Push local Docker images to Google Cloud Registry

docker-push-gcr.sh

#!/usr/bin/env bash

# Exit immediately on error
set -o errexit
# All variables should be explicitly declared
set -o nounset
# Exit on error in a loop
set -o pipefail

# Find local images tagged as ``example/*:latest`` and push them as ``gcr.io/my-example-project/*:latest``

: "${GCR_URL:=gcr.io}"
: "${GCP_PROJECT:=my-example-project}"
: "${DOCKER_IMAGES_TAG:=latest}"
: "${DOCKER_LOCAL_REPO:=example}"

GCP_GCR_URI="${GCR_URL}/${GCP_PROJECT}"

LOCAL_IMAGES="$(docker images --filter="reference=${DOCKER_LOCAL_REPO}/*:${DOCKER_IMAGES_TAG}" | tail -n +2 | awk '{print $1":"$2;}')"
for repo in $LOCAL_IMAGES; do
    tag="${GCP_GCR_URI}/${repo#*/}"

    docker tag "$repo" "$tag"
    docker push "$tag"
    docker rmi "$tag"

    image=${tag%:*}
    layers="$(gcloud container images list-tags "$image" --filter 'NOT tags:*' --format='get(digest)' | tail -n +2)"
    for layer in $layers; do
        # Delete old image layers
        gcloud container images delete "${image}@${layer}" --quiet
    done
done