mooooore stuffs

home/home.nix

@@ -26,6 +26,25 @@
     netcat
     neovim
     firefox
-  ];
+  ]
+      ++ (
+      with lib; let
+        # this function extracts the base file name from a path.
+        basename = path: lib.lists.last (lib.strings.splitString "/" (toString path));
+
+        files = lib.filesystem.listFilesRecursive ./scripts;
+      in
+        # for each script found, create a derivation installed in $PATH
+        lib.lists.forEach files (
+          file: let
+            scriptName = strings.removeSuffix ".sh" (basename file);
+          in
+            pkgs.writeScriptBin
+            # (basename file) # the new package's name
+            scriptName
+            (builtins.readFile file)
+        )
+    );
+
 
 }

home/scripts/lxc/lab-create.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+USER="$1"
+KEYFILE="$2"
+CONTAINER="lxc-${USER}"
+
+echo "Creating LXC container ${CONTAINER}..."
+lxc-create -n "$CONTAINER" -t download -- -d ubuntu -r noble -a amd64
+
+# start it
+lxc-start -n "$CONTAINER"
+
+# wait for networking
+sleep 5
+
+# set root password, install SSH, inject key
+lxc-attach -n "$CONTAINER" -- bash -c "
+  apt-get update && apt-get install -y openssh-server
+  mkdir -p /root/.ssh
+  chmod 700 /root/.ssh
+  sed -i 's/#PermitRootLogin.*/PermitRootLogin prohibit-password/' /etc/ssh/sshd_config
+  systemctl enable ssh
+  systemctl restart ssh
+"
+
+# push the key in
+cat "$KEYFILE" | lxc-attach -n "$CONTAINER" -- tee /root/.ssh/authorized_keys > /dev/null
+lxc-attach -n "$CONTAINER" -- chmod 600 /root/.ssh/authorized_keys
+
+# auto-start on boot
+echo "lxc.start.auto = 1" >> "/var/lib/lxc/${CONTAINER}/config"
+
+# get container IP
+CONTAINER_IP=$(lxc-info -n "$CONTAINER" -iH | head -1)
+
+# create host user that maps to this container
+useradd -m -s /bin/bash -G labmates "$USER" 2>/dev/null || true
+mkdir -p "/home/${USER}/.ssh"
+cp "$KEYFILE" "/home/${USER}/.ssh/authorized_keys"
+chown -R "${USER}:${USER}" "/home/${USER}/.ssh"
+chmod 700 "/home/${USER}/.ssh"
+
+# store mapping
+echo "$CONTAINER" > "/home/${USER}/.lxc-container"
+
+echo "Done. ${USER} SSH -> root@${CONTAINER} (${CONTAINER_IP})"

home/scripts/lxc/lab-delete.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -euo pipefail
+USER="$1"
+CONTAINER=$(cat "/home/${USER}/.lxc-container" 2>/dev/null)
+# [[ -n "$CONTAINER" ]] && lxc-stop -n "$CONTAINER" 2>/dev/null; lxc-destroy -n "$CONTAINER"
+if [[ -n "$CONTAINER" ]]; then
+  lxc-stop -n "$CONTAINER" 2>/dev/null
+  lxc-destroy -n "$CONTAINER"
+fi
+userdel -r "$USER" 2>/dev/null || true
+echo "Removed ${USER} and ${CONTAINER}"

home/scripts/lxc/lab-list.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+printf "%-15s %-20s %-16s %s\n" "USER" "CONTAINER" "IP" "STATE"
+for f in /home/*/.lxc-container; do
+  [[ -f "$f" ]] || continue
+  U=$(basename "$(dirname "$f")")
+  C=$(cat "$f")
+  IP=$(lxc-info -n "$C" -iH 2>/dev/null | head -1)
+  STATE=$(lxc-info -n "$C" -sH 2>/dev/null)
+  printf "%-15s %-20s %-16s %s\n" "$U" "$C" "${IP:-n/a}" "${STATE:-n/a}"
+done

home/scripts/lxc/lxc-login.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+# CONTAINER=$(cat "/home/${USER}/.lxc-container" 2>/dev/null)
+CONTAINER=$(cat "/home/$(whoami)/.lxc-container" 2>/dev/null)
+
+if [[ -z "$CONTAINER" ]]; then
+  echo "No container assigned. Contact admin."
+  exit 1
+fi
+
+# ensure running
+lxc-start -n "$CONTAINER" 2>/dev/null || true
+
+if [[ -n "$SSH_ORIGINAL_COMMAND" ]]; then
+  exec lxc-attach -n "$CONTAINER" -- bash -c "$SSH_ORIGINAL_COMMAND"
+else
+  exec lxc-attach -n "$CONTAINER" -- login -f root
+fi

hosts/s1901/hardware-configuration.nix

@@ -13,10 +13,10 @@
   boot.kernelModules = [ "kvm-intel" ];
   boot.extraModulePackages = [ ];
 
-  # fileSystems."/" =
+  fileSystems."/" =
-    # { device = "/dev/disk/by-uuid/05ca9d56-3506-43c5-b9ec-be928b782996";
+    { device = "/dev/disk/by-uuid/05ca9d56-3506-43c5-b9ec-be928b782996";
-      # fsType = "ext4";
+      fsType = "ext4";
-    # };
+    };
 
   # fileSystems."/home/synchronous/.agenix/agenix.d" =
     # { device = "none";

system/lxc-default.conf

@@ -0,0 +1,5 @@
+lxc.net.0.type = veth
+lxc.net.0.link = br0
+lxc.net.0.flags = up
+lxc.net.0.hwaddr = 00:16:3e:xx:xx:xx
+lxc.apparmor.profile = unconfined

system/lxc.nix

@@ -0,0 +1,68 @@
+# system/lxc.nix
+{ config, pkgs, ... }: {
+  virtualisation.lxc = {
+    enable = true;
+    lxcfs.enable = true;
+  };
+
+  networking.bridges.br0.interfaces = [];
+  networking.interfaces.br0.ipv4.addresses = [{
+    address = "10.100.0.1";
+    prefixLength = 24;
+  }];
+
+  # wildcard masquerade — no need to specify external interface per host
+  networking.nat.enable = false;
+  networking.nftables.enable = true;
+  networking.nftables.tables.lab-nat = {
+    family = "ip";
+    content = ''
+      chain postrouting {
+        type nat hook postrouting priority 100;
+        ip saddr 10.100.0.0/24 oifname != "br0" masquerade
+      }
+    '';
+  };
+
+  # IP forwarding
+  boot.kernel.sysctl."net.ipv4.ip_forward" = 1;
+
+  # DHCP for containers on the bridge
+  services.dnsmasq = {
+    enable = true;
+    settings = {
+      interface = "br0";
+      bind-interfaces = true;
+      dhcp-range = "10.100.0.10,10.100.0.200,24h";
+      dhcp-option = [ "3,10.100.0.1" "6,8.8.8.8,1.1.1.1" ];
+    };
+  };
+
+  # labmates get dropped into their container
+  services.openssh.extraConfig = ''
+    Match Group labmates
+      ForceCommand /usr/local/bin/lxc-login
+      AllowTcpForwarding no
+      X11Forwarding no
+  '';
+
+  users.groups.labmates = {};
+
+  environment.systemPackages = with pkgs; [
+    lxc
+    lxc-templates
+    debootstrap
+    bridge-utils
+  ];
+
+  environment.etc."lxc/default.conf".text = ''
+    lxc.net.0.type = veth
+    lxc.net.0.link = br0
+    lxc.net.0.flags = up
+    lxc.net.0.hwaddr = 00:16:3e:xx:xx:xx
+    lxc.apparmor.profile = unconfined
+  '';
+
+  environment.etc."local/bin/lxc-login".source = ../home/scripts/lxc/lxc-login.sh;
+  environment.etc."local/bin/lxc-login".mode = "0755";
+}

system/system.nix

@@ -5,7 +5,8 @@
 }: {
   imports = [
     ./ssh.nix
-    ./disko-config.nix
+    ./lxc.nix
+    # ./disko-config.nix
   ];
 
   # Set your time zone.