added installer

python/installer/__main__.py

@@ -0,0 +1,306 @@
+"""Install NixOS on a ZFS pool."""
+
+from __future__ import annotations
+
+import curses
+import logging
+import sys
+from os import getenv
+from pathlib import Path
+from random import getrandbits
+from subprocess import PIPE, Popen, run
+from time import sleep
+from typing import TYPE_CHECKING
+
+from python.common import configure_logger
+from python.installer.tui import draw_menu
+
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
+
+def bash_wrapper(command: str) -> str:
+    """Execute a bash command and capture the output.
+
+    Args:
+        command (str): The bash command to be executed.
+
+    Returns:
+        Tuple[str, int]: A tuple containing the output of the command (stdout) as a string,
+        the error output (stderr) as a string (optional), and the return code as an integer.
+    """
+    logging.debug(f"running {command=}")
+    # This is a acceptable risk
+    process = Popen(command.split(), stdout=PIPE, stderr=PIPE)
+    output, _ = process.communicate()
+    if process.returncode != 0:
+        error = f"Failed to run command {command=} return code {process.returncode=}"
+        raise RuntimeError(error)
+
+    return output.decode()
+
+
+def partition_disk(disk: str, swap_size: int, reserve: int = 0) -> None:
+    """Partition a disk.
+
+    Args:
+        disk (str): The disk to partition.
+        swap_size (int): The size of the swap partition in GB.
+            minimum value is 1.
+        reserve (int, optional): The size of the reserve partition in GB. Defaults to 0.
+            minimum value is 0.
+    """
+    logging.info(f"partitioning {disk=}")
+    swap_size = max(swap_size, 1)
+    reserve = max(reserve, 0)
+
+    bash_wrapper(f"blkdiscard -f {disk}")
+
+    if reserve > 0:
+        msg = f"Creating swap partition on {disk=} with size {swap_size=}GiB and reserve {reserve=}GiB"
+        logging.info(msg)
+
+        swap_start = swap_size + reserve
+        swap_partition = f"mkpart swap -{swap_start}GiB -{reserve}GiB "
+    else:
+        logging.info(f"Creating swap partition on {disk=} with size {swap_size=}GiB")
+        swap_start = swap_size
+        swap_partition = f"mkpart swap -{swap_start}GiB 100% "
+
+    logging.debug(f"{swap_partition=}")
+
+    create_partitions = (
+        f"parted --script --align=optimal {disk} -- "
+        "mklabel gpt "
+        "mkpart EFI 1MiB 4GiB "
+        f"mkpart root_pool 4GiB -{swap_start}GiB "
+        f"{swap_partition}"
+        "set 1 esp on"
+    )
+    bash_wrapper(create_partitions)
+
+    logging.info(f"{disk=} successfully partitioned")
+
+
+def create_zfs_pool(pool_disks: Sequence[str], mnt_dir: str) -> None:
+    """Create a ZFS pool.
+
+    Args:
+        pool_disks (Sequence[str]): A tuple of disks to use for the pool.
+        mnt_dir (str): The mount directory.
+    """
+    if len(pool_disks) <= 0:
+        error = "disks must be a tuple of at least length 1"
+        raise ValueError(error)
+
+    zpool_create = (
+        "zpool create "
+        "-o ashift=12 "
+        "-o autotrim=on "
+        f"-R {mnt_dir} "
+        "-O acltype=posixacl "
+        "-O canmount=off "
+        "-O dnodesize=auto "
+        "-O normalization=formD "
+        "-O relatime=on "
+        "-O xattr=sa "
+        "-O mountpoint=legacy "
+        "-O compression=zstd "
+        "-O atime=off "
+        "root_pool "
+    )
+    if len(pool_disks) == 1:
+        zpool_create += pool_disks[0]
+    else:
+        zpool_create += "mirror "
+        zpool_create += " ".join(pool_disks)
+
+    bash_wrapper(zpool_create)
+    zpools = bash_wrapper("zpool list -o name")
+    if "root_pool" not in zpools.splitlines():
+        logging.critical("Failed to create root_pool")
+        sys.exit(1)
+
+
+def create_zfs_datasets() -> None:
+    """Create ZFS datasets."""
+    bash_wrapper("zfs create -o canmount=noauto -o reservation=10G root_pool/root")
+    bash_wrapper("zfs create root_pool/home")
+    bash_wrapper("zfs create root_pool/var -o reservation=1G")
+    bash_wrapper("zfs create -o compression=zstd-9 -o reservation=10G root_pool/nix")
+    datasets = bash_wrapper("zfs list -o name")
+
+    expected_datasets = {
+        "root_pool/root",
+        "root_pool/home",
+        "root_pool/var",
+        "root_pool/nix",
+    }
+    missing_datasets = expected_datasets.difference(datasets.splitlines())
+    if missing_datasets:
+        logging.critical(f"Failed to create pools {missing_datasets}")
+        sys.exit(1)
+
+
+def get_cpu_manufacturer() -> str:
+    """Get the CPU manufacturer."""
+    output = bash_wrapper("cat /proc/cpuinfo")
+
+    id_vendor = {"AuthenticAMD": "amd", "GenuineIntel": "intel"}
+
+    for line in output.splitlines():
+        if "vendor_id" in line:
+            return id_vendor[line.split(": ")[1].strip()]
+
+    error = "Failed to get CPU manufacturer"
+    raise RuntimeError(error)
+
+
+def get_boot_drive_id(disk: str) -> str:
+    """Get the boot drive ID."""
+    output = bash_wrapper(f"lsblk -o UUID {disk}-part1")
+    return output.splitlines()[1]
+
+
+def create_nix_hardware_file(mnt_dir: str, disks: Sequence[str], encrypt: str | None) -> None:
+    """Create a NixOS hardware file."""
+    cpu_manufacturer = get_cpu_manufacturer()
+
+    devices = ""
+    if encrypt:
+        disk = disks[0]
+
+        devices = (
+            f'     luks.devices."luks-root-pool-{disk.split("/")[-1]}-part2"'
+            "= {\n"
+            f'        device = "{disk}-part2";\n'
+            "        bypassWorkqueues = true;\n"
+            "        allowDiscards = true;\n"
+            "      };\n"
+        )
+
+    host_id = format(getrandbits(32), "08x")
+
+    nix_hardware = (
+        "{ config, lib, modulesPath, ... }:\n"
+        "{\n"
+        '  imports = [ (modulesPath + "/installer/scan/not-detected.nix") ];\n\n'
+        "  boot = {\n"
+        "    initrd = {\n"
+        '      availableKernelModules = [ \n        "ahci"\n        "ehci_pci"\n        "nvme"\n        "sd_mod"\n'
+        '        "usb_storage"\n        "usbhid"\n        "xhci_pci"\n      ];\n'
+        "      kernelModules = [ ];\n"
+        f" {devices}"
+        "    };\n"
+        f'    kernelModules = [ "kvm-{cpu_manufacturer}" ];\n'
+        "    extraModulePackages = [ ];\n"
+        "  };\n\n"
+        "  fileSystems = {\n"
+        '    "/" = lib.mkDefault {\n      device = "root_pool/root";\n      fsType = "zfs";\n    };\n\n'
+        '    "/home" = {\n      device = "root_pool/home";\n      fsType = "zfs";\n    };\n\n'
+        '    "/var" = {\n      device = "root_pool/var";\n      fsType = "zfs";\n    };\n\n'
+        '    "/nix" = {\n      device = "root_pool/nix";\n      fsType = "zfs";\n    };\n\n'
+        '    "/boot" = {\n'
+        f'      device = "/dev/disk/by-uuid/{get_boot_drive_id(disks[0])}";\n'
+        '      fsType = "vfat";\n      options = [\n        "fmask=0077"\n'
+        '        "dmask=0077"\n      ];\n    };\n  };\n\n'
+        "  swapDevices = [ ];\n\n"
+        "  networking.useDHCP = lib.mkDefault true;\n\n"
+        '  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";\n'
+        f"  hardware.cpu.{cpu_manufacturer}.updateMicrocode = "
+        "lib.mkDefault config.hardware.enableRedistributableFirmware;\n"
+        f'  networking.hostId = "{host_id}";\n'
+        "}\n"
+    )
+
+    Path(f"{mnt_dir}/etc/nixos/hardware-configuration.nix").write_text(nix_hardware)
+
+
+def install_nixos(mnt_dir: str, disks: Sequence[str], encrypt: str | None) -> None:
+    """Install NixOS."""
+    bash_wrapper(f"mount -o X-mount.mkdir -t zfs root_pool/root {mnt_dir}")
+    bash_wrapper(f"mount -o X-mount.mkdir -t zfs root_pool/home {mnt_dir}/home")
+    bash_wrapper(f"mount -o X-mount.mkdir -t zfs root_pool/var {mnt_dir}/var")
+    bash_wrapper(f"mount -o X-mount.mkdir -t zfs root_pool/nix {mnt_dir}/nix")
+
+    for disk in disks:
+        bash_wrapper(f"mkfs.vfat -n EFI {disk}-part1")
+
+    # set up mirroring afterwards if more than one disk
+    boot_partition = (
+        f"mount -t vfat -o fmask=0077,dmask=0077,iocharset=iso8859-1,X-mount.mkdir {disks[0]}-part1 {mnt_dir}/boot"
+    )
+    bash_wrapper(boot_partition)
+
+    bash_wrapper(f"nixos-generate-config --root {mnt_dir}")
+
+    create_nix_hardware_file(mnt_dir, disks, encrypt)
+
+    run(("nixos-install", "--root", mnt_dir), check=True)
+
+
+def installer(
+    disks: Sequence[str],
+    swap_size: int,
+    reserve: int,
+    encrypt_key: str | None,
+) -> None:
+    """Main."""
+    logging.info("Starting installation")
+
+    for disk in disks:
+        partition_disk(disk, swap_size, reserve)
+
+        test = Popen(("printf", f"'{encrypt_key}'"), stdout=PIPE)
+        if encrypt_key:
+            sleep(1)
+            for command in (
+                f"cryptsetup luksFormat --type luks2 {disk}-part2 -",
+                f"cryptsetup luksOpen {disk}-part2 luks-root-pool-{disk.split('/')[-1]}-part2 -",
+            ):
+                run(command, check=True, stdin=test.stdout)
+
+    mnt_dir = "/tmp/nix_install"  # noqa: S108
+
+    Path(mnt_dir).mkdir(parents=True, exist_ok=True)
+
+    if encrypt_key:
+        pool_disks = [f"/dev/mapper/luks-root-pool-{disk.split('/')[-1]}-part2" for disk in disks]
+    else:
+        pool_disks = [f"{disk}-part2" for disk in disks]
+
+    create_zfs_pool(pool_disks, mnt_dir)
+
+    create_zfs_datasets()
+
+    install_nixos(mnt_dir, disks, encrypt_key)
+
+    logging.info("Installation complete")
+
+
+def main() -> None:
+    """Main."""
+    configure_logger("DEBUG")
+
+    state = curses.wrapper(draw_menu)
+
+    encrypt_key = getenv("ENCRYPT_KEY")
+
+    logging.info("installing_nixos")
+    logging.info(f"disks: {state.selected_device_ids}")
+    logging.info(f"swap_size: {state.swap_size}")
+    logging.info(f"reserve: {state.reserve_size}")
+    logging.info(f"encrypted: {bool(encrypt_key)}")
+
+    sleep(3)
+
+    installer(
+        disks=state.get_selected_devices(),
+        swap_size=state.swap_size,
+        reserve=state.reserve_size,
+        encrypt_key=encrypt_key,
+    )
+
+
+if __name__ == "__main__":
+    main()