#!/bin/sh

#
# entrypoint script for postfix smarthost mail relay
#

convertCase () {
    printf "%s" "$1" | tr "[:lower:]" "[:upper:]"
}

if [ -f "/etc/postfix/main.cf.override" ]; then
    # use provided configuration file
    printf "\nAppending provided MAIN configuration... "
    cat /etc/postfix/main.cf.override >> /etc/postfix/main.cf
    \rm -f /tmp/main.cf.insert
else
    # process auto-setup
    printf "\nVerifying environment variables... "

    # check for missing environment variable values
    if [ -z "$SMARTHOST" ]; then
        printf "\nYou must specify the hostname or IP address of a smarthost where mail should be relayed.\n\n"
        exit 1
    fi
    if [ -z "$SMARTHOST_USERNAME" ]; then
        printf "\nYou must provide a username for smarthost authentication.\n\n"
        exit 1
    fi
    if [ -z "$SMARTHOST_PASSWORD" ]; then
        printf "\nYou must provide a password for smarthost authentication.\n\n"
        exit 1
    fi

    # set failsafes
    [ -z "$SMARTHOST_PORT" ] && SMARTHOST_PORT=587
    [ -z "$LOCAL_HOSTNAME" ] && LOCAL_HOSTNAME="$(uname -n)"
    [ -z "$LOCAL_DOMAINNAME" ] && LOCAL_DOMAINNAME="${LOCAL_HOSTNAME#*.}"

    printf "done\n"
    printf "updating configuration files... "

    # update main.cf
    sed -i "s/{LOCAL_HOSTNAME}/${LOCAL_HOSTNAME}/" /tmp/main.cf.insert
    sed -i "s/{LOCAL_DOMAINNAME}/${LOCAL_DOMAINNAME}/" /tmp/main.cf.insert
    sed -i "s/{SMARTHOST}/${SMARTHOST}/" /tmp/main.cf.insert
    sed -i "s/{SMARTHOST_PORT}/${SMARTHOST_PORT}/" /tmp/main.cf.insert
    sed -i "s/{SMARTHOST_USERNAME}/${SMARTHOST_USERNAME}/" /tmp/main.cf.insert
    sed -i "s/{SMARTHOST_PASSWORD}/${SMARTHOST_PASSWORD}/" /tmp/main.cf.insert

    LOCAL_ENCRYPTION="$(convertCase "$LOCAL_ENCRYPTION")"
    case "$LOCAL_ENCRYPTION" in
        OPT*)
            sed -i 's/{LOCAL_ENCRYPTION}/may/' /tmp/main.cf.insert
            sed -i 's/#smtpd_/smtpd_/g' /tmp/main.cf.insert
            ;;
        TRUE)
            sed -i 's/{LOCAL_ENCRYPTION}/encrypt/' /tmp/main.cf.insert
            sed -i 's/#smtpd_/smtpd_/g' /tmp/main.cf.insert
            ;;
        *)
            sed -i 's/{LOCAL_ENCRYPTION}//' /tmp/main.cf.insert
            ;;
    esac

    SMARTHOST_ENCRYPTION="$(convertCase "$SMARTHOST_ENCRYPTION")"
    case "$SMARTHOST_ENCRYPTION" in
        OPT*)
            sed -i 's/{SMARTHOST_ENCRYPTION}/may/' /tmp/main.cf.insert
            ;;
        TRUE)
            sed -i 's/{SMARTHOST_ENCRYPTION}/secure/' /tmp/main.cf.insert
            ;;
        *)
            sed -i 's/{SMARTHOST_ENCRYPTION}/none/' /tmp/main.cf.insert
            ;;
    esac

    # append configuration and remove temp file
    cat /tmp/main.cf.insert >> /etc/postfix/main.cf
    \rm -f /tmp/main.cf.insert
fi
printf "done\n"

if [ -f "/etc/postfix/master.cf.override" ]; then
    # use provided configuration file
    printf "\nUsing provided MASTER configuration... "
    \cp --force /etc/postfix/master.cf.override /etc/postfix/master.cf
else
    # update master.cf
    sed -i 's/#tlsproxy/tlsproxy/' /etc/postfix/master.cf
fi
printf "done\n"

printf "container setup complete!\n"

# run CMD passed to this container
printf "\nExecuting: %s\n" "$*"
exec "$@"

exit 0
#EOF