/lib/live/config/0040-sudo is in open-infrastructure-system-config 20161101-lts1-2.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 | #!/bin/sh
## live-config(7) - System Configuration Components
## Copyright (C) 2006-2015 Daniel Baumann <mail@daniel-baumann.ch>
##
## This program comes with ABSOLUTELY NO WARRANTY; for details see COPYING.
## This is free software, and you are welcome to redistribute it
## under certain conditions; see COPYING for details.
#set -e
Cmdline ()
{
	# Reading kernel command line
	for _PARAMETER in ${LIVE_CONFIG_CMDLINE}
	do
		case "${_PARAMETER}" in
			live-config.noroot|noroot)
				LIVE_CONFIG_NOROOT="true"
				;;
			live-config.username=*|username=*)
				LIVE_USERNAME="${_PARAMETER#*username=}"
				;;
		esac
	done
}
Init ()
{
	# Disable root access, no matter what mechanism
	case "${LIVE_CONFIG_NOROOT}" in
		true)
			exit 0
			;;
	esac
	# Checking if package is installed or already configured
	if [ ! -e /var/lib/dpkg/info/sudo.list ] || \
	   [ -e /var/lib/live/config/sudo ]
	then
		exit 0
	fi
	echo -n " sudo"
}
Config ()
{
	# Skip sudo configuration if username is root
	case "${LIVE_USERNAME}" in
		root)
			exit 0
			;;
	esac
	# Checking if package is already configured differently
	if grep -qs "^${LIVE_USERNAME}" /etc/sudoers.d/live
	then
		exit 0
	fi
	echo "${LIVE_USERNAME} ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers.d/live
	chmod 0440 /etc/sudoers.d/live
	sudo -u "${LIVE_USERNAME}" sh -c "echo 'SU_TO_ROOT_SU=sudo' >> /home/${LIVE_USERNAME}/.su-to-rootrc"
	if [ -x /usr/bin/gconftool-2 ]
	then
		sudo -u "${LIVE_USERNAME}" gconftool-2 -s -t bool /apps/gksu/sudo-mode true
		sudo -u "${LIVE_USERNAME}" gconftool-2 -s -t bool /apps/gksu/display-no-pass-info false
	fi
	sudo -u "${LIVE_USERNAME}" sh -c "umask 0077 && mkdir -p /home/${LIVE_USERNAME}/.kde/share/config && cat > /home/${LIVE_USERNAME}/.kde/share/config/kdesurc" << EOF
[super-user-command]
super-user-command=sudo
EOF
	if [ -e /usr/share/apps/konsole/sumc.desktop ]
	then
		sudo -u "${LIVE_USERNAME}" sh -c "umask 0077 && mkdir -p /home/${LIVE_USERNAME}/.kde/share/apps/konsole && sed -e's/Exec=su.*$/Exec=sudo mc -c/' /usr/share/apps/konsole/sumc.desktop > /home/${LIVE_USERNAME}/.kde/share/apps/konsole/sumc.desktop"
	fi
	if [ -e /usr/share/apps/konsole/su.desktop ]
	then
		sudo -u "${LIVE_USERNAME}" sh -c "umask 0077 && mkdir -p /home/${LIVE_USERNAME}/.kde/share/apps/konsole && sed -e's/Exec=su.*$/Exec=sudo -i/' /usr/share/apps/konsole/su.desktop > /home/${LIVE_USERNAME}/.kde/share/apps/konsole/su.desktop"
	fi
	# Creating state file
	touch /var/lib/live/config/sudo
}
Cmdline
Init
Config
 |