Create Posteio container network

create_posteio_network.sh

#!/bin/bash

docker network create posteio &>/dev/null
id=$(docker network inspect --format "{{.ID}}" posteio 2>/dev/null | cut -c1-12)
[[ -z "$id" ]] && exit 1
MASQUERADE=$(iptables -S -t nat | egrep "POSTROUTING.*br-$id.*MASQUERADE")
[[ -z "$MASQUERADE" ]] && exit 0
source /etc/environment
[[ -z "$POSTEIO_PUBLIC_IPV4" ]] && exit 1
iptables -t nat $(echo "$MASQUERADE" | sed -n "s/^-A/-I/;s/MASQUERADE/SNAT --to-source $POSTEIO_PUBLIC_IPV4/p")
iptables -t nat $(echo "$MASQUERADE" | sed -n "s/^-A/-D/p")