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Author SHA1 Message Date
macmpi 6718b1c311 bump version to 0.7 2023-05-13 09:03:08 +02:00
macmpi 7e91859180 trigger new keys generation if supplied key file is empty 2023-05-13 08:30:47 +02:00
3 changed files with 21 additions and 21 deletions

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@ -1,7 +1,7 @@
# Deploy Alpine Linux on a headless system # Deploy Alpine Linux on a headless system
[Alpine Linux documentation](https://docs.alpinelinux.org/user-handbook/0.1a/Installing/setup_alpine.html) assumes **initial setup** is carried-out on a system with a keyboard & display to interract with.\ [Alpine Linux documentation](https://docs.alpinelinux.org/user-handbook/0.1a/Installing/setup_alpine.html) assumes **initial setup** is carried-out on a system with a keyboard & display to interract with.\
However, there are many cases where one might want to deploy a headless system, only available through a network connection (ethernet, wifi or as USB ethernet gadget). 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 boot such headless system (leveraging Alpine distro's `initramfs` feature): it starts a basic ssh server to log-into from another Computer, in order to then perform actual system setup. This repo provides an **overlay file** to initially boot such headless system (leveraging Alpine distro's `initramfs` feature): it starts a basic ssh server to log-into from another Computer, in order to then perform actual system setup.
@ -11,15 +11,14 @@ Please follow [Alpine Linux Wiki](https://wiki.alpinelinux.org/wiki/Installation
Tools provided here can be used on any plaform for any install modes (diskless, data disk, system disk). 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://github.com/macmpi/alpine-linux-headless-bootstrap/raw/main/headless.apkovl.tar.gz)[^1] 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://github.com/macmpi/alpine-linux-headless-bootstrap/raw/main/headless.apkovl.tar.gz)[^1] overlay file 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 if using wifi), system can then be accessed under `ssh` with: \ With default network interface definitions (and SSID/pass file if using wifi), system can then be remotely accessed with: `ssh root@<IP>`\
`ssh root@<IP>`\
(system IP address may be determined with any IP scanning tools such as `nmap`). (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 setup!).\
From there, 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). 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).
Add-on files may be added next to `headless.apkovl.tar.gz` to customise boostrapping configuration (sample files are provided): Extra files may be added next to `headless.apkovl.tar.gz` to customise boostrapping configuration (check sample files):
- `wpa_supplicant.conf`[^2] (*mandatory for wifi usecase*): define wifi SSID & password. - `wpa_supplicant.conf`[^2] (*mandatory for wifi usecase*): define wifi SSID & password.
- `interfaces`[^2] (*optional*): define network interfaces at will, if defaults DCHP-based are not suitable. - `interfaces`[^2] (*optional*): define network interfaces at will, if defaults DCHP-based are not suitable.
- `ssh_host_*_key*` (*optional*): provide custom ssh keys to be injected (may be stored), instead of using bundled ones[^1] (not stored). Providing an empty key file will trigger new keys generation (ssh server may take longer to start). - `ssh_host_*_key*` (*optional*): provide custom ssh keys to be injected (may be stored), instead of using bundled ones[^1] (not stored). Providing an empty key file will trigger new keys generation (ssh server may take longer to start).
@ -27,9 +26,8 @@ Add-on files may be added next to `headless.apkovl.tar.gz` to customise boostrap
**Goody:** seamless USB bootstrapping for PiZero devices (or similar supporting USB ethernet gadget networking):\ **Goody:** seamless USB bootstrapping for PiZero devices (or similar supporting USB ethernet gadget networking):\
Just add `dtoverlay=dwc2` in `usercfg.txt` (or `config.txt`), and plug-in USB cable to Computer port.\ Just add `dtoverlay=dwc2` in `usercfg.txt` (or `config.txt`), and plug USB cable into 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:\ 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`
`ssh root@10.42.0.2`
Main execution steps are logged in `/var/log/messages`. Main execution steps are logged in `/var/log/messages`.

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@ -3,7 +3,7 @@
# Copyright 2022 - 2023, macmpi # Copyright 2022 - 2023, macmpi
# SPDX-License-Identifier: MIT # SPDX-License-Identifier: MIT
VERSION="0.6" VERSION="0.7"
# Redirect stdout and errors to console as rc.local does not log anything # Redirect stdout and errors to console as rc.local does not log anything
exec 1>/dev/console 2>&1 exec 1>/dev/console 2>&1
@ -82,7 +82,7 @@ rc-service networking start
## Setup temporary SSH server (root login, no password) ## Setup temporary SSH server (root login, no password)
## we use some bundled or optionaly provided keys to avoid generation at boot and save time ## we use some bundled or optionaly provided keys to avoid generation at startup and save time
apk add openssh apk add openssh
cp /etc/ssh/sshd_config /etc/ssh/sshd_config.orig cp /etc/ssh/sshd_config /etc/ssh/sshd_config.orig
cp /etc/conf.d/sshd /etc/conf.d/sshd.orig cp /etc/conf.d/sshd /etc/conf.d/sshd.orig
@ -94,33 +94,35 @@ cat <<-EOF >> /etc/ssh/sshd_config
Banner /tmp/.trash/banner Banner /tmp/.trash/banner
EOF EOF
# banner file # Banner file
cat <<-EOF > /tmp/.trash/banner cat <<-EOF > /tmp/.trash/banner
Alpine Linux headless bootstrap v$VERSION by macmpi Alpine Linux headless bootstrap v$VERSION by macmpi
EOF EOF
# bundled temporary keys are moved in RAM /tmp so they won't be stored # Bundled temporary keys are moved in RAM /tmp so they won't be stored
# within permanent config later (new ones will then be generated) # within permanent config later (new ones will then be generated)
KEYGEN_STANCE="sshd_disable_keygen=yes" KEYGEN_STANCE="sshd_disable_keygen=yes"
mv /etc/ssh/ssh_host_*_key* /tmp/.trash/. 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 # Inject optional custom keys (those might be stored)
logger -st ${0##*/} "Using bundled ssh keys from RAM..." if install -m600 "${ovlpath}"/ssh_host_*_key* /etc/ssh/; then
cat <<-EOF >> /etc/ssh/sshd_config # check for empty key within injected ones: generate new keys if found
HostKey /tmp/.trash/ssh_host_ed25519_key
HostKey /tmp/.trash/ssh_host_rsa_key
EOF
else
# look for empty key within injected ones: generate new keys if found
if find /etc/ssh/ -maxdepth 1 -type f -name 'ssh_host_*_key*' -empty | grep -q .; then if find /etc/ssh/ -maxdepth 1 -type f -name 'ssh_host_*_key*' -empty | grep -q .; then
rm /etc/ssh/ssh_host_*_key* rm /etc/ssh/ssh_host_*_key*
KEYGEN_STANCE="" KEYGEN_STANCE=""
logger -st ${0##*/} "Will generate new SSH keys..." logger -st ${0##*/} "Will generate new SSH keys..."
else else
chmod 644 /etc/ssh/ssh_host_*_key.pub
logger -st ${0##*/} "Using injected SSH keys..." logger -st ${0##*/} "Using injected SSH keys..."
fi fi
else
logger -st ${0##*/} "Using bundled ssh keys from RAM..."
cat <<-EOF >> /etc/ssh/sshd_config
HostKey /tmp/.trash/ssh_host_ed25519_key
HostKey /tmp/.trash/ssh_host_rsa_key
EOF
fi fi
echo "$KEYGEN_STANCE" >> /etc/conf.d/sshd echo "$KEYGEN_STANCE" >> /etc/conf.d/sshd