#!/bin/sh
# LXC Container Setup - developed by acidvegas (https://git.acid.vegas/supertools)

# Configuration
SSH_PORT=1337
USER_NAME="supernets"
CONTAINER_NAME="ircd"

setup_root() {
	# Secure DNS (TEMP)
	printf "nameserver 208.67.222.222\nnameserver 208.67.220.220\nnameserver 2620:119:35::35\nnameserver 2620:119:53::53\n" > /etc/resolv.conf
	chattr +i /etc/resolv.conf

	# Update & Install Packages
	apt-get update && apt-get upgrade
	apt-get install bridge-utils dirmngr htop gpg lxc man net-tools uidmap screen unattended-upgrades

	# Wipe the journal and only use RAM storage
	journalctl --vacuum-time=1d
	printf "[Journal]\nStorage=volatile\nSplitMode=none\nRuntimeMaxUse=500K\n" > /etc/systemd/journald.conf
	systemctl restart systemd-journald

	# Install & setup dropbear
	apt-get install -y dropbear
	{
		echo "NO_START=0"
		echo "DROPBEAR_PORT=$SSH_PORT"
		echo "DROPBEAR_EXTRA_ARGS=\"-K 0\""
		echo "DROPBEAR_BANNER=\"\""
		echo "DROPBEAR_ED25519KEY=\"/etc/dropbear/dropbear_ed25519_host_key\""
		echo "DROPBEAR_RECEIVE_WINDOW=65536"
	} > /etc/default/dropbear
	systemctl restart dropbear && systemctl enable dropbear

	# Remove OpenSSH
	apt remove openssh-server && apt remove openssh-client
	apt purge openssh-server && apt purge openssh-client
	apt autoremove && apt autoclean
	systemctl stop ssh && systemctl disable ssh

	# Disable history, logs, & IPv6
	printf "\nHISTSIZE=0\nHISTFILESIZE=0\nunset HISTFILE\n" >> /etc/bash.bashrc
	>/var/log/lastlog && chattr +i /var/log/lastlog
	sed -i 's/GRUB_CMDLINE_LINUX=""/GRUB_CMDLINE_LINUX="ipv6.disable=1"/' /etc/default/grub && update-grub

	# Set locales
	echo "en_US.UTF-8 UTF-8" > /etc/locale.gen && locale-gen

	# Add a new user
	useradd -m -s /bin/bash $USER_NAME && passwd $USER_NAME

	# Change hostname
	nano /etc/hostname

	# Enable user-level services
	loginctl enable-linger $USER_NAME

	# Configure NAT
	iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
	echo "1" > /proc/sys/net/ipv4/ip_forward
	printf "\nnet.ipv4.ip_forward=1\n" > /etc/sysctl.conf

	# Create a runtime directory with the correct permissions
	mkdir -p /run/user/$(id -u $USER_NAME)
    chown $USER_NAME:$USER_NAME /run/user/$(id -u $USER_NAME)
    chmod 700 /run/user/$(id -u $USER_NAME)

	# Set the subordinate UID/GID
    echo "$USER_NAME:100000:65536" > /etc/subuid
    echo "$USER_NAME:100000:65536" > /etc/subgid

	# Create bridge (usually done automatically, see `ip addr` output for lxcbr0)
	#brctl addbr lxcbr0
	#ip addr add 192.168.1.10/24 dev lxcbr0
	#ip link set dev lxcbr0 up

	# Restart the LXC service
	systemctl restart lxc
}

setup_user() {
	# Add dropbear public key
	mkdir -p $HOME/.ssh
	printf "ssh-ed25519 loldongs acidvegas@blackhole" > $HOME/.ssh/authorized_keys
	chmod 700 $HOME/.ssh
	chown -R $USER $HOME/.ssh
	chmod 400 $HOME/.ssh/authorized_keys
	chattr +i $HOME/.ssh
	chattr +i $HOME/.ssh/authorized_keys

	# Setup LXC configuration
	mkdir -p ~/.config/lxc
	{
		echo "lxc.idmap = u 0 100000 65536"
		echo "lxc.idmap = g 0 100000 65536"
		echo "lxc.net.0.type = veth"
		echo "lxc.net.0.link = lxcbr0"
		echo "lxc.net.0.flags = up"
		echo "lxc.start.auto = 1"
		echo "lxc.start.delay = 5"
	} > $HOME/.config/lxc/default.conf

	# Setup runtime directory
	echo 'export XDG_RUNTIME_DIR=/run/user/$(id -u $USER)' >> ~/.bashrc
	export XDG_RUNTIME_DIR=/run/user/$(id -u $USER)

	# Create a systemd user service
	mkdir -p $HOME/.config/systemd/user
	{
		echo "[Unit]"
		echo "Description=LXC Container %I"
		echo "After=network.target"
		echo ""
		echo "[Service]"
		echo "Type=forking"
		echo "ExecStart=/usr/bin/lxc-start -n %i"
		echo "ExecStop=/usr/bin/lxc-stop -n %i"
		echo "Restart=on-failure"
		echo ""
		echo "[Install]"
		echo "WantedBy=default.target"
	} > $HOME/.config/systemd/user/lxc-container@.service

	# Create a container
	lxc-create -n $container -t download -- --dist debian --release bullseye --arch amd64

	# Start & enable the service
	systemctl --user enable lxc-container@${container}.service
	systemctl --user start  lxc-container@${container}.service
}

setup_container() {
	# TODO: Provision container for services
	return
}

#setup_root
#setup_user