# nixos-anywhere and disko

This is an example repository for nixos-anywhere and disko.

Inspiration:
* Introductory presentation: https://pad.lassul.us/cccamp-workshop
* https://github.com/numtide/nixos-anywhere-examples

Manuals:
* disko reference: https://github.com/nix-community/disko/blob/master/docs/reference.md
* nixos-anywhere reference: https://github.com/nix-community/nixos-anywhere/blob/main/docs/reference.md

## Build installer ISO with passwordless SSH

```shell
nix-build '<nixpkgs/nixos>' -A config.system.build.isoImage -I nixos-config=iso.nix
# aarch64 ISO (requires emulation)
#nix-build '<nixpkgs/nixos>' -A config.system.build.isoImage -I nixos-config=iso.nix --argstr system aarch64-linux

ls result/iso/*.iso
```

## Hardware Configuration

Boot the target machine into NixOS live ISO. Then execute the following, ideally while connected via SSH:

```shell
nixos-generate-config --no-filesystems --root /mnt
cat /mnt/etc/nixos/hardware-configuration.nix
```

Save the output to a new file in [./hardware-configs/](./hardware-configs/). In [./flake.nix](./flake.nix) replace `./hardware-configs/yodaHP.nix` with it.

Note: The hardware configuration should not contain any `fileSystems.<name>` options as these are generated based on your disko configuration.

## Installation

To run the interactive vm test run:

```shell
nix --extra-experimental-features nix-command --extra-experimental-features flakes \
  run github:numtide/nixos-anywhere -- -f '.#mysystem' --vm-test
```

To install on remote target machine:

```shell
# yodaHP
nix --extra-experimental-features nix-command --extra-experimental-features flakes \
  run github:numtide/nixos-anywhere -- --flake '.#mysystem' -p 22 root@192.168.178.106
```

To install on remote target machine **and** print the SSH fingerprint of the new system. If no encrypted disks are set up, the disk password can be left empty:

```shell
# yodaHP
./install-helper.sh 22 root@192.168.178.106
```

## Updating dependencies

Recreate the lock file (i.e. update all inputs) and commit the new lock file:

```shell
nix --extra-experimental-features nix-command --extra-experimental-features flakes \
  flake update --commit-lock-file
```

## TODOs

- Hetzner Cloud example: https://github.com/numtide/nixos-anywhere-examples/blob/main/flake.nix