systemd-boot: Make sure /etc/machine-id exists

This leads to the following error when trying to install a new machine
where the machine ID wasn't yet initialized during boot:

Failed to get machine did: No such file or directory

In addition this was also detected by the simpleUefiGummiboot installer
test.

So let's generate a fallback machine ID by using
systemd-machine-id-setup before actually running bootctl.

Tested this by running the installer.simpleUefiGummiboot test, it still
fails but not because of the machine ID.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Cc: @edolstra, @shlevy, @mic92
Fixes: #22561

1 files changed, 12 insertions, 7 deletions

diff --git a/nixos/modules/system/boot/loader/systemd-boot/systemd-boot-builder.py b/nixos/modules/system/boot/loader/systemd-boot/systemd-boot-builder.py
index b91d64bb0a7..9218e1dc8a7 100644
--- a/nixos/modules/system/boot/loader/systemd-boot/systemd-boot-builder.py
+++ b/nixos/modules/system/boot/loader/systemd-boot/systemd-boot-builder.py
@@ -101,6 +101,18 @@ def main():
     parser.add_argument('default_config', metavar='DEFAULT-CONFIG', help='The default NixOS config to boot')
     args = parser.parse_args()
 
+    try:
+        with open("/etc/machine-id") as machine_file:
+            machine_id = machine_file.readlines()[0]
+    except IOError as e:
+        if e.errno != errno.ENOENT:
+            raise
+        # Since systemd version 232 a machine ID is required and it might not
+        # be there on newly installed systems, so let's generate one so that
+        # bootctl can find it and we can also pass it to write_entry() later.
+        cmd = ["@systemd@/bin/systemd-machine-id-setup", "--print"]
+        machine_id = subprocess.check_output(cmd).rstrip()
+
     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"
@@ -113,13 +125,6 @@ def main():
 
     mkdir_p("@efiSysMountPoint@/efi/nixos")
     mkdir_p("@efiSysMountPoint@/loader/entries")
-    try:
-        with open("/etc/machine-id") as machine_file:
-            machine_id = machine_file.readlines()[0]
-    except IOError as e:
-        if e.errno != errno.ENOENT:
-            raise
-        machine_id = None
 
     gens = get_generations("system")
     remove_old_entries(gens)