Add old WW3 keygen to examples

Signed-off-by: jcsiadal <jeremy.c.siadal@intel.com>

etc/examples/ssh_config.sh

@@ -0,0 +1,33 @@
+#!/bin/sh
+##
+## Copyright (c) 2001-2003 Gregory M. Kurtzer
+##
+## Copyright (c) 2003-2012, The Regents of the University of California,
+## through Lawrence Berkeley National Laboratory (subject to receipt of any
+## required approvals from the U.S. Dept. of Energy).  All rights reserved.
+##
+## Copied from https://github.com/warewulf/warewulf3/blob/master/cluster/bin/cluster-env
+
+## Automatically configure SSH keys for a user on login
+## Copy this file to /etc/profile.d
+
+_UID=`id -u`
+
+if [ $_UID -lt 500 -a $_UID -ne 0 ]; then
+    exit
+fi
+
+
+if [ ! -f "$HOME/.ssh/config" -a ! -f "$HOME/.ssh/cluster" ]; then
+    echo "Configuring SSH for cluster access"
+    install -d -m 700 $HOME/.ssh
+    ssh-keygen -t rsa -f $HOME/.ssh/cluster -N '' -C "Warewulf Cluster key" > /dev/null 2>&1
+    cat $HOME/.ssh/cluster.pub >> $HOME/.ssh/authorized_keys
+    chmod 0600 $HOME/.ssh/authorized_keys
+
+    echo "# Added by Warewulf  `date +%Y-%m-%d 2>/dev/null`" >> $HOME/.ssh/config
+    echo "Host *" >> $HOME/.ssh/config
+    echo "   IdentityFile ~/.ssh/cluster" >> $HOME/.ssh/config
+    echo "   StrictHostKeyChecking=no" >> $HOME/.ssh/config
+    chmod 0600 $HOME/.ssh/config
+fi