#'EOF' in quotes is needed to disable expansion
cat <<'EOF' > /usr/local/bin/get-ip-address
/sbin/ifconfig | grep "inet addr" | grep -v "127.0.0.1" | awk '{ print $2 }' | awk -F: '{ print $2 }'
EOF
cat <<'EOF' > /etc/network/if-up.d/show-ip-address
#!/bin/sh
if [ "$METHOD" = loopback ]; then
    exit 0
fi
# Only run from ifup.
if [ "$MODE" != start ]; then
    exit 0
fi

cp /etc/issue-standard /etc/issue
echo "IP Address: " >> /etc/issue
/usr/local/bin/get-ip-address >> /etc/issue
echo "" >> /etc/issue
EOF
cp /etc/issue /etc/issue-standard
chmod +x /usr/local/bin/get-ip-address
chmod +x /etc/network/if-up.d/show-ip-address