alpine-linux-headless-bootstrap/sample_unattended.sh

#!/bin/sh

# SPDX-FileCopyrightText: Copyright 2022-2023, macmpi
# SPDX-License-Identifier: MIT

## collection of few code snippets as sample unnatteded actions some may find usefull

## will run encapusated within headless_unattended OpenRC service

# To prevent headless bootstrap script from starting sshd
# only keep a single starting # on the line below
##NO_SSH

# Enable stdout and errors redirection to console if desired (service won't show messages)
# exec 1>/dev/console 2>&1

# shellcheck disable=SC2142  # known special case
alias _logger='logger -st ${0##*/}'


## Obvious one; reminder: is run as background service
_logger "hello world !!"
sleep 60
_logger "Finished script"
########################################################


## This snippet removes apkovl file on volume after initial boot
# grab used ovl filename from dmesg
ovl="$( dmesg | grep -o 'Loading user settings from .*:' | awk '{print $5}' | sed 's/:.*$//' )"
if [ -f "${ovl}" ]; then
	ovlpath="$( dirname "$ovl" )"
else
	# search path again as mountpoint have been changed later in the boot process...
	ovl="$( basename "${ovl}" )"
	ovlpath=$( find /media -maxdepth 2 -type d -path '*/.*' -prune -o -type f -name "${ovl}" -exec dirname {} \; | head -1 )
	ovl="${ovlpath}/${ovl}"
fi

# also works in case volume is mounted read-only
grep -q "${ovlpath}.*[[:space:]]ro[[:space:],]" /proc/mounts; RO=$?
[ "$RO" -eq "0" ] && mount -o remount,rw "${ovlpath}"
rm -f "${ovl}"
[ "$RO" -eq "0" ] && mount -o remount,ro "${ovlpath}"

########################################################


## This snippet configures Minimal diskless environment
# note: with INTERFACESOPTS=none, no networking will be setup so it won't work after reboot!
# Change it or run setup-interfaces in interractive mode afterwards (and lbu commit -d thenafter)

_logger "Setting-up minimal environment"

cat <<-EOF > /tmp/ANSWERFILE
	# base answer file for setup-alpine script

	# Do not set keyboard layout
	KEYMAPOPTS=none

	# Keep hostname
	HOSTNAMEOPTS="$(hostname)"

	# Set device manager to mdev
	DEVDOPTS=mdev

	# Contents of /etc/network/interfaces
	INTERFACESOPTS=none

	# Set Public nameserver
	DNSOPTS="-n 208.67.222.222"

	# Set timezone to UTC
	TIMEZONEOPTS="UTC"

	# set http/ftp proxy
	PROXYOPTS=none

	# Add first mirror (CDN)
	APKREPOSOPTS="-1"

	# Do not create any user
	USEROPTS=none

	# No Openssh
	SSHDOPTS=none

	# Use openntpd
	NTPOPTS="chrony"

	# No disk install (diskless)
	DISKOPTS=none

	# Setup storage for diskless (find boot directory in /media/xxxx/apk/.boot_repository)
	LBUOPTS="$( find /media -maxdepth 3 -type d -path '*/.*' -prune -o -type f -name '.boot_repository' -exec dirname {} \; | head -1 | xargs dirname )"
	APKCACHEOPTS="\$LBUOPTS/cache"

	EOF

# trick setup-alpine to pretend existing SSH connection
# and therefore keep (do not reset) network interfaces while running in background
SSH_CONNECTION="FAKE" setup-alpine -ef /tmp/ANSWERFILE
lbu commit -d

########################################################


_logger "Finished unattended script"