nixos-infra/nixos-infra/scripts/create-lxc-nixos.sh

#!/usr/bin/env bash
set -euo pipefail

# --- Dependencies ---
# Check if docopts is installed (for Bash)
if ! command -v docopts &> /dev/null; then
  echo "❌ Error: 'docopts' is required for Bash." >&2
  echo "See https://github.com/docopt/docopts to install it." >&2
  exit 1
fi

# --- Usage and Documentation ---
usage="Create and configure an LXC container on a remote Proxmox VE 9 server.

Usage:
  $0 <short_name> [options]

Options:
  -h, --help                Show this message.
  -t, --template TEMPLATE    LXC template (e.g. local:vztmpl/nixos-unstable).
  -r, --rootfs-size SIZE    Root filesystem size (e.g. 8G).
  -c, --cores CORES         Number of CPU cores.
  -m, --memory MEMORY       RAM in MiB.
  -s, --swap SWAP           Swap in MiB.
  -p, --password PASSWORD   Root password for the container.
  -b, --bridge BRIDGE       Network bridge (e.g. vmbr0).
  -v, --vlan VLAN           VLAN tag (e.g. tag=10).
  -d, --domain DOMAIN       DNS domain.
  -u, --unprivileged UNPRIV  Unprivileged container (0 or 1).
  -i, --ip IP               Static IP (e.g. 192.168.1.100/24).
  -C, --cmode CMODE         Console mode (console or tty). Default: console.
  -T, --tags TAGS           Tags for the container (optional).
  -k, --ssh-public-keys KEYS SSH public keys for the container.
  --pve-host HOST           Proxmox host (e.g. pve).
  --pve-user USER           Proxmox user (default: admin).
  --pve-port PORT           SSH port for Proxmox (default: 22).
  --pve-password PASSWORD  Password for SSH authentication on Proxmox.
  --pve-ssh-key KEY         SSH key file for authentication.
  --dry-run                 Simulate container creation without execution.
"

# --- Default Parameters (Environment Variables) ---
# Proxmox Server
PVE_HOST="${PVE_HOST:-}"
PVE_USER="${PVE_USER:-admin}"
PVE_PORT="${PVE_PORT:-22}"
PVE_PASSWORD="${PVE_PASSWORD:-}"
PVE_SSH_KEY="${PVE_SSH_KEY:-}"
DRY_RUN="${DRY_RUN:-false}"

# LXC Container
TEMPLATE="${TEMPLATE:-local:vztmpl/nixos-unstable-amd64-default_20260428}"
ROOTFS_SIZE="${ROOTFS_SIZE:-8G}"
CORES="${CORES:-2}"
MEMORY="${MEMORY:-2048}"
SWAP="${SWAP:-1024}"
PASSWORD="${PASSWORD:-changeme}"
BRIDGE="${BRIDGE:-vmbr0}"
VLAN="${VLAN:-}"
DOMAIN="${DOMAIN:-lagraula.fr}"
UNPRIVILEGED="${UNPRIVILEGED:-0}"
IP="${IP:-}"
CMODE="${CMODE:-console}"
TAGS="${TAGS:-}"
SSH_PUBLIC_KEYS="${SSH_PUBLIC_KEYS:-}"

# --- Parse Arguments with docopts (Lowest Priority) ---
args=$(docopts -h "$usage" : "$@")
eval "$args"

# Short name of the machine (mandatory parameter)
SHORT_NAME="${argv[0]:-}"
if [ -z "$SHORT_NAME" ]; then
  echo "❌ Error: The short name of the machine is required." >&2
  echo "$usage" >&2
  exit 1
fi

# --- Override with /etc/nixos-infra/hosts/<short_name> (Medium Priority)
if [ -f "/etc/nixos-infra/hosts/$SHORT_NAME" ]; then
  echo "📄 Applying parameters from /etc/nixos-infra/hosts/$SHORT_NAME..."
  set -a
  source "/etc/nixos-infra/hosts/$SHORT_NAME"
  set +a
fi

# --- Override with ./<short_name> (Medium Priority) ---
if [ -f "./$SHORT_NAME" ]; then
  echo "📄 Applying parameters from ./$SHORT_NAME..."
  set -a
  source "./$SHORT_NAME"
  set +a
fi

# --- Apply Command-Line Arguments (Highest Priority) ---
eval "$args"

# --- SSH Key Default Logic ---
if [ "$PVE_SSH_KEY" = "default" ]; then
  PVE_SSH_KEY="${HOME}/.ssh/id_${PVE_USER}"
elif [ -z "$PVE_SSH_KEY" ] && [ -z "$PVE_PASSWORD" ]; then
  PVE_SSH_KEY="${HOME}/.ssh/id_${PVE_USER}"
fi

# --- Critical Parameters Validation ---
if [ -z "$TEMPLATE" ] || [ -z "$ROOTFS_SIZE" ] || [ -z "$CORES" ] || \
   [ -z "$MEMORY" ] || [ -z "$SWAP" ] || [ -z "$PASSWORD" ] || \
   [ -z "$BRIDGE" ] || [ -z "$DOMAIN" ] || [ -z "$UNPRIVILEGED" ] || \
   [ -z "$CMODE" ] || [ -z "$SSH_PUBLIC_KEYS" ] || \
   [ -z "$PVE_HOST" ] || [ -z "$PVE_USER" ] || [ -z "$PVE_PORT" ]; then
  echo "❌ Error: One or more critical parameters are missing." >&2
  exit 1
fi

# Authentication Validation
if [ -z "$PVE_PASSWORD" ]; then
  if [ -z "$PVE_SSH_KEY" ]; then
    echo "❌ Error: No authentication parameter is defined." >&2
    exit 1
  elif [ ! -f "$PVE_SSH_KEY" ]; then
    echo "❌ Error: SSH key file '$PVE_SSH_KEY' does not exist." >&2
    exit 1
  fi
fi

# --- SSH Connection to Proxmox Server ---
run_proxmox() {
  local ssh_cmd="ssh -p $PVE_PORT"
  if [ -n "$PVE_SSH_KEY" ] && [ -f "$PVE_SSH_KEY" ]; then
    ssh_cmd="$ssh_cmd -i $PVE_SSH_KEY"
  else
    ssh_cmd="$ssh_cmd -o PreferredAuthentications=password \
             -o StrictHostKeyChecking=no"
  fi
  $ssh_cmd "$PVE_USER@$PVE_HOST" "$1"
}

# --- Network Options Construction ---
NET_OPTS="name=eth0,bridge=$BRIDGE"
if [ -n "$VLAN" ]; then
  NET_OPTS="$NET_OPTS,$VLAN"
fi
if [ -n "$IP" ]; then
  NET_OPTS="$NET_OPTS,ip=$IP"
fi

# --- Container Creation ---
echo "🚀 Creating LXC container $SHORT_NAME on $PVE_HOST..."
CREATE_CMD="pct create $ROOTFS_SIZE $TEMPLATE --cores $CORES \
--memory $MEMORY --swap $SWAP --hostname $SHORT_NAME.$DOMAIN \
--password $PASSWORD --unprivileged $UNPRIVILEGED --net0 $NET_OPTS \
--onboot 1 --cmode $CMODE --ssh-public-keys $SSH_PUBLIC_KEYS"
if [ -n "$TAGS" ]; then
  CREATE_CMD="$CREATE_CMD --tags $TAGS"
fi

# Display the command (with password masked)
DISPLAY_CMD=$(echo "$CREATE_CMD" |
  sed "s/--password [^ ]*/--password \*\*\*\*\*/g")
echo "🔧 Command to execute on $PVE_HOST: $DISPLAY_CMD"

# Execute or simulate
if [ "$DRY_RUN" = "true" ]; then
  echo "🧪 Dry run: Skipping actual execution."
else
  LXC_ID=$(run_proxmox "$CREATE_CMD" | grep -oP '\d+')
  if [ -z "$LXC_ID" ]; then
    echo "❌ Error: Failed to create the container." >&2
    exit 1
  fi
  echo "✅ LXC container $SHORT_NAME created successfully (ID: $LXC_ID)."
fi