GCR docker retag image without pulling

gcr_docker_image_retag.sh

#!/usr/bin/env

# Generated via GPT-4

# Check if the correct number of arguments is provided
if [ "$#" -ne 2 ]; then
    echo "Usage: $0 source-image destination-image"
    exit 1
fi

# Assign the arguments to variables
SOURCE_IMAGE="$1"
DESTINATION_IMAGE="$2"

# Extract the registry, project ID, and image name from the source and destination images
SOURCE_REGISTRY=$(echo "${SOURCE_IMAGE}" | awk -F/ '{print $1}')
SOURCE_PROJECT_ID=$(echo "${SOURCE_IMAGE}" | awk -F/ '{print $2}')
SOURCE_IMAGE_NAME=$(echo "${SOURCE_IMAGE}" | awk -F/ '{print $3}')

DESTINATION_REGISTRY=$(echo "${DESTINATION_IMAGE}" | awk -F/ '{print $1}')
DESTINATION_PROJECT_ID=$(echo "${DESTINATION_IMAGE}" | awk -F/ '{print $2}')
DESTINATION_IMAGE_NAME=$(echo "${DESTINATION_IMAGE}" | awk -F/ '{print $3}')

# Get the GCR authentication token
ACCESS_TOKEN=$(gcloud auth print-access-token)

# Fetch the source image manifest
MANIFEST=$(curl -s -H "Authorization: Bearer $ACCESS_TOKEN" -H "Accept: application/vnd.docker.distribution.manifest.v2+json" "https://${SOURCE_REGISTRY}/v2/${SOURCE_PROJECT_ID}/${SOURCE_IMAGE_NAME}/manifests/latest")

# Push the manifest to the destination image
curl -X PUT -H "Authorization: Bearer $ACCESS_TOKEN" -H "Content-Type: application/vnd.docker.distribution.manifest.v2+json" -d "${MANIFEST}" "https://${DESTINATION_REGISTRY}/v2/${DESTINATION_PROJECT_ID}/${DESTINATION_IMAGE_NAME}/manifests/latest"