enable_dhcp.sh

#!/bin/bash
#
# Re-enable the default DHCP-based NetworkManager support. Use to revert the
# static IP configuration performed by the enable_static_ip.sh script.
#
# Example usage:
# enable_dhcp.sh
#
# WARNING: Do not use this script if there is a custom network configuration
# set up in /etc/network/interfaces as it will be overwritten.

set -e

if [[ ${UID} -ne 0 ]]; then
	echo "This script must be run as root!"
	exit 1
fi

if grep -qi kuiper "/etc/os-release"; then
	cat <<-EOF > /etc/dhcpcd.conf
		hostname
	EOF
	systemctl daemon-reload
	systemctl restart dhcpcd.service
else
	echo "Re-enabling DHCP via NetworkManager for all network interfaces"

	cat <<-EOF > /etc/network/interfaces
		# interfaces(5) file used by ifup(8) and ifdown(8)
		# Include files from /etc/network/interfaces.d:
		source-directory /etc/network/interfaces.d
	EOF

	# enable DHCP via NetworkManager (assumes the config file hasn't been touched much)
	sed -i 's/^managed=true/managed=false/' /etc/NetworkManager/NetworkManager.conf

	service network-manager restart
fi