gns3-docker-images/hub_push

#!/bin/sh
#
# push repositories to DockerHub
#
# Requires curl and docker
#

set -e

HUB_USER=$(docker info 2>/dev/null | sed -n 's/^Username:[[:space:]]*//p')
if [ -z "$HUB_USER" ]; then
	echo 'Use "docker login" to login into DockerHub.' >&2
	exit 1
fi

hub_update() {
	local_repo=$1
	hub_repo=$HUB_USER/${local_repo##*/}

	# get local digest
	local_digest=$(docker inspect "$local_repo" --format '{{.Id}}' 2>/dev/null)
	[ -z "$local_digest" ] && return

	# get remote digest
	token=$(curl --silent "https://auth.docker.io/token?scope=repository:${hub_repo}:pull&service=registry.docker.io" | \
		tr '\r\n' '  ' | \
		sed -n 's/^.*"token": *"\([^"]*\)".*/\1/p')
	hub_digest=$(curl --silent \
		--header 'Accept: application/vnd.docker.distribution.manifest.v2+json' \
		--header "Authorization: Bearer $token" \
		"https://registry-1.docker.io/v2/${hub_repo}/manifests/latest" | \
		tr '\r\n' '  ' | \
		sed -n 's/^.*"config": *{[^}]*"digest": *"\([^"]*\)".*/\1/p')

	# push repository, if digest differs
	if [ "$local_digest" \!= "$hub_digest" ]; then
		echo
		echo "*** $hub_repo"
		echo
		[ "$local_repo" = "$hub_repo" ] || \
			docker tag "$local_repo" "$hub_repo"
		docker push "$hub_repo"
		[ "$local_repo" = "$hub_repo" ] || \
			docker rmi "$hub_repo" > /dev/null
	fi
}

if [ $# -gt 0 ]; then
	# push repos given on command line
	for repo in "$@"; do
		hub_update "$repo"
	done
else
	# push (almost) all repos
	images=$(sed -e '/^[[:space:]]*$/d' -e '/^[[:space:]]*#/d' hub_images)
	for repo in $images; do
		hub_update "$repo"
	done
fi