SERVICE_KEY="serviceAccount.json content"
# eu.grc.io, etc...
ZONE="gcr.io"
SERVICE_ACCOUNT_FILE_NAME="google_service_account.json"

function gcp_auth {
    echo "${GCLOUD_SERVICE_KEY}" | base64 -d > $SERVICE_ACCOUNT_FILE_NAME
    gcloud auth activate-service-account --key-file=$SERVICE_ACCOUNT_FILE_NAME
    gcloud config set project $GOOGLE_PROJECT_ID
}


function delete_images {
    # example-folder-name
    local REPOSITORY_FOLDER="${1}"
    local REPOSITORY="${ZONE}/${GOOGLE_PROJECT_ID}/${REPOSITORY_FOLDER}"

    local IMAGES=$(gcloud container images list --repository=$REPOSITORY --format='get(name)')
    # 10 = KEEPS LAST 10 IMAGES
    local NUMBER_OF_IMAGES_TO_KEEP="${2}"

    for image in $IMAGES
    do
        echo "current image: ${image}"
        DIGEST_TO_REMOVE=$(gcloud container images list-tags ${image} --sort-by=~TIMESTAMP --format='get(digest)'|tail + $NUMBER_OF_IMAGES_TO_KEEP)
        for digest in $DIGEST_TO_REMOVE
        do
            gcloud container images delete -q --force-delete-tags "${image}@${digest}"
        done
    done
}

function clear_auth_file {
    rm $SERVICE_ACCOUNT_FILE_NAME
}