43 lines
1.1 KiB
Markdown
43 lines
1.1 KiB
Markdown
# netboot.nix: 15 second netboot iterations
|
|
|
|
## How to Use
|
|
|
|
1. set up recursive nix on your builder (see below)
|
|
2. add `quickly.nix` to your system's imports, like in
|
|
`./config/base.nix`
|
|
3. then build your iPXE boot directory:
|
|
|
|
```
|
|
$ nix-build '<nixpkgs/nixos>' -I nixos-config=./config/base.nix -A config.system.build.ipxeBootDir
|
|
```
|
|
|
|
4. boot off of `./result/netboot.ipxe`.
|
|
|
|
The initial build may take a few minutes, but subsequent builds will
|
|
only take a few seconds.
|
|
|
|
## Setting up recursive nix
|
|
|
|
Setting up recursive Nix requires support on the build machine:
|
|
|
|
```nix
|
|
{ pkgs, ... }: {
|
|
nix = {
|
|
package = pkgs.nixUnstable;
|
|
systemFeatures = [ "recursive-nix" "kvm" "nixos-test" ];
|
|
extraOptions = ''
|
|
experimental-features = recursive-nix
|
|
'';
|
|
};
|
|
}
|
|
```
|
|
|
|
## How it works
|
|
`./quickly.nix` uses recursive Nix to build the initrd and squashfs
|
|
filesystems more quickly, allowing for faster iteration of images.
|
|
Initial testing reduced build time from 5-10 minutes per image to
|
|
15-30 seconds.
|
|
|
|
The `./config/build.sh` test is able to build an incremental
|
|
netboot image in just 12 seconds, and the initrd is not rebuilt.
|