docker-mailserver/target/bin/generate-dkim-config

#!/bin/sh

touch /tmp/vhost.tmp

# if no keysize is provided, 2048 is default.
keysize=${1:-2048}

# Getting domains from mail accounts
if [ -f /tmp/docker-mailserver/postfix-accounts.cf ]; then
  while IFS=$'|' read login pass
  do
    domain=$(echo ${login} | cut -d @ -f2)
    echo ${domain} >> /tmp/vhost.tmp
  done < /tmp/docker-mailserver/postfix-accounts.cf
fi

# Getting domains from mail aliases
if [ -f /tmp/docker-mailserver/postfix-virtual.cf ]; then
  while read from to
  do
    # Setting variables for better readability
    uname=$(echo ${from} | cut -d @ -f1)
    domain=$(echo ${from} | cut -d @ -f2)
    # if they are equal it means the line looks like: "user1     other@domain.tld"
    test "$uname" != "$domain" && echo ${domain} >> /tmp/vhost.tmp
  done < /tmp/docker-mailserver/postfix-virtual.cf
fi

# Keeping unique entries
if [ -f /tmp/vhost.tmp ]; then
  cat /tmp/vhost.tmp | sort | uniq > /tmp/vhost && rm /tmp/vhost.tmp
fi

# Exit if no entries found
if [ ! -f /tmp/vhost ]; then
	echo "No entries found, no keys to make"
	exit 0
fi

grep -vE '^(\s*$|#)' /tmp/vhost | while read domainname; do
  mkdir -p /tmp/docker-mailserver/opendkim/keys/$domainname

  if [ ! -f "/tmp/docker-mailserver/opendkim/keys/$domainname/mail.private" ]; then
    echo "Creating DKIM private key /tmp/docker-mailserver/opendkim/keys/$domainname/mail.private"
    opendkim-genkey --bits=$keysize --subdomains --domain=$domainname --selector=mail -D /tmp/docker-mailserver/opendkim/keys/$domainname
  fi

  # Write to KeyTable if necessary
  keytableentry="mail._domainkey.$domainname $domainname:mail:/etc/opendkim/keys/$domainname/mail.private"
  if [ ! -f "/tmp/docker-mailserver/opendkim/KeyTable" ]; then
    echo "Creating DKIM KeyTable"
    echo $keytableentry > /tmp/docker-mailserver/opendkim/KeyTable
  else
    if ! grep -q "$keytableentry" "/tmp/docker-mailserver/opendkim/KeyTable" ; then
        echo $keytableentry >> /tmp/docker-mailserver/opendkim/KeyTable
    fi
  fi

  # Write to SigningTable if necessary
  signingtableentry="*@$domainname mail._domainkey.$domainname"
  if [ ! -f "/tmp/docker-mailserver/opendkim/SigningTable" ]; then
    echo "Creating DKIM SigningTable"
    echo "*@$domainname mail._domainkey.$domainname" > /tmp/docker-mailserver/opendkim/SigningTable
  else
    if ! grep -q "$signingtableentry" "/tmp/docker-mailserver/opendkim/SigningTable" ; then
      echo $signingtableentry >> /tmp/docker-mailserver/opendkim/SigningTable
    fi
  fi
done

# Creates TrustedHosts if missing
if [ -d "/tmp/docker-mailserver/opendkim" ] && [ ! -f "/tmp/docker-mailserver/opendkim/TrustedHosts" ]; then
  echo "Creating DKIM TrustedHosts";
  echo "127.0.0.1" > /tmp/docker-mailserver/opendkim/TrustedHosts
  echo "localhost" >> /tmp/docker-mailserver/opendkim/TrustedHosts
fi