docker-mailserver/target/bin/updatemailuser

#! /bin/bash

# ? This is done to ignore the message "Make sure not to read and write
# ? the same file in the same pipeline", which is a result of ${DATABASE}
# ? being used below. (This disables the message file-wide.)
# shellcheck disable=SC2094

# shellcheck source=../scripts/helper-functions.sh
. /usr/local/bin/helper-functions.sh

DATABASE=${DATABASE:-/tmp/docker-mailserver/postfix-accounts.cf}

USER="${1}"
shift
PASSWD="${*}"

function usage  {	echo "Usage: updatemailuser <user@domain.tld> [password]" ; }

[[ -z ${USER} ]] && { usage ; errex "no username specified" ; }

if [[ -z ${PASSWD} ]]
then
  read -r -s -p "Enter Password: " PASSWD
  echo
  [[ -z ${PASSWD} ]] && errex "Password must not be empty"
fi

HASH="$(doveadm pw -s SHA512-CRYPT -u "${USER}" -p "${PASSWD}")"

touch "${DATABASE}"
create_lock # Protect config file with lock to avoid race conditions
grep -qi "^$(escape "${USER}")|" "${DATABASE}" 2>/dev/null || errex "User \"${USER}\" does not exist"
sed -i "s ^""${USER}""|.* ""${USER}""|""${HASH}"" " "${DATABASE}"