pyrox.dev
1#! @python3@/bin/python3 -B
2import argparse
3import shutil
4import os
5import sys
6import errno
7import subprocess
8import glob
9import tempfile
10import errno
11import warnings
12import ctypes
13libc = ctypes.CDLL("libc.so.6")
14import re
15
16def copy_if_not_exists(source, dest):
17 if not os.path.exists(dest):
18 shutil.copyfile(source, dest)
19
20def system_dir(profile, generation):
21 if profile:
22 return "/nix/var/nix/profiles/system-profiles/%s-%d-link" % (profile, generation)
23 else:
24 return "/nix/var/nix/profiles/system-%d-link" % (generation)
25
26BOOT_ENTRY = """title NixOS{profile}
27version Generation {generation}
28linux {kernel}
29initrd {initrd}
30options {kernel_params}
31"""
32
33def write_loader_conf(profile, generation):
34 with open("@efiSysMountPoint@/loader/loader.conf.tmp", 'w') as f:
35 if "@timeout@" != "":
36 f.write("timeout @timeout@\n")
37 if profile:
38 f.write("default nixos-%s-generation-%d\n" % (profile, generation))
39 else:
40 f.write("default nixos-generation-%d\n" % (generation))
41 if not @editor@:
42 f.write("editor 0");
43 os.rename("@efiSysMountPoint@/loader/loader.conf.tmp", "@efiSysMountPoint@/loader/loader.conf")
44
45def profile_path(profile, generation, name):
46 return os.readlink("%s/%s" % (system_dir(profile, generation), name))
47
48def copy_from_profile(profile, generation, name, dry_run=False):
49 store_file_path = profile_path(profile, generation, name)
50 suffix = os.path.basename(store_file_path)
51 store_dir = os.path.basename(os.path.dirname(store_file_path))
52 efi_file_path = "/efi/nixos/%s-%s.efi" % (store_dir, suffix)
53 if not dry_run:
54 copy_if_not_exists(store_file_path, "@efiSysMountPoint@%s" % (efi_file_path))
55 return efi_file_path
56
57def write_entry(profile, generation, machine_id):
58 kernel = copy_from_profile(profile, generation, "kernel")
59 initrd = copy_from_profile(profile, generation, "initrd")
60 try:
61 append_initrd_secrets = profile_path(profile, generation, "append-initrd-secrets")
62 subprocess.check_call([append_initrd_secrets, "@efiSysMountPoint@%s" % (initrd)])
63 except FileNotFoundError:
64 pass
65 if profile:
66 entry_file = "@efiSysMountPoint@/loader/entries/nixos-%s-generation-%d.conf" % (profile, generation)
67 else:
68 entry_file = "@efiSysMountPoint@/loader/entries/nixos-generation-%d.conf" % (generation)
69 generation_dir = os.readlink(system_dir(profile, generation))
70 tmp_path = "%s.tmp" % (entry_file)
71 kernel_params = "systemConfig=%s init=%s/init " % (generation_dir, generation_dir)
72 with open("%s/kernel-params" % (generation_dir)) as params_file:
73 kernel_params = kernel_params + params_file.read()
74 with open(tmp_path, 'w') as f:
75 f.write(BOOT_ENTRY.format(profile=" [" + profile + "]" if profile else "",
76 generation=generation,
77 kernel=kernel,
78 initrd=initrd,
79 kernel_params=kernel_params))
80 if machine_id is not None:
81 f.write("machine-id %s\n" % machine_id)
82 os.rename(tmp_path, entry_file)
83
84def mkdir_p(path):
85 try:
86 os.makedirs(path)
87 except OSError as e:
88 if e.errno != errno.EEXIST or not os.path.isdir(path):
89 raise
90
91def get_generations(profile=None):
92 gen_list = subprocess.check_output([
93 "@nix@/bin/nix-env",
94 "--list-generations",
95 "-p",
96 "/nix/var/nix/profiles/%s" % ("system-profiles/" + profile if profile else "system"),
97 "--option", "build-users-group", ""],
98 universal_newlines=True)
99 gen_lines = gen_list.split('\n')
100 gen_lines.pop()
101 return [ (profile, int(line.split()[0])) for line in gen_lines ]
102
103def remove_old_entries(gens):
104 rex_profile = re.compile("^@efiSysMountPoint@/loader/entries/nixos-(.*)-generation-.*\.conf$")
105 rex_generation = re.compile("^@efiSysMountPoint@/loader/entries/nixos.*-generation-(.*)\.conf$")
106 known_paths = []
107 for gen in gens:
108 known_paths.append(copy_from_profile(*gen, "kernel", True))
109 known_paths.append(copy_from_profile(*gen, "initrd", True))
110 for path in glob.iglob("@efiSysMountPoint@/loader/entries/nixos*-generation-[1-9]*.conf"):
111 try:
112 if rex_profile.match(path):
113 prof = rex_profile.sub(r"\1", path)
114 else:
115 prof = "system"
116 gen = int(rex_generation.sub(r"\1", path))
117 if not (prof, gen) in gens:
118 os.unlink(path)
119 except ValueError:
120 pass
121 for path in glob.iglob("@efiSysMountPoint@/efi/nixos/*"):
122 if not path in known_paths:
123 os.unlink(path)
124
125def get_profiles():
126 if os.path.isdir("/nix/var/nix/profiles/system-profiles/"):
127 return [x
128 for x in os.listdir("/nix/var/nix/profiles/system-profiles/")
129 if not x.endswith("-link")]
130 else:
131 return []
132
133def main():
134 parser = argparse.ArgumentParser(description='Update NixOS-related systemd-boot files')
135 parser.add_argument('default_config', metavar='DEFAULT-CONFIG', help='The default NixOS config to boot')
136 args = parser.parse_args()
137
138 try:
139 with open("/etc/machine-id") as machine_file:
140 machine_id = machine_file.readlines()[0]
141 except IOError as e:
142 if e.errno != errno.ENOENT:
143 raise
144 # Since systemd version 232 a machine ID is required and it might not
145 # be there on newly installed systems, so let's generate one so that
146 # bootctl can find it and we can also pass it to write_entry() later.
147 cmd = ["@systemd@/bin/systemd-machine-id-setup", "--print"]
148 machine_id = subprocess.check_output(cmd).rstrip()
149
150 if os.getenv("NIXOS_INSTALL_GRUB") == "1":
151 warnings.warn("NIXOS_INSTALL_GRUB env var deprecated, use NIXOS_INSTALL_BOOTLOADER", DeprecationWarning)
152 os.environ["NIXOS_INSTALL_BOOTLOADER"] = "1"
153
154 if os.getenv("NIXOS_INSTALL_BOOTLOADER") == "1":
155 # bootctl uses fopen() with modes "wxe" and fails if the file exists.
156 if os.path.exists("@efiSysMountPoint@/loader/loader.conf"):
157 os.unlink("@efiSysMountPoint@/loader/loader.conf")
158
159 if "@canTouchEfiVariables@" == "1":
160 subprocess.check_call(["@systemd@/bin/bootctl", "--path=@efiSysMountPoint@", "install"])
161 else:
162 subprocess.check_call(["@systemd@/bin/bootctl", "--path=@efiSysMountPoint@", "--no-variables", "install"])
163
164 mkdir_p("@efiSysMountPoint@/efi/nixos")
165 mkdir_p("@efiSysMountPoint@/loader/entries")
166
167 gens = get_generations()
168 for profile in get_profiles():
169 gens += get_generations(profile)
170 remove_old_entries(gens)
171 for gen in gens:
172 write_entry(*gen, machine_id)
173 if os.readlink(system_dir(*gen)) == args.default_config:
174 write_loader_conf(*gen)
175
176 # Since fat32 provides little recovery facilities after a crash,
177 # it can leave the system in an unbootable state, when a crash/outage
178 # happens shortly after an update. To decrease the likelihood of this
179 # event sync the efi filesystem after each update.
180 rc = libc.syncfs(os.open("@efiSysMountPoint@", os.O_RDONLY))
181 if rc != 0:
182 print("could not sync @efiSysMountPoint@: {}".format(os.strerror(rc)), file=sys.stderr)
183
184if __name__ == '__main__':
185 main()