Merge pull request #19 from macmpi/dev

version 1.0

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2022 macmpi
+Copyright (c) 2022-2023 macmpi
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -4,45 +4,46 @@
 However, in many cases one might want to deploy a headless system that is only available through a network connection (ethernet, wifi or as USB ethernet gadget).
 
 This repo provides an **overlay file** to initially bootstrap[^1] a headless system (leveraging Alpine distro's `initramfs` feature): it starts a ssh server to log-into from another Computer, so that actual install on fresh system (or rescue on existing disk-based system) can then be performed remotely.\
-An optional script may be launched at startup, to perform automated actions/setup.
+An optional script may also be launched during that same initial bootstrap, to perform fully automated setup.
 
 
 ## Setup procedure:
 Please follow [Alpine Linux Wiki](https://wiki.alpinelinux.org/wiki/Installation#Installation_Overview) to download & create installation media for the target platform.\
 Tools provided here can be used on any plaform for any install modes (diskless, data disk, system disk).
 
-Just add [**headless.apkovl.tar.gz**](https://is.gd/apkovl_master)[^2] overlay file at the root of Alpine Linux boot media (or onto any custom side-media) and boot-up the system.\
+Just add [**headless.apkovl.tar.gz**](https://is.gd/apkovl_master)[^2] overlay file *as-is* at the root of Alpine Linux boot media (or onto any custom side-media) and boot-up the system.\
-With default network interface definitions (and [SSID/pass file](#extra-configuration) if using wifi), system can then be remotely accessed with: `ssh root@<IP>`\
+With default DCHP-based network interface definitions (and [SSID/pass file](#extra-configuration) if using wifi), system can then be remotely accessed with: `ssh root@<IP>`\
 (system IP address may be determined with any IP scanning tools such as `nmap`).
 
-As with Alpine Linux initial bring-up, `root` account has no password initially (change that during setup!).\
+As with Alpine Linux initial bring-up, `root` account has no password initially (change that during target setup!).\
 From there, actual system install can be performed as usual with `setup-alpine` for instance (check [wiki](https://wiki.alpinelinux.org/wiki/Alpine_setup_scripts#setup-alpine) for details).
 
 ## Extra configuration:
 Extra files may be added next to `headless.apkovl.tar.gz` to customise boostrapping configuration (check sample files):
 - `wpa_supplicant.conf`[^3] (*mandatory for wifi usecase*): define wifi SSID & password.
+- `unattended.sh`[^3] (*optional*): provide a deployment script to automate setup & customizations during initial bootstrap.
 - `interfaces`[^3] (*optional*): define network interfaces at will, if defaults DCHP-based are not suitable.
 - `authorized_keys` (*optional*): provide client's public SSH key to secure `root` ssh login.
 - `ssh_host_*_key*` (*optional*): provide server's custom ssh keys to be injected (may be stored), instead of using bundled ones[^2] (not stored). Providing an empty key file will trigger new keys generation (ssh server may take longer to start).
-- `unattended.sh`[^3] (*optional*): create custom automated deployment script to further tune & extend actual setup (backgrounded).
 
 
-**Goody:** seamless USB-ethernet gadget boostrapping (PiZero for instance):\
+**Goody:** seamless USB-serial & USB-ethernet gadget mode (PiZero for instance):\
-On supporting Pi devices, just add `dtoverlay=dwc2` in `usercfg.txt` (or `config.txt`), and plug USB cable into Computer port.\
+On supporting Pi devices, just add `dtoverlay=dwc2,dr_mode=peripheral` in `usercfg.txt` (or `config.txt`), and plug USB cable into host Computer port.\
-With Computer set-up to share networking with USB interface as 10.42.0.1 gateway, one can log into device from Computer with: `ssh root@10.42.0.2`
+Serial terminal can then be connected-to from host Computer (xon/xoff flow control: e.g. on Linux with `cu -l ttyACM0`).\
+Alternatively, with host Computer set-up to share networking with USB interface as 10.42.0.1 gateway, one can log into device from host with: `ssh root@10.42.0.2`.
 
-Main execution steps are logged in `/var/log/messages`.
+Main execution steps are logged: `cat /var/log/messages | grep headless`.
 
 [^1]: Initial boot fully preserves system's original state (config files & installed packages): a fresh system will therefore come-up as unconfigured.
 
-[^2]: About bundled ssh keys: this overlay is meant to **quickly bootstrap** system in order to then proceed with proper install; therefore it purposely embeds [some ssh keys](https://github.com/macmpi/alpine-linux-headless-bootstrap/tree/main/overlay/etc/ssh) so that bootstrapping is as fast as possible. Those temporary keys are moved in RAM /tmp: they will **not be stored/reused** once actual system install is performed (whether or not ssh server is installed in final setup).
+[^2]: About bundled ssh keys: this overlay is meant to **quickly bootstrap** system in order to then proceed with proper install; therefore it purposely embeds [some ssh keys](https://github.com/macmpi/alpine-linux-headless-bootstrap/tree/main/overlay/tmp/.trash) so that bootstrapping is as fast as possible. Those temporary keys are moved in RAM /tmp: they will **not be stored/reused** once actual system install is performed (whether or not ssh server is installed in final setup).
 
 [^3]: These files are linux text files: Windows/macOS users need to use text editors supporting linux text line-ending (such as [notepad++](https://notepad-plus-plus.org/), BBEdit or any similar).
 
 
 ## Want to tweak more ?
 This repository may be forked/cloned/downloaded.\
-Main script file is [`headless.start`](https://github.com/macmpi/alpine-linux-headless-bootstrap/blob/main/overlay/etc/local.d/headless.start).\
+Main script file is [`headless.start`](https://github.com/macmpi/alpine-linux-headless-bootstrap/tree/main/overlay/usr/local/bin/headless_bootstrap).\
 Execute `./make.sh` to rebuild `headless.apkovl.tar.gz` after changes.
 
 

make.sh

@@ -1,8 +1,30 @@
-#!/bin/sh
+#!/bin/busybox sh
 
-# Copyright 2022 - 2023, macmpi
+# SPDX-FileCopyrightText: Copyright 2022-2023, macmpi
 # SPDX-License-Identifier: MIT
 
-chmod 600 overlay/etc/ssh/ssh_host_*_key
+
-chmod +x overlay/etc/local.d/headless.start
+command -v doas > /dev/null || alias doas="/usr/bin/sudo"
-tar czvf headless.apkovl.tar.gz -C overlay etc --owner=0 --group=0
+
+build_path="$(mktemp -d)"
+if [ -n "$build_path" ]; then
+	cp -r overlay "$build_path"/.
+	find "$build_path"/overlay/ -exec touch -md "$(date '+%F 00:00:00')" {} \;
+
+	# setting owner/groups for runtime (won't affect mtime)
+	find "$build_path"/overlay/etc -type d -exec chmod 755 {} \;
+	chmod +x "$build_path"/overlay/etc/init.d/*
+	find "$build_path"/overlay/usr -type d -exec chmod 755 {} \;
+	chmod +x "$build_path"/overlay/usr/local/bin/*
+	chmod 777 "$build_path"/overlay/tmp
+	chmod 700 "$build_path"/overlay/tmp/.trash
+	chmod 600 "$build_path"/overlay/tmp/.trash/ssh_host_*_key
+	doas chown -R 0:0 "$build_path"/overlay/*
+
+	doas tar -cvf "$build_path"/headless.apkovl.tar -C "$build_path"/overlay etc usr tmp
+	gzip -nk9 "$build_path"/headless.apkovl.tar && mv "$build_path"/headless.apkovl.tar.gz .
+	touch -md "$(date '+%F 00:00:00')" headless.apkovl.tar.gz
+
+	doas rm -rf "$build_path"
+fi
+

overlay/etc/init.d/headless_bootstrap

@@ -0,0 +1,12 @@
+#!/sbin/openrc-run
+
+# SPDX-FileCopyrightText: Copyright 2022-2023, macmpi
+# SPDX-License-Identifier: MIT
+
+description="Headless main boostrappring script"
+name="Headless bootstrap"
+
+command="/usr/local/bin/headless_bootstrap"
+command_background=true
+pidfile="/run/${RC_SVCNAME}.pid"
+

overlay/etc/init.d/headless_cleanup

@@ -0,0 +1,12 @@
+#!/sbin/openrc-run
+
+# SPDX-FileCopyrightText: Copyright 2022-2023, macmpi
+# SPDX-License-Identifier: MIT
+
+description="Headless cleanup script"
+name="Headless cleanup"
+
+command="/tmp/.trash/headless_cleanup"
+command_background=true
+pidfile="/run/${RC_SVCNAME}.pid"
+

overlay/etc/init.d/headless_unattended

@@ -0,0 +1,12 @@
+#!/sbin/openrc-run
+
+# SPDX-FileCopyrightText: Copyright 2022-2023, macmpi
+# SPDX-License-Identifier: MIT
+
+description="Headless unattended setup script (optional)"
+name="Headless unattended"
+
+command="/tmp/headless_unattended"
+command_background=true
+pidfile="/run/${RC_SVCNAME}.pid"
+

overlay/etc/local.d/headless.start

@@ -1,247 +0,0 @@
-#!/bin/sh
-
-# Copyright 2022 - 2023, macmpi
-# SPDX-License-Identifier: MIT
-
-VERSION="0.9"
-
-
-_apk() {
-	local cmd="$1"
-	local pkg="$2"
-
-	case $cmd in
-		add) # install only if not already present
-			if ! apk info | grep -wq "${pkg}"; then
-				apk add "$pkg" && printf "${pkg} " >> /tmp/.trash/installed
-			fi
-		;;
-		del) # delete only if previously installed
-			if grep -wq "$pkg" /tmp/.trash/installed; then
-				apk del "$pkg" && sed -i 's/\b'"${pkg}"'\b//' /tmp/.trash/installed
-			fi
-		;;
-		*)
-			echo "only add/del: wrong usage"; exit
-		;;
-	esac
-}
-
-_preserve() {
-	[ -f "$1" ] && cp "$1" "${1}.orig"
-}
-
-_restore() {
-	if [ -f "${1}.orig" ]; then
-		mv -- "${1}.orig" "${1}"
-	else
-		rm -rf "${1}"
-	fi
-}
-
-##### End of part to be duplicated into post-cleanup (do not alter!)
-
-
-# Redirect stdout and errors to console as rc.local does not log anything
-exec 1>/dev/console 2>&1
-
-logger -st ${0##*/} "Alpine Linux headless bootstrap v$VERSION by macmpi"
-
-install -dm 0700 /tmp/.trash
-
-# grab used ovl filename from dmesg
-ovl="$( dmesg | grep -o 'Loading user settings from .*:' | awk '{print $5}' | sed 's/:.*$//' )"
-ovl="$( basename "${ovl}" )"
-# search path again as mountpoint may have been changed later in the boot process...
-ovlpath=$( find /media -maxdepth 2 -type d -path '*/.*' -prune -o -type f -name "${ovl}" -exec dirname {} \; | head -1 )
-
-# Help randomness for wpa_supplicant and ssh server
-rc-service seedrng start
-
-## Setup Network interfaces
-if [ -f "${ovlpath}/wpa_supplicant.conf" ]; then
-	logger -st ${0##*/} "Configuring wifi..."
-	_apk add wpa_supplicant
-	_preserve "/etc/wpa_supplicant/wpa_supplicant.conf"
-	install -m600 "${ovlpath}/wpa_supplicant.conf" /etc/wpa_supplicant/wpa_supplicant.conf
-else
-	logger -st ${0##*/} "No wifi setup supplied !"
-fi
-
-_preserve "/etc/network/interfaces"
-if ! install -m644 "${ovlpath}/interfaces" /etc/network/interfaces; then
-	# set default interfaces if not specified by interface file on boot storage
-	logger -st ${0##*/} "No interfaces file supplied, building defaults..."
-	for dev in $(ls /sys/class/net)
-	do
-		case ${dev%%[0-9]*} in
-			lo)
-					cat <<-EOF >> /etc/network/interfaces
-					auto $dev
-					iface $dev inet loopback
-
-					EOF
-					;;
-			eth)
-					cat <<-EOF >> /etc/network/interfaces
-					auto $dev
-					iface $dev inet dhcp
-
-					EOF
-					;;
-			wlan)
-					[ -f /etc/wpa_supplicant/wpa_supplicant.conf ] && cat <<-EOF >> /etc/network/interfaces
-					auto $dev
-					iface $dev inet dhcp
-
-					EOF
-					;;
-			usb)
-					cat <<-EOF >> /etc/network/interfaces
-					auto $dev
-					iface $dev inet static
-					    address 10.42.0.2/24
-					    gateway 10.42.0.1
-
-					EOF
-
-					cat <<-EOF > /etc/resolv.conf
-					nameserver 208.67.222.222
-					nameserver 208.67.220.220
-
-					EOF
-					;;
-		esac
-	done
-fi
-
-echo "Using following network interfaces:"
-cat /etc/network/interfaces
-
-_preserve "/etc/hostname"
-echo "alpine-headless" > /etc/hostname
-hostname -F /etc/hostname
-
-grep -q "wlan" /etc/network/interfaces && \
-	[ -f /etc/wpa_supplicant/wpa_supplicant.conf ] && \
-		rc-service wpa_supplicant start
-rc-service networking start
-
-
-## Setup temporary SSH server (root login, no password)
-## We use some bundled (or optionaly provided) keys to avoid generation at startup and save time
-_apk add openssh
-_preserve "/etc/ssh/sshd_config"
-_preserve "/etc/conf.d/sshd"
-
-cat <<-EOF > /etc/ssh/sshd_config
-	PermitRootLogin yes
-	Banner /tmp/.trash/banner
-	EOF
-	
-if install -m600 "${ovlpath}/authorized_keys" /tmp/.trash/authorized_keys; then
-	logger -st ${0##*/} "Enabling public key SSH authentication..."
-	cat <<-EOF >> /etc/ssh/sshd_config
-		AuthenticationMethods publickey
-		AuthorizedKeysFile /tmp/.trash/authorized_keys
-		# relax strict mode as authorized_keys are inside /tmp
-		StrictModes no
-		EOF
-else
-	logger -st ${0##*/} "No SSH authentication."
-	cat <<-EOF >> /etc/ssh/sshd_config
-		AuthenticationMethods none
-		PermitEmptyPasswords yes
-		EOF
-fi
-
-# Banner file
-warn=""
-grep -q "${ovlpath}.*[[:space:]]ro[[:space:],]" /proc/mounts; RO=$?
-[ "$RO" -eq "0" ] && warn="(remount partition rw!)"
-
-cat <<-EOF > /tmp/.trash/banner
-
-	Alpine Linux headless bootstrap v$VERSION by macmpi
-
-You may want to delete/rename .apkovl file before reboot ${warn}:
-${ovlpath}/${ovl}
-(can be done automatically with unattended script - see sample snippet)
-
-
-	EOF
-
-# Bundled temporary keys are moved in RAM /tmp so they won't be stored
-# within permanent config later (new ones will then be generated at reboot)
-KEYGEN_STANCE="sshd_disable_keygen=yes"
-mv /etc/ssh/ssh_host_*_key* /tmp/.trash/.
-
-# Inject optional custom keys (those might be stored)
-if install -m600 "${ovlpath}"/ssh_host_*_key* /etc/ssh/; then
-	# check for empty key within injected ones: if found, generate new keys
-	if find /etc/ssh/ -maxdepth 1 -type f -name 'ssh_host_*_key*' -empty | grep -q .; then
-		rm /etc/ssh/ssh_host_*_key*
-		KEYGEN_STANCE=""
-		logger -st ${0##*/} "Will generate new SSH keys..."
-	else
-		chmod 644 /etc/ssh/ssh_host_*_key.pub
-		logger -st ${0##*/} "Using injected SSH keys..."
-	fi
-else
-	logger -st ${0##*/} "Using bundled ssh keys from RAM..."
-	cat <<-EOF >> /etc/ssh/sshd_config
-		HostKey /tmp/.trash/ssh_host_ed25519_key
-		HostKey /tmp/.trash/ssh_host_rsa_key
-		EOF
-fi
-
-echo "$KEYGEN_STANCE" >> /etc/conf.d/sshd
-rc-service sshd start
-
-## Prep for final post-cleanup
-## clears any installed packages and settings
-# copy begininng of this file to keep functions
-sed -n '/^#* End .*alter!)$/q;p' /etc/local.d/headless.start > /tmp/.trash/post-cleanup
-
-cat <<-EOF >> /tmp/.trash/post-cleanup
-
-	_tst_inet() {
-		## Tested URL redirects to github project page: is.gd shortener provides basic analytics.
-		## Analytics are public and can be checked at https://is.gd/stats.php?url=apkovl_run
-		## Privacy policy: https://is.gd/privacy.php
-		INET="failed"
-		wget -q -T 10 --spider https://is.gd/apkovl_run > /dev/null 2>&1 &&
-			INET="success"
-		logger -st ${0##*/} "Internet access: \$INET"
-	}
-
-	logger -st ${0##*/} "Cleaning-up..."
-	_restore "/etc/ssh/sshd_config"
-	_restore "/etc/conf.d/sshd"
-	_apk del openssh
-	_restore "/etc/wpa_supplicant/wpa_supplicant.conf"
-	_apk del wpa_supplicant
-	_restore "/etc/network/interfaces"
-	_restore "/etc/hostname"
-	rm /etc/modules-load.d/g_ether.conf
-	rm /etc/modprobe.d/g_ether.conf
-	rc-update del local default
-	rm /etc/local.d/headless.start
-
-	# Internet connectivity test
-	# Can be skipped by creating a 'opt-out'-named dummy file aside apkovl file
-	[ -f "${ovlpath}/opt-out" ] || _tst_inet &
-
-	# Run unattended script if available
-	if [ -f "${ovlpath}/unattended.sh" ]; then
-		install -m755 "${ovlpath}/unattended.sh" /tmp/unattended.sh
-		/tmp/unattended.sh >/dev/console 2>&1 &
-		logger -st ${0##*/} "/tmp/unattended.sh script launched in the background with PID \$!"
-	fi
-
-	logger -st ${0##*/} "Done !!"
-	EOF
-
-chmod +x /tmp/.trash/post-cleanup
-exec /tmp/.trash/post-cleanup
-

overlay/etc/modprobe.d/g_ether.conf

@@ -1,6 +0,0 @@
-# Copyright 2022 - 2023, macmpi
-# SPDX-License-Identifier: MIT
-
-# added to support USB-Ethernet gadget mode at boot for Pi devices
-
-options g_ether dev_addr=ea:64:2f:e8:19:94 host_addr=f6:67:ce:b3:c0:ea

overlay/etc/modprobe.d/headless_gadget.conf

@@ -0,0 +1,6 @@
+# SPDX-FileCopyrightText: Copyright 2022-2023, macmpi
+# SPDX-License-Identifier: MIT
+
+# support g_cdc USB-Ethernet gadget mode at boot for Pi devices
+
+options g_cdc dev_addr=ea:64:2f:e8:19:94 host_addr=f6:67:ce:b3:c0:ea

overlay/etc/modules-load.d/g_ether.conf

@@ -1,9 +0,0 @@
-# Copyright 2022 - 2023, macmpi
-# SPDX-License-Identifier: MIT
-
-# added to support USB-Ethernet gadget mode at boot for Pi devices
-# also requires dtoverlay=dwc2 is added to usercfg.txt or config.txt
-
-dwc2
-g_ether
-

overlay/etc/runlevels/default/headless_bootstrap

@@ -0,0 +1 @@
+../../init.d/headless_bootstrap

overlay/etc/runlevels/default/local

@@ -1 +0,0 @@
-/etc/init.d/local

overlay/usr/local/bin/headless_bootstrap

@@ -0,0 +1,306 @@
+#!/bin/sh
+
+# SPDX-FileCopyrightText: Copyright 2022-2023, macmpi
+# SPDX-License-Identifier: MIT
+
+HDLSBSTRP_VERSION="1.0"
+
+_apk() {
+	local cmd="$1"
+	local pkg="$2"
+
+	case $cmd in
+		add) # install only if not already present
+			if ! apk info | grep -wq "${pkg}"; then
+				apk add "$pkg" && printf '%s ' "${pkg}" >> /tmp/.trash/installed
+			fi
+		;;
+		del) # delete only if previously installed
+			if grep -wq "$pkg" /tmp/.trash/installed > /dev/null 2>&1; then
+				apk del "$pkg" && sed -i 's/\b'"${pkg}"'\b//' /tmp/.trash/installed
+			fi
+		;;
+		*)
+			echo "only add/del: wrong usage"; exit
+		;;
+	esac
+}
+
+_preserve() {
+# create a back-up of element (file, folder, symlink)
+	[ -z "${1}" ] && return 1
+	[ -e "$1" ] && cp -a "$1" "${1}.orig"
+}
+
+_restore() {
+# remove element (file, folder, symlink) and replace by
+# previous back-up if available
+	[ -z "${1}" ] && return 1
+	rm -rf "${1}"
+	[ -e "${1}.orig" ] && mv -f "${1}.orig" "${1}"
+}
+
+# shellcheck disable=SC2142  # known special case
+alias _logger='logger -st "${0##*/}"'
+
+##### End of part to be duplicated into headless_cleanup (do not alter!)
+
+_prep_cleanup() {
+## Prep for final headless_cleanup
+# clears any installed packages and settings
+# copy begininng of this file to keep functions
+sed -n '/^#* End .*alter!)$/q;p' /usr/local/bin/headless_bootstrap > /tmp/.trash/headless_cleanup
+cat <<-EOF >> /tmp/.trash/headless_cleanup
+	# Redirect stdout and errors to console as service won't show messages
+	exec 1>/dev/console 2>&1
+
+	_logger "Cleaning-up..."
+	_restore "/etc/ssh/sshd_config"
+	_restore "/etc/conf.d/sshd"
+	_apk del openssh-server
+	_restore "/etc/wpa_supplicant/wpa_supplicant.conf"
+	_apk del wpa_supplicant
+	_restore "/etc/network/interfaces"
+	_restore "/etc/hostname"
+	rm -f /etc/modprobe.d/headless_gadget.conf
+
+	# remove from boot service to avoid spurious openrc recalls from unattended script
+	rm -f /etc/runlevels/default/headless_bootstrap
+	rm -f /usr/local/bin/headless_bootstrap
+
+	# Run unattended script if available
+	install -m755 "${ovlpath}/unattended.sh" /tmp/headless_unattended > /dev/null 2>&1 && \
+		_logger "Starting headless_unattended service" && \
+		rc-service headless_unattended start
+
+	rm -f /etc/init.d/headless_*
+	_logger "Clean-up done, enjoy !"
+	cat /tmp/.trash/banner > /dev/console
+	if [ -c /dev/ttyGS0 ]; then
+		# Enabling terminal login into ttyGS0 serial for 60 sec
+		# no choice than making permanent change to pre 3.19 versions of /etc/securetty
+		grep -q "ttyGS0" /etc/securetty || echo "ttyGS0" >> /etc/securetty
+		/sbin/getty -L 115200 ttyGS0 vt100 &
+	fi
+	EOF
+chmod +x /tmp/.trash/headless_cleanup
+}
+
+_setup_sshd() {
+## Setup temporary SSH server (root login, no password)
+# We use some bundled (or optionaly provided) keys to avoid generation at startup and save time
+_apk add openssh-server
+_preserve "/etc/ssh/sshd_config"
+_preserve "/etc/conf.d/sshd"
+
+cat <<-EOF > /etc/ssh/sshd_config
+	PermitRootLogin yes
+	Banner /tmp/.trash/banner
+	EOF
+
+# Client authorized_keys or no authentication
+if install -m600 "${ovlpath}/authorized_keys" /tmp/.trash/authorized_keys > /dev/null 2>&1; then
+	_logger "Enabling public key SSH authentication..."
+	cat <<-EOF >> /etc/ssh/sshd_config
+		AuthenticationMethods publickey
+		AuthorizedKeysFile /tmp/.trash/authorized_keys
+		# relax strict mode as authorized_keys are inside /tmp
+		StrictModes no
+		EOF
+else
+	_logger "No SSH authentication."
+	cat <<-EOF >> /etc/ssh/sshd_config
+		AuthenticationMethods none
+		PermitEmptyPasswords yes
+		EOF
+fi
+
+# Server keys: inject optional custom keys, or generate new (might be stored),
+# or use bundeled ones (not stored)
+local keygen_stance="sshd_disable_keygen=yes"
+if install -m600 "${ovlpath}"/ssh_host_*_key* /etc/ssh/ > /dev/null 2>&1; then
+	# check for empty key within injected ones: if found, generate new keys
+	if find /etc/ssh/ -maxdepth 1 -type f -name 'ssh_host_*_key*' -empty | grep -q .; then
+		rm /etc/ssh/ssh_host_*_key*
+		keygen_stance=""
+		_logger "Will generate new SSH keys..."
+	else
+		chmod 644 /etc/ssh/ssh_host_*_key.pub
+		_logger "Using injected SSH keys..."
+	fi
+else
+	_logger "Using bundled ssh keys from RAM..."
+	cat <<-EOF >> /etc/ssh/sshd_config
+		HostKey /tmp/.trash/ssh_host_ed25519_key
+		HostKey /tmp/.trash/ssh_host_rsa_key
+		EOF
+fi
+
+echo "$keygen_stance" >> /etc/conf.d/sshd
+rc-service sshd restart
+}
+
+_tst_version() {
+# Tested URL redirects to github project page: is.gd shortener provides basic analytics.
+# Analytics are public and can be checked at https://is.gd/stats.php?url=apkovl_run
+# Privacy policy: https://is.gd/privacy.php
+local new_vers=""
+local status="failed"
+local ref="/macmpi/alpine-linux-headless-bootstrap/releases/tag/v"
+if wget -q -O /tmp/homepg -T 10 https://is.gd/apkovl_run > /dev/null 2>&1; then
+	status="success"
+	ver="$( grep -o "$ref.*\"" /tmp/homepg | grep -Eo '[0-9]+[\.[0-9]+]*' )"
+	rm -f /tmp/homepg
+	[ -n "$ver" ] && ! [ "$ver" = "$HDLSBSTRP_VERSION" ] && \
+		new_vers="!! Version $ver is available on Github project page !!" && \
+		_logger "$new_vers" && \
+		printf '%s\n\n' "$new_vers" >> /tmp/.trash/banner
+fi
+_logger "Internet access: $status"
+}
+
+_setup_networking() {
+## Setup Network interfaces
+if [ -d "/sys/class/net/wlan0" ] && [ -f "${ovlpath}/wpa_supplicant.conf" ]; then
+	_logger "Configuring wifi..."
+	_apk add wpa_supplicant
+	_preserve "/etc/wpa_supplicant/wpa_supplicant.conf"
+	install -m600 "${ovlpath}/wpa_supplicant.conf" /etc/wpa_supplicant/wpa_supplicant.conf
+else
+	_logger "No wifi interface or setup file supplied"
+fi
+
+_preserve "/etc/network/interfaces"
+if ! install -m644 "${ovlpath}/interfaces" /etc/network/interfaces > /dev/null 2>&1; then
+	# set default interfaces if not specified by interface file on boot storage
+	_logger "No interfaces file supplied, building defaults..."
+	for dev in /sys/class/net/*; do
+		dev="$(basename "$dev")"
+		case ${dev%%[0-9]*} in
+			lo)
+					cat <<-EOF >> /etc/network/interfaces
+					auto $dev
+					iface $dev inet loopback
+
+					EOF
+					;;
+			eth)
+					cat <<-EOF >> /etc/network/interfaces
+					auto $dev
+					iface $dev inet dhcp
+
+					EOF
+					;;
+			wlan)
+					[ -f /etc/wpa_supplicant/wpa_supplicant.conf ] && cat <<-EOF >> /etc/network/interfaces
+					auto $dev
+					iface $dev inet dhcp
+
+					EOF
+					;;
+			usb)
+					cat <<-EOF >> /etc/network/interfaces
+					auto $dev
+					iface $dev inet static
+					    address 10.42.0.2/24
+					    gateway 10.42.0.1
+
+					EOF
+
+					cat <<-EOF > /etc/resolv.conf
+					nameserver 208.67.222.222
+					nameserver 208.67.220.220
+
+					EOF
+					;;
+		esac
+	done
+fi
+
+echo "###################################"
+echo "Using following network interfaces:"
+cat /etc/network/interfaces
+echo "###################################"
+
+_preserve "/etc/hostname"
+echo "alpine-headless" > /etc/hostname
+hostname -F /etc/hostname
+
+grep -q "wlan" /etc/network/interfaces && \
+	[ -f /etc/wpa_supplicant/wpa_supplicant.conf ] && \
+		rc-service wpa_supplicant restart
+rc-service networking restart
+}
+
+_setup_gadget() {
+# load composite USB Serial/USB Ethernel driver & setup terminal
+_logger "Enabling USB-gadget Serial and Ethernet ports"
+lsmod | grep -q "dwc2" || modprobe -qs dwc2
+modprobe -qs g_cdc
+# default config: xon/xoff flow control
+stty -g -F /dev/ttyGS0 >/dev/null 2>&1 && setconsole /dev/ttyGS0
+# notes to users willing to connect from Linux Ubuntu-based host terminal:
+# - user on host needs to be part of dialout group (reboot required), and
+# - disable spurious AT commands from ModemManager on host-side Gadget serial port
+# you may create a /etc/udev/rules.d/99-ttyacms-gadget.rules as per:
+# https://linux-tips.com/t/prevent-modem-manager-to-capture-usb-serial-devices/284/2
+# ATTRS{idVendor}=="0525" ATTRS{idProduct}=="a4aa", ENV{ID_MM_DEVICE_IGNORE}="1"
+}
+
+
+#############################################################################
+## Main
+
+# Redirect stdout and errors to console as service won't show messages
+exec 1>/dev/console 2>&1
+_logger "Alpine Linux headless bootstrap v$HDLSBSTRP_VERSION by macmpi"
+
+# help randomness for wpa_supplicant and sshd (urandom until 3.16)
+rc-service seedrng restart || rc-service urandom restart
+
+# setup USB gadget mode if device has compatible device-tree
+find /proc/device-tree/soc/usb* -name "dr_mode" -print0 | \
+	xargs -0 grep -q "peripheral" && _setup_gadget
+
+# Determine ovl file location
+# 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}/${ovl}"
+fi
+
+# Create banner file
+warn=""
+grep -q "${ovlpath}.*[[:space:]]ro[[:space:],]" /proc/mounts; RO=$?
+[ "$RO" -eq "0" ] && warn="(remount partition rw!)"
+cat <<-EOF > /tmp/.trash/banner
+
+	Alpine Linux headless bootstrap v$HDLSBSTRP_VERSION by macmpi
+	
+	You may want to delete/rename .apkovl file before reboot ${warn}:
+	${ovl}
+	(can be done automatically with unattended script - see sample snippet)
+
+
+	EOF
+
+_setup_networking
+
+# Test latest available version online
+# Can be skipped by creating a 'opt-out'-named dummy file aside apkovl file
+[ -f "${ovlpath}/opt-out" ] || _tst_version &
+
+# setup sshd unless unattended.sh script prevents it
+grep -q "^#NO_SSH$" "${ovlpath}/unattended.sh" > /dev/null 2>&1 \
+	|| _setup_sshd
+
+_prep_cleanup
+_logger "Initial setup done, handing-over to clean-up"
+rc-service headless_cleanup start
+exit 0
+

sample_interfaces

@@ -1,4 +1,4 @@
-# Copyright 2022 - 2023, macmpi
+# SPDX-FileCopyrightText: Copyright 2022-2023, macmpi
 # SPDX-License-Identifier: MIT
 
 # Sample network interfaces file
@@ -8,15 +8,12 @@ iface lo inet loopback
 
 auto eth0
 iface eth0 inet dhcp
-	hostname localhost
 
 auto wlan0
 iface wlan0 inet dhcp
-	hostname localhost
 
 auto usb0
 iface usb0 inet static
-    address 10.42.0.2/24
+	address 10.42.0.2/24
 	gateway 10.42.0.1
-	hostname localhost
 

sample_unattended.sh

@@ -1,29 +1,45 @@
-#/bin/sh
+#!/bin/sh
 
-# Copyright 2022 - 2023, macmpi
+# 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
 
-## Obvious one; reminder: is run in the background
+# To prevent headless bootstrap script from starting sshd
-echo hello world !!
+# only keep a single starting # on the line below
+##NO_SSH
+
+# Uncomment to enable stdout and errors redirection to console (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 $5}' | sed 's/:.*$//' )"
-ovl="$( basename "${ovl}" )"
+if [ -f "${ovl}" ]; then
-# search path again as mountpoint may have been changed later in the boot process...
+	ovlpath="$( dirname "$ovl" )"
-ovlpath=$( find /media -maxdepth 2 -type d -path '*/.*' -prune -o -type f -name "${ovl}" -exec dirname {} \; | head -1 )
+else
+	# search path again as mountpoint have been changed later in the boot process...
+	ovl="$( 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 "${ovlpath}/${ovl}"
+rm -f "${ovl}"
 [ "$RO" -eq "0" ] && mount -o remount,ro "${ovlpath}"
 
 ########################################################
@@ -33,7 +49,7 @@ rm -f "${ovlpath}/${ovl}"
 # 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 -st ${0##*/} "Setting-up minimal environment"
+_logger "Setting-up minimal environment"
 
 cat <<-EOF > /tmp/ANSWERFILE
 	# base answer file for setup-alpine script
@@ -88,5 +104,5 @@ lbu commit -d
 ########################################################
 
 
-logger -st ${0##*/} "Finished unattended script"
+_logger "Finished unattended script"
 

sample_wpa_supplicant.conf

@@ -1,4 +1,4 @@
-# Copyright 2022 - 2023, macmpi
+# SPDX-FileCopyrightText: Copyright 2022-2023, macmpi
 # SPDX-License-Identifier: MIT
 
 # Sample wpa_supplicant.conf