Autoconf of /etc/krb5.conf. Replace default value with your value.

kerberos-autoconf.sh

#!/bin/bash
if [ "$1" == "-h" ]; then
  echo "Usage:	`basename $0` Autoconf of /etc/krb5.conf. Replace default value with your value."
  echo " -r <REALM> (Your Realm. Ex: FOO)"
  echo " -k <KDC> (The KDC. Ex: DC1)"
  echo " -f <FQDN> (The FQDN of your domain. Ex:  FOO.LOCAL)"
  exit 0
fi
while getopts r:k:f: option
do
 case "${option}"
 in
 r) REALM=${OPTARG};;
 k) KDC=${OPTARG};;
 f) FQDN=${OPTARG};;
 esac
done

KRB5CONF="[libdefaults] \n
\tdefault_realm = FOO.LOCAL \n
\tkdc_timesync = 1 \n
\tccache_type = 4 \n
\tforwardable = true \n
\tproxiable = true \n
\tv4_instance_resolve = false \n
\tv4_name_convert = { \n
\thost = { \n
\t\trcmd = host \n
\t\tftp = ftp \n
\t\t} \n
\tplain = { \n
\t\tsomething = something-else \n
\t\t} \n
\t} \n
\tfcc-mit-ticketflags = true \n
 \n
[realms] \n
FOO = { \n
kdc = DC1.foo.local:88 \n
admin_server = DC1.foo.local \n
default_domain = foo.local \n
} \n
[domain_realm] \n
.foo.local = FOO.LOCAL \n
foo.local = FOO.LOCAL \n
[login] \n
krb4_convert = true \n
krb4_get_tickets = false"

# Keep the case
REALM=$(echo $REALM | tr '[:lower:]' '[:upper:]')
FQDN_LOWERCASE=$(echo $FQDN | tr '[:upper:]' '[:lower:]')
FQDN_UPPERCASE=$(echo $FQDN | tr '[:lower:]' '[:upper:]')
KDC = $k

echo "[*] Using $REALM as REALM"
echo "[*] Using $FQDN as FQDN"
echo "[*] Using $KDC as KDC"
echo "[*] Printing conf ..."
echo ""

NEWKRB5CONF=$(echo $KRB5CONF |sed "s/DC1/$KDC/g" | sed "s/FOO /$REALM /g" | sed "s/FOO.LOCAL/$FQDN_UPPERCASE/g"  |  sed "s/foo.local/$FQDN_LOWERCASE/g" )
echo -e $NEWKRB5CONF

echo ""
echo -n "Want to copy the content to /etc/krb5.conf ? (y/n): "
read v
if [[ $v == "y"  ||  $v == "Y" ]]; then
 # careful here, missing a unique backup of the orignal krb5.conf file (if you run the script 2 times,  you will erase the backup /o\)
	cp /etc/krb5.conf /etc/krb5.conf.bak
	echo "Current configuration file backup to /etc/krb5.conf.bak..."
	echo -e $NEWKRB5CONF > /etc/krb5.conf
	echo "New kerberos client configuration file created in /etc/krb5.conf !"
else
	echo "Good bye !"
	exit 0
fi