The nix store more-or-less requires o+rx on all parent directories.
This is primarily because nix runs builders in a uid/gid mapped
user-namespace, and those builders have to be able to operate on the nix
store.
This check is especially helpful because nix does not produce a helpful
error on its own (rather, creating directories and such works, it's not
until 'mount --bind' that it gets an EACCES).
Helps users who run into this opaque error, such as in #67465.
Possibly fixes that issue if bad permissions were the only cause.
'nix build' is an experimental command so we shouldn't use it
yet. (nixos-rebuild also uses 'nix', but only when using flakes, which
are themselves an experimental feature.)
nix build should store it's temporary files on target filesystem.
This should fix 'No space left on device' on systems
with low amount of RAM when there is a need to build something
like Linux kernel
When installing a fresh NixOS system it occasionally happens that you
encounter issues that are rather hard to track down since
`nixos-install(8)` doesn't provide any debugging flags.
This patch adds `-L` to force `nix build` to display the build-log on
stderr and `-v` to increase the log-level of Nix.
If setting a root password using the `passwd` call in the
`nixos-install` script fails, it should be explained how set it manually
to ensure that nobody gets accidentally locked out of the system.
This reverts commit 10addad603, reversing
changes made to 7786575c6c.
NixOS scripts should be kept in the NixOS source tree, not in
pkgs. Moving them around is just confusing and creates unnecessary
code/history churn.
Move all the nixos-* scripts from the nixos distribution as real
packages in the pkgs/ package set.
This allows non-nixos users to run the script as well. For example,
deploying a remote machine with:
nixos-rebuild --target-host root@hostname --build-host root@hostname
The system variable is used from the (possibly polluted) shell
environment.
This causes nixos-install to fail in a nix-shell because the system
shell variable is automatically set to the current system (e.g.
x86_64-linux).
The use of Nix 2.0 significantly simplifies the installer, since we
can just pass a different store URI (--store /mnt) - it's no longer
needed to set up a chroot environment for the build, and to bootstrap
Nix into the chroot.
Also, commands that need to run in the installation (namely boot
loader installation and setting a root password) are now executed
using nixos-enter.
This also removes the need for nixos-prepare-root since any required
initialisation is done by Nix or by the activation script.
The key distinction I'm drawing is that there's a component that deals
with the store of the machine being built, and another component for
the store building it. The inner part of it assumes nothing from the
builder (doesn't need chroot or root powers) so it can run comfortably
inside a Nix build, as well as nixos-rebuild. I have some upcoming work
that will use that to significantly speed up and streamline image builds
for NixOS, especially on virtualized hosts like EC2, but it's also a
reasonable speedup on native hosts.
Since some changes to the setuid wrappers, there is a symlink involved
and it doesn't resolve correctly inside the chroot. Do the check inside
the chroot to make it work again.
This partially reverts commit 0aa7520670.
Fine for rsync to be in system path but we still need the explicit path
in nixos-install in case it is invoked from non-NixOS systems and also
to fix OVA test failure
See also 0aa7520670
cc @edolstra
This reverts commit 582313bafe.
Removing rsync is actually pointless because nixos-install depends on
it. So if it's part of the system closure, we may as well provide it
to users.
Probably with the next Nix release we can drop the use of rsync and
use "nix copy" instead.
Before this commit updating /var/setuid-wrappers/ folder introduced
a small window where NixOS activation scripts could be terminated
and resulted into empty /var/setuid-wrappers/ folder.
That's very unfortunate because one might lose sudo binary.
Instead we use two atomic operations mv and ln (as described in
https://axialcorps.com/2013/07/03/atomically-replacing-files-and-directories/)
to achieve atomicity.
Since /var/setuid-wrappers is not a directory anymore, tmpfs mountpoints
were removed in installation scripts and in boot process.
Tested:
- upgrade /var/setuid-wrappers/ from folder to a symlink
- make sure /run/setuid-wrappers-dirs/ legacy symlink is really deleted
- Replace hand-rolled version of nixos-install in make-disk-image by an
actual call to nixos-install
- Required a few cleanups of nixos-install
- nixos-install invokes an activation script which the hand-rolled version
in make-disk-image did not do. We remove /etc/machine-id as that's
a host-specific, impure, output of the activation script
Testing:
nix-build '<nixpkgs/nixos/release.nix>' -A tests.installer.simple passes
Also tried generating an image with:
nix-build -E 'let
pkgs = import <nixpkgs> {};
lib = pkgs.lib;
nixos = import <nixpkgs/nixos> {
configuration = {
fileSystems."/".device = "/dev/disk/by-label/nixos";
boot.loader.grub.devices = [ "/dev/sda" ];
boot.loader.grub.extraEntries = '"''"'
menuentry "Ubuntu" {
insmod ext2
search --set=root --label ubuntu
configfile /boot/grub/grub.cfg
}
'"''"';
};
};
in import <nixpkgs/nixos/lib/make-disk-image.nix> {
inherit pkgs lib;
config = nixos.config;
diskSize = 2000;
partitioned = false;
installBootLoader = false;
}'
Then installed the image:
$ sudo df if=./result/nixos.img of=/dev/sdaX bs=1M
$ sudo resize2fs /dev/disk/by-label/nixos
$ sudo mount /dev/disk/by-label/nixos /mnt
$ sudo mount --rbind /proc /mnt/proc
$ sudo mount --rbind /dev /mnt/dev
$ sudo chroot /mnt /nix/var/nix/profiles/system/bin/switch-to-configuration boot
[ … optionally do something about passwords … ]
and successfully rebooted to that image.
Was doing all this from inside a Ubuntu VM with a single user nix install.
- Fix --no-bootloader which didn't do what it advertised
- Hardcode nixbld GID so that systems which do not have a nixbld user
can still run nixos-install (only with --closure since they can't
build anything)
- Cleanup: get rid of NIX_CONF_DIR(=/tmp)/nix.conf and pass arguments instead
- Cleanup: don't assume that the target system has '<nixpkgs/nixos>' or
'<nixos-config>' to see if config.users.mutableUsers. Instead check if
/var/setuid-wrappers/passwd is there
Installing NixOS now works from a Ubuntu host (using --closure).
nix-build -A tests.installer.simple '<nixpkgs/nixos/release.nix>' succeeds ✓
