bash: latest Docker semver tag for image

get-latest-alpine.sh

#!/usr/bin/env bash
die() { echo "${1:-hurts}" >&2; exit "${2:-1}"; }

hash jq   2>/dev/null || die "missing dep: jq"

curl -s https://registry.hub.docker.com/v1/repositories/alpine/tags \
    | jq -r '.[].name' \
    | grep -E '^[0-9]+\.[0-9]+(\..+)?$' \
    | sort -t. -k1,1n -k2,2n -k3,3n \
    | tail -n1