#!/bin/sh -euf

usage() (
	echo "upgrade-containers.sh"
	echo
	echo "Upgrade currently running LXC containers."
	echo "Uses apt-get for Debian and apk for Alpine."
	echo
)

upgrade_container() (
	NAME="$1"

	RELEASE_FILE="/var/lib/lxc/$NAME/rootfs/etc/os-release"

	if grep -q "ID=debian" "$RELEASE_FILE"; then
		lxc-attach -n "$NAME" -- apt-get update
		lxc-attach -n "$NAME" -- apt-get upgrade -y
	elif grep -q "ID=alpine" "$RELEASE_FILE"; then
		lxc-attach -n "$NAME" -- apk update
		lxc-attach -n "$NAME" -- apk upgrade
	fi
)

upgrade_running_containers() (
	for CONTAINER in $(lxc-ls --running); do
		upgrade_container "$CONTAINER"
	done
)

case "${1:-run}" in
	"help")	usage;;
	"run")	upgrade_running_containers;;
esac