2021-06-10 08:10:06 +02:00
# nixos-images
2022-09-05 08:58:49 +02:00
Automatically weekly updated images for NixOS. This project is intended to extend the images created by hydra.nixos.org.
We are currently creating the images listed below:
2021-06-10 10:43:44 +02:00
2022-09-05 08:58:49 +02:00
## Netboot images
2021-06-10 10:43:44 +02:00
2022-09-05 08:58:49 +02:00
You can boot the netboot image using this [ipxe script ](https://github.com/nix-community/nixos-images/releases/download/nixos-unstable/netboot-x86_64-linux.ipxe ).
It consists of the [kernel image ](https://github.com/nix-community/nixos-images/releases/download/nixos-unstable/bzImage-x86_64-linux ) and [initrd ](https://github.com/nix-community/nixos-images/releases/download/nixos-unstable/bzImage-x86_64-linux ).
## Kexec tarballs
Kexec is a mechanism in Linux to load a new kernel from a running Linux to
2022-09-05 09:06:38 +02:00
replace the current kernel. This is useful for booting the Nixos installer from
2022-09-05 08:58:49 +02:00
existing Linux distributions, such as server provider that do not offer a NixOS
2022-09-20 08:34:00 +02:00
option. After running kexec, the NixOS installer exists only in memory. At the
2023-05-07 21:44:20 +02:00
time of writing, this requires at least 1.5GB of physical RAM (swap does not
2022-09-20 08:34:00 +02:00
count) in the system. If not enough RAM is available, the initrd cannot be
loaded. Because the NixOS runs only in RAM, users can reformat all the system's
discs to prepare for a new NixOS installation.
2022-09-05 08:58:49 +02:00
2022-09-05 09:03:21 +02:00
It can be booted as follows by running these commands as root:
2022-09-05 08:58:49 +02:00
```
2023-05-07 21:44:20 +02:00
curl -L https://github.com/nix-community/nixos-images/releases/download/nixos-unstable/nixos-kexec-installer-noninteractive-x86_64-linux.tar.gz | tar -xzf- -C /root
2022-09-05 08:58:49 +02:00
/root/kexec/run
```
2022-11-27 20:11:19 +01:00
The kexec installer comes with the following features:
- Re-uses ssh host keys from the sshd to not break `.ssh/known_hosts`
- Authorized ssh keys are read from `/root/.ssh/authorized_keys` , `/root/.ssh/authorized_keys2` and `/etc/ssh/authorized_keys.d/root`
2022-12-16 15:02:37 +01:00
- (experimental, only tested for nixos-unstable) Static ip addresses and routes
are restored after reboot. Interface that had dynamic addresses before are
configured with DHCP and to accept prefixes from ipv6 router advertisment
2022-11-27 20:11:19 +01:00
2022-11-25 10:43:14 +01:00
The actual kexec happens with a slight delay (6s). This allows for easier
integration into automated nixos installation scripts, since you can cleanly
2023-05-07 21:44:20 +02:00
disconnect from the running machine before the kexec takes place. The tarball
2022-11-25 10:43:14 +01:00
is also designed to be run from NixOS, which can be useful for new installations
