simulate useradd for alpine

useradd.sh

#!/bin/sh
set -e
while test $# -gt 0
do
    case "$1" in
        -m)
            # create homedir
            shift 1 ;;
        -d)
            _home="$2"
            shift 2 ;;
        -s)
            _shell="$2"
            shift 2 ;;
        -p)
            _password="$2"
            shift 2 ;;
        *)
            _username="$1"
            break ;;
    esac
done

[[ -z "${_home}" ]] && echo "Missing home" && exit 1
[[ -z "${_shell}" ]] && echo "Missing shell" && exit 1
[[ -z "${_password}" ]] && echo "Missing password" && exit 1
[[ -z "${_username}" ]] && echo "Missing username" && exit 1

adduser -h ${_home} -s ${_shell} -D ${_username}
# change password
password=$(echo "${_password}" | mkpasswd) && echo "kitchen:${password}" | chpasswd

exit 0