infra/devdoc/hosts.md

## SSH config:

You will need to set your admin username if it doesn't match your local username.

```
Host *.nix-community.org
  User <youradminusername>
```

## Deployment commands:

```console
$ ./inv deploy
```

## Install/Fix system from Hetzner recovery mode

1. Copy your ssh key to the recovery system so that the kexec image can re-use it.

```console
yourmachine> ssh-copy-id root@build0X.nix-community.org
```

2. Download and boot into kexec-image:

```console
$ curl -L https://github.com/nix-community/nixos-images/releases/download/nixos-unstable/nixos-kexec-installer-x86_64-linux.tar.gz | tar -xzf- -C /root
$ /root/kexec/run
```

## Fix up broken installations with disko-install

Disko install allows to update nixos configuration with out re-formatting, if the `--mode` parameter is set to `mount`. This assumes that the file system is still intact. `--disk` may need to be adjusted according to the concrete disko configuration. i.e. disks during installation may have different names than later in the recovery system. Use lsblk or `/dev/disk/by-partlabel` to reason about which disk is which.

```console
$ ls -la /dev/disk/by-partlabel/
total 0
drwxr-xr-x  2 root root 120 Jul 11 21:45 .
drwxr-xr-x 11 root root 220 Jul 11 21:45 ..
lrwxrwxrwx  1 root root  15 Jul 11 21:45 disk-nvme0n1-boot -> ../../nvme1n1p1
lrwxrwxrwx  1 root root  15 Jul 11 21:45 disk-nvme0n1-ESP -> ../../nvme1n1p2
lrwxrwxrwx  1 root root  15 Jul 11 21:45 disk-nvme0n1-zfs -> ../../nvme1n1p3
lrwxrwxrwx  1 root root  15 Jul 11 21:45 disk-nvme1n1-zfs -> ../../nvme0n1p1
$ lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
loop0         7:0    0 310.8M  0 loop /nix/.ro-store
loop1         7:1    0    36K  0 loop
nvme1n1     259:0    0   1.7T  0 disk
├─nvme1n1p1 259:3    0     1M  0 part
├─nvme1n1p2 259:4    0     1G  0 part
└─nvme1n1p3 259:5    0   1.7T  0 part
nvme0n1     259:1    0   1.7T  0 disk
└─nvme0n1p1 259:2    0   1.7T  0 part
$ nix run github:nix-community/disko#disko-install -- --mode mount --flake github:nix-community/infra#build02 --disk nvme0n1 /dev/nvme1n1 --disk nvme1n1 /dev/nvme0n1
```

### Debug VM

You can start a vm from the rescue system in order to debug the boot:

```console
$ nix-shell -p qemu_kvm --run 'qemu-kvm -m 10G -hda /dev/sda -hdb /dev/sdb -curses -cpu host -enable-kvm'
```