nixpkgs/nixos/modules/system/boot/loader/systemd-boot/systemd-boot-builder.py

431 lines
16 KiB
Python

#! @python3@/bin/python3 -B
import argparse
import ctypes
import datetime
import errno
import glob
import os
import os.path
import re
import shutil
import subprocess
import sys
import warnings
import json
from typing import NamedTuple, Any
from dataclasses import dataclass
# These values will be replaced with actual values during the package build
EFI_SYS_MOUNT_POINT = "@efiSysMountPoint@"
BOOT_MOUNT_POINT = "@bootMountPoint@"
LOADER_CONF = f"{EFI_SYS_MOUNT_POINT}/loader/loader.conf" # Always stored on the ESP
NIXOS_DIR = "@nixosDir@"
TIMEOUT = "@timeout@"
EDITOR = "@editor@" == "1" # noqa: PLR0133
CONSOLE_MODE = "@consoleMode@"
BOOTSPEC_TOOLS = "@bootspecTools@"
DISTRO_NAME = "@distroName@"
NIX = "@nix@"
SYSTEMD = "@systemd@"
CONFIGURATION_LIMIT = int("@configurationLimit@")
REBOOT_FOR_BITLOCKER = bool("@rebootForBitlocker@")
CAN_TOUCH_EFI_VARIABLES = "@canTouchEfiVariables@"
GRACEFUL = "@graceful@"
COPY_EXTRA_FILES = "@copyExtraFiles@"
CHECK_MOUNTPOINTS = "@checkMountpoints@"
STORE_DIR = "@storeDir@"
@dataclass
class BootSpec:
init: str
initrd: str
kernel: str
kernelParams: list[str] # noqa: N815
label: str
system: str
toplevel: str
specialisations: dict[str, "BootSpec"]
sortKey: str # noqa: N815
devicetree: str | None = None # noqa: N815
initrdSecrets: str | None = None # noqa: N815
libc = ctypes.CDLL("libc.so.6")
FILE = None | int
def run(cmd: list[str], stdout: FILE = None) -> subprocess.CompletedProcess[str]:
return subprocess.run(cmd, check=True, text=True, stdout=stdout)
class SystemIdentifier(NamedTuple):
profile: str | None
generation: int
specialisation: str | None
def copy_if_not_exists(source: str, dest: str) -> None:
if not os.path.exists(dest):
shutil.copyfile(source, dest)
def generation_dir(profile: str | None, generation: int) -> str:
if profile:
return "/nix/var/nix/profiles/system-profiles/%s-%d-link" % (profile, generation)
else:
return "/nix/var/nix/profiles/system-%d-link" % (generation)
def system_dir(profile: str | None, generation: int, specialisation: str | None) -> str:
d = generation_dir(profile, generation)
if specialisation:
return os.path.join(d, "specialisation", specialisation)
else:
return d
BOOT_ENTRY = """title {title}
sort-key {sort_key}
version Generation {generation} {description}
linux {kernel}
initrd {initrd}
options {kernel_params}
"""
def generation_conf_filename(profile: str | None, generation: int, specialisation: str | None) -> str:
pieces = [
"nixos",
profile or None,
"generation",
str(generation),
f"specialisation-{specialisation}" if specialisation else None,
]
return "-".join(p for p in pieces if p) + ".conf"
def write_loader_conf(profile: str | None, generation: int, specialisation: str | None) -> None:
with open(f"{LOADER_CONF}.tmp", 'w') as f:
f.write(f"timeout {TIMEOUT}\n")
f.write("default %s\n" % generation_conf_filename(profile, generation, specialisation))
if not EDITOR:
f.write("editor 0\n")
if REBOOT_FOR_BITLOCKER:
f.write("reboot-for-bitlocker yes\n")
f.write(f"console-mode {CONSOLE_MODE}\n")
f.flush()
os.fsync(f.fileno())
os.rename(f"{LOADER_CONF}.tmp", LOADER_CONF)
def get_bootspec(profile: str | None, generation: int) -> BootSpec:
system_directory = system_dir(profile, generation, None)
boot_json_path = os.path.realpath("%s/%s" % (system_directory, "boot.json"))
if os.path.isfile(boot_json_path):
boot_json_f = open(boot_json_path, 'r')
bootspec_json = json.load(boot_json_f)
else:
boot_json_str = run(
[
f"{BOOTSPEC_TOOLS}/bin/synthesize",
"--version",
"1",
system_directory,
"/dev/stdout",
],
stdout=subprocess.PIPE,
).stdout
bootspec_json = json.loads(boot_json_str)
return bootspec_from_json(bootspec_json)
def bootspec_from_json(bootspec_json: dict[str, Any]) -> BootSpec:
specialisations = bootspec_json['org.nixos.specialisation.v1']
specialisations = {k: bootspec_from_json(v) for k, v in specialisations.items()}
systemdBootExtension = bootspec_json.get('org.nixos.systemd-boot', {})
sortKey = systemdBootExtension.get('sortKey', 'nixos')
devicetree = systemdBootExtension.get('devicetree')
return BootSpec(
**bootspec_json['org.nixos.bootspec.v1'],
specialisations=specialisations,
sortKey=sortKey,
devicetree=devicetree,
)
def copy_from_file(file: str, dry_run: bool = False) -> str:
store_file_path = os.path.realpath(file)
suffix = os.path.basename(store_file_path)
store_subdir = os.path.relpath(store_file_path, start=STORE_DIR).split(os.path.sep)[0]
efi_file_path = f"{NIXOS_DIR}/{suffix}.efi" if suffix == store_subdir else f"{NIXOS_DIR}/{store_subdir}-{suffix}.efi"
if not dry_run:
copy_if_not_exists(store_file_path, f"{BOOT_MOUNT_POINT}{efi_file_path}")
return efi_file_path
def write_entry(profile: str | None, generation: int, specialisation: str | None,
machine_id: str | None, bootspec: BootSpec, current: bool) -> None:
if specialisation:
bootspec = bootspec.specialisations[specialisation]
kernel = copy_from_file(bootspec.kernel)
initrd = copy_from_file(bootspec.initrd)
devicetree = copy_from_file(bootspec.devicetree) if bootspec.devicetree is not None else None
title = "{name}{profile}{specialisation}".format(
name=DISTRO_NAME,
profile=" [" + profile + "]" if profile else "",
specialisation=" (%s)" % specialisation if specialisation else "")
try:
if bootspec.initrdSecrets is not None:
run([bootspec.initrdSecrets, f"{BOOT_MOUNT_POINT}%s" % (initrd)])
except subprocess.CalledProcessError:
if current:
print("failed to create initrd secrets!", file=sys.stderr)
sys.exit(1)
else:
print("warning: failed to create initrd secrets "
f'for "{title} - Configuration {generation}", an older generation', file=sys.stderr)
print("note: this is normal after having removed "
"or renamed a file in `boot.initrd.secrets`", file=sys.stderr)
entry_file = f"{BOOT_MOUNT_POINT}/loader/entries/%s" % (
generation_conf_filename(profile, generation, specialisation))
tmp_path = "%s.tmp" % (entry_file)
kernel_params = "init=%s " % bootspec.init
kernel_params = kernel_params + " ".join(bootspec.kernelParams)
build_time = int(os.path.getctime(system_dir(profile, generation, specialisation)))
build_date = datetime.datetime.fromtimestamp(build_time).strftime('%F')
with open(tmp_path, 'w') as f:
f.write(BOOT_ENTRY.format(title=title,
sort_key=bootspec.sortKey,
generation=generation,
kernel=kernel,
initrd=initrd,
kernel_params=kernel_params,
description=f"{bootspec.label}, built on {build_date}"))
if machine_id is not None:
f.write("machine-id %s\n" % machine_id)
if devicetree is not None:
f.write("devicetree %s\n" % devicetree)
f.flush()
os.fsync(f.fileno())
os.rename(tmp_path, entry_file)
def get_generations(profile: str | None = None) -> list[SystemIdentifier]:
gen_list = run(
[
f"{NIX}/bin/nix-env",
"--list-generations",
"-p",
"/nix/var/nix/profiles/%s"
% ("system-profiles/" + profile if profile else "system"),
],
stdout=subprocess.PIPE,
).stdout
gen_lines = gen_list.split("\n")
gen_lines.pop()
configurationLimit = CONFIGURATION_LIMIT
configurations = [
SystemIdentifier(
profile=profile,
generation=int(line.split()[0]),
specialisation=None
)
for line in gen_lines
]
return configurations[-configurationLimit:]
def remove_old_entries(gens: list[SystemIdentifier]) -> None:
rex_profile = re.compile(r"^" + re.escape(BOOT_MOUNT_POINT) + r"/loader/entries/nixos-(.*)-generation-.*\.conf$")
rex_generation = re.compile(r"^" + re.escape(BOOT_MOUNT_POINT) + r"/loader/entries/nixos.*-generation-([0-9]+)(-specialisation-.*)?\.conf$")
known_paths = []
for gen in gens:
bootspec = get_bootspec(gen.profile, gen.generation)
known_paths.append(copy_from_file(bootspec.kernel, True))
known_paths.append(copy_from_file(bootspec.initrd, True))
for path in glob.iglob(f"{BOOT_MOUNT_POINT}/loader/entries/nixos*-generation-[1-9]*.conf"):
if rex_profile.match(path):
prof = rex_profile.sub(r"\1", path)
else:
prof = None
try:
gen_number = int(rex_generation.sub(r"\1", path))
except ValueError:
continue
if (prof, gen_number, None) not in gens:
os.unlink(path)
for path in glob.iglob(f"{BOOT_MOUNT_POINT}/{NIXOS_DIR}/*"):
if path not in known_paths and not os.path.isdir(path):
os.unlink(path)
def cleanup_esp() -> None:
for path in glob.iglob(f"{EFI_SYS_MOUNT_POINT}/loader/entries/nixos*"):
os.unlink(path)
if os.path.isdir(f"{EFI_SYS_MOUNT_POINT}/{NIXOS_DIR}"):
shutil.rmtree(f"{EFI_SYS_MOUNT_POINT}/{NIXOS_DIR}")
def get_profiles() -> list[str]:
if os.path.isdir("/nix/var/nix/profiles/system-profiles/"):
return [x
for x in os.listdir("/nix/var/nix/profiles/system-profiles/")
if not x.endswith("-link")]
else:
return []
def install_bootloader(args: argparse.Namespace) -> None:
try:
with open("/etc/machine-id") as machine_file:
machine_id = machine_file.readlines()[0].strip()
except IOError as e:
if e.errno != errno.ENOENT:
raise
machine_id = None
if os.getenv("NIXOS_INSTALL_GRUB") == "1":
warnings.warn("NIXOS_INSTALL_GRUB env var deprecated, use NIXOS_INSTALL_BOOTLOADER", DeprecationWarning)
os.environ["NIXOS_INSTALL_BOOTLOADER"] = "1"
# flags to pass to bootctl install/update
bootctl_flags = []
if BOOT_MOUNT_POINT != EFI_SYS_MOUNT_POINT:
bootctl_flags.append(f"--boot-path={BOOT_MOUNT_POINT}")
if CAN_TOUCH_EFI_VARIABLES != "1":
bootctl_flags.append("--no-variables")
if GRACEFUL == "1":
bootctl_flags.append("--graceful")
if os.getenv("NIXOS_INSTALL_BOOTLOADER") == "1":
# bootctl uses fopen() with modes "wxe" and fails if the file exists.
if os.path.exists(LOADER_CONF):
os.unlink(LOADER_CONF)
run(
[f"{SYSTEMD}/bin/bootctl", f"--esp-path={EFI_SYS_MOUNT_POINT}"]
+ bootctl_flags
+ ["install"]
)
else:
# Update bootloader to latest if needed
available_out = run(
[f"{SYSTEMD}/bin/bootctl", "--version"], stdout=subprocess.PIPE
).stdout.split()[2]
installed_out = run(
[f"{SYSTEMD}/bin/bootctl", f"--esp-path={EFI_SYS_MOUNT_POINT}", "status"],
stdout=subprocess.PIPE,
).stdout
# See status_binaries() in systemd bootctl.c for code which generates this
# Matches
# Available Boot Loaders on ESP:
# ESP: /boot (/dev/disk/by-partuuid/9b39b4c4-c48b-4ebf-bfea-a56b2395b7e0)
# File: └─/EFI/systemd/systemd-bootx64.efi (systemd-boot 255.2)
# But also:
# Available Boot Loaders on ESP:
# ESP: /boot (/dev/disk/by-partuuid/9b39b4c4-c48b-4ebf-bfea-a56b2395b7e0)
# File: ├─/EFI/systemd/HashTool.efi
# └─/EFI/systemd/systemd-bootx64.efi (systemd-boot 255.2)
installed_match = re.search(r"^\W+.*/EFI/(?:BOOT|systemd)/.*\.efi \(systemd-boot ([\d.]+[^)]*)\)$",
installed_out, re.IGNORECASE | re.MULTILINE)
available_match = re.search(r"^\((.*)\)$", available_out)
if installed_match is None:
raise Exception("Could not find any previously installed systemd-boot. If you are switching to systemd-boot from a different bootloader, you need to run `nixos-rebuild switch --install-bootloader`")
if available_match is None:
raise Exception("could not determine systemd-boot version")
installed_version = installed_match.group(1)
available_version = available_match.group(1)
if installed_version < available_version:
print("updating systemd-boot from %s to %s" % (installed_version, available_version))
run(
[f"{SYSTEMD}/bin/bootctl", f"--esp-path={EFI_SYS_MOUNT_POINT}"]
+ bootctl_flags
+ ["update"]
)
os.makedirs(f"{BOOT_MOUNT_POINT}/{NIXOS_DIR}", exist_ok=True)
os.makedirs(f"{BOOT_MOUNT_POINT}/loader/entries", exist_ok=True)
gens = get_generations()
for profile in get_profiles():
gens += get_generations(profile)
remove_old_entries(gens)
for gen in gens:
try:
bootspec = get_bootspec(gen.profile, gen.generation)
is_default = os.path.dirname(bootspec.init) == args.default_config
write_entry(*gen, machine_id, bootspec, current=is_default)
for specialisation in bootspec.specialisations.keys():
write_entry(gen.profile, gen.generation, specialisation, machine_id, bootspec, current=is_default)
if is_default:
write_loader_conf(*gen)
except OSError as e:
# See https://github.com/NixOS/nixpkgs/issues/114552
if e.errno == errno.EINVAL:
profile = f"profile '{gen.profile}'" if gen.profile else "default profile"
print("ignoring {} in the list of boot entries because of the following error:\n{}".format(profile, e), file=sys.stderr)
else:
raise e
if BOOT_MOUNT_POINT != EFI_SYS_MOUNT_POINT:
# Cleanup any entries in ESP if xbootldrMountPoint is set.
# If the user later unsets xbootldrMountPoint, entries in XBOOTLDR will not be cleaned up
# automatically, as we don't have information about the mount point anymore.
cleanup_esp()
for root, _, files in os.walk(f"{BOOT_MOUNT_POINT}/{NIXOS_DIR}/.extra-files", topdown=False):
relative_root = root.removeprefix(f"{BOOT_MOUNT_POINT}/{NIXOS_DIR}/.extra-files").removeprefix("/")
actual_root = os.path.join(f"{BOOT_MOUNT_POINT}", relative_root)
for file in files:
actual_file = os.path.join(actual_root, file)
if os.path.exists(actual_file):
os.unlink(actual_file)
os.unlink(os.path.join(root, file))
if not len(os.listdir(actual_root)):
os.rmdir(actual_root)
os.rmdir(root)
os.makedirs(f"{BOOT_MOUNT_POINT}/{NIXOS_DIR}/.extra-files", exist_ok=True)
run([COPY_EXTRA_FILES])
def main() -> None:
parser = argparse.ArgumentParser(description=f"Update {DISTRO_NAME}-related systemd-boot files")
parser.add_argument('default_config', metavar='DEFAULT-CONFIG', help=f"The default {DISTRO_NAME} config to boot")
args = parser.parse_args()
run([CHECK_MOUNTPOINTS])
try:
install_bootloader(args)
finally:
# Since fat32 provides little recovery facilities after a crash,
# it can leave the system in an unbootable state, when a crash/outage
# happens shortly after an update. To decrease the likelihood of this
# event sync the efi filesystem after each update.
rc = libc.syncfs(os.open(f"{BOOT_MOUNT_POINT}", os.O_RDONLY))
if rc != 0:
print(f"could not sync {BOOT_MOUNT_POINT}: {os.strerror(rc)}", file=sys.stderr)
if BOOT_MOUNT_POINT != EFI_SYS_MOUNT_POINT:
rc = libc.syncfs(os.open(EFI_SYS_MOUNT_POINT, os.O_RDONLY))
if rc != 0:
print(f"could not sync {EFI_SYS_MOUNT_POINT}: {os.strerror(rc)}", file=sys.stderr)
if __name__ == '__main__':
main()