#!/bin/bash -ex
#
# email-relay-dash-to-plus-install (Ubuntu 16.04 LTS xenial, 18.04 LTS bionic)
#
# https://github.com/alestic/alestic-email-relay-dash-to-plus
#
domain="${1-example.com}"
host="${2-email-relay-dash-to-plus}"
waithandle="$3"
email="$4"

if [ -n "$waithandle" ]; then
    # Let CloudFormation know if this instance fails
    trap '
        instance_id=$(curl -s http://instance-data/latest/meta-data/instance-id)
        curl -X PUT -H '"'"'Content-Type:'"'"' --data-binary '"'"'{"Status":"FAILURE","Reason":"Configuration Failed","UniqueId":"'$instance_id'","Data":"Error during instance initialization. See /var/log/user-data.log"}'"'"' "$waithandle"
    ' ERR
fi

echo "INSTANCE CONFIGURATION START"

echo "$0"

hostname $host.$domain
echo "127.0.1.2 $host.$domain $host" >> /etc/hosts
echo $host.$domain > /etc/hostname
echo $host.$domain > /etc/mailname
service rsyslog restart

# Avoid hanging on dist-upgrade terminal input in Ubuntu 18.04
tmpfile=$(mktemp /tmp/encoding-XXXXXX.conf)
echo "console-setup   console-setup/charmap47 select  UTF-8" > $tmpfile
debconf-set-selections $tmpfile
rm $tmpfile

# And another to prevent hanging on console input
apt-mark hold grub-legacy-ec2

apt-get update
apt-get dist-upgrade -y
DEBIAN_FRONTEND=noninteractive apt-get install -y postfix postfix-pcre

if [ -n "$email" ]; then
    echo "root: $email" >> /etc/aliases
    newaliases
fi

# Reject addresses without '-' to prevent infinite loop with Google.
echo '!'"/^([^-]+)-(.*)@$domain\$/ REJECT" > /etc/postfix/recipients-pcre
postconf -e "smtpd_recipient_restrictions = check_recipient_access pcre:/etc/postfix/recipients-pcre reject_unauth_destination"

# Rewrite USERNAME-ANYTHING@DOMAIN to USERNAME+ANYTHING@DOMAIN
echo "/^([^-]+)-(.*)@$domain\$/ \$1+\$2@$domain" \
    > /etc/postfix/valiases-pcre
postconf -e "virtual_alias_maps = pcre:/etc/postfix/valiases-pcre"

postconf -e "myhostname = $host.$domain"
postconf -e "relay_domains = $domain"
postconf -e "mydestination = $host.$domain, localhost.$domain, localhost"

# Increase message size limit from default ~10MB to 25MB (GMail limit)
postconf -e "message_size_limit = 26214400"

/etc/init.d/postfix reload

# Let CloudFormation know this instance is ready.
if [ -n "$waithandle" ]; then
    instance_id=$(curl -s http://instance-data/latest/meta-data/instance-id)
    curl -X PUT -H 'Content-Type:' --data-binary '{"Status":"SUCCESS","Reason":"Configuration Complete","UniqueId":"'$instance_id'","Data":"Instance has completed configuration."}' "$waithandle"
fi

echo "INSTANCE CONFIGURATION COMPLETE"