Getting Started: Physical Machine Target

• Nix on your Setup Machine (unless you're using NixOS)

• An SSH key on your setup machine. See Create an SSH key if you don't have one yet.

• Git (Optional). Clan uses Git internally, but you can optionally install it to make your own use of it. You can find installation instructions here.

Terminology

Setup machine This is the computer you'll be working from to set up and manage your other machines.

Target machine This is one (or more) computers that you'll be managing. These can be either physical or virtual machines.

Machine configuration Clan's own internal representation of a target machine.

1. Create the clan

Start by creating a new clan:

nix run "https://git.clan.lol/clan/clan-core/archive/main.tar.gz#clan-cli" --refresh -- init

and enter a name for it, e.g. MY-CLAN-1, followed by a domain, e.g. myclan1.lol. (This does not have to be an actual registered domain.)

Change to the new folder:

cd MY-CLAN-1

You will see a message about direnv needing approval to run. Type:

direnv allow

2. Create a machine configuration

Next create a machine configuration, which adds a description of a machine to your inventory. For this example, call it test-machine, by typing:

clan machines create test-machine

Open clan.nix, and find the inventory.machines line; add the following immediately after it. (You will add the IP address later in this guide.)

inventory.machines = { # FIND THIS LINE, ADD THE FOLLOWING
    test-machine = {
        deploy.targetHost = "root@<IP-ADDRESS>"; # REPLACE WITH YOUR MACHINE'S IP ADDRESS; keep "root@"
        tags = [ ];
    };

Test it out:

clan machines list

3. Add your allowed keys

Next, add your public key to the allowed keys. You can find it by running:

cat ~/.ssh/id_ed25519.pub

Open clan.nix, and replace PASTE_YOUR_KEY_HERE with the contents of the id_ed25519.pub file:

"admin-machine-1" = "PASTE_YOUR_KEY_HERE";

Verify that your configuration is valid:

clan show

4. Enable WiFi on Target Machine (Optional)

If you plan to manage your physical machine through WiFi, you will need to add the following to your clan.nix file under inventory.instances:

  inventory.instances = {
    wifi = {
      roles.default.machines."test-machine" = {
        settings.networks.home = { };
      };
    };

This will allow WiFi to be used on the target machine after installation.

5. Create an Installer USB Drive

Obtain a USB drive with at least 1.5 GB total space.

First, download the installer ISO image for your target machine's architecture:

For x86_64 machines:

wget https://github.com/nix-community/nixos-images/releases/download/nixos-25.11/nixos-installer-x86_64-linux.iso

For aarch64 (ARM) machines:

wget https://github.com/nix-community/nixos-images/releases/download/nixos-25.11/nixos-installer-aarch64-linux.iso

Insert the USB drive into your setup computer. Determine its block device name by typing:

lsblk

You will see output similar to this; look under the SIZE column to find the entry that matches the USB drive's size. (It will likely be sda or sdb):

NAME                                          MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINTS
sdb                                             8:0    1 117,2G  0 disk
└─sdb1                                          8:1    1 117,2G  0 part  /run/media/qubasa/INTENSO
nvme0n1                                       259:0    0   1,8T  0 disk
├─nvme0n1p1                                   259:1    0   512M  0 part  /boot
└─nvme0n1p2                                   259:2    0   1,8T  0 part
    └─luks-f7600028-9d83-4967-84bc-dd2f498bc486 254:0    0   1,8T  0 crypt /nix/store

Unmount the device; replace sdb below with your own identifier, and repeat for each mounted partition, for example:

sudo umount /dev/sdb1
sudo umount /dev/sdb2
sudo umount /dev/sdb3

Now flash the ISO to the USB drive using dd. Replace <USB_DEVICE> with your device name (e.g. sdb) and <ISO_FILE> with the downloaded filename:

sudo dd if=<ISO_FILE> of=/dev/<USB_DEVICE> bs=4M status=progress conv=fsync

For example:

sudo dd if=nixos-installer-x86_64-linux.iso of=/dev/sdb bs=4M status=progress conv=fsync

6. Plug in and Run the Installer

You now have an installer USB that you can remove and plug into the target computer and boot to the USB drive.

Once booted, you will see a QR code and text similar to this:

│ ┌─────────────────────────────────────────────────────────────────────────────────┐ │
│ │Local network addresses:                                                         │ │
│ │enp1s0           UP    192.168.000.001/24 metric 1024 fe80::21e:6ff:fe45:3c92/64 │ │
│ │enp2s0           DOWN                                                            │ │
│ │wlan0            DOWN # connect to wlan (3)                                      │ │
│ │Onion address: 6evxy5yhzytwpnhc2vpscrbti3iktxdhpnf6yim6bbs25p4v6beemzyd.onion    │ │
│ │Multicast DNS: nixos-installer.local                                             │ │
│ └─────────────────────────────────────────────────────────────────────────────────┘ │
│ Press 'Ctrl-C' for console access

Take note of the IP address displayed above, either for wireless or lan, depending on how you connected. Then return to the setup machine and update this line that you added to the clan.nix file earlier; add in the actual IP address:

deploy.targetHost = "root@<IP-ADDRESS>"; # REPLACE WITH YOUR MACHINE'S IP ADDRESS;

7. Enabling Wireless During Installation

To enable wireless during installation, press Ctrl+C to drop to a command-line prompt, and type:

nmtui

In the GUI that opens:

1. Press Down-Arrow to get to Activate a Connection and press Enter.
2. In the list that appears, arrow-down to the same network your setup computer is connected to.
3. Press the Right Arrow to highlight the "\<Activate>" button.
4. Enter the password when asked, or push the button on the router.
5. Press Esc, then arrow-down to Quit.

You should now be online. You can test it by:

ping www.clan.lol

Press Ctrl+D to return to the installer app, and note the IP address, and add it to the clan.nix file as described earlier.

8. Get Hardware Configuration

Now gather the hardware configuration from the target machine:

clan machines init-hardware-config test-machine --target-host root@<IP-ADDRESS>

Replace <IP-ADDRESS> with the IP address of your target machine.

You will be asked to enter "y" to proceed.

9. Add a disk configuration

Next, configure a disk for the target machine. You'll run this command in two steps; first, type it like so:

clan templates apply disk single-disk test-machine --set mainDisk ""

This will generate an error; note the disk ID it prints out (typically starting with /dev/disk/by-id), and add it inside the quotes, e.g.:

clan templates apply disk single-disk test-machine --set mainDisk "/dev/disk/by-id/..."

10. Install

Install NixOS on the target machine by typing:

clan machines install test-machine --target-host root@<IP-ADDRESS>

Replace <IP-ADDRESS> with the target machine's IP address as before.

You will be asked whether you want to install — type y. You will also be prompted for WiFi credentials (use the same network your setup machine is on) and a root password (you can either create one or let Clan assign a random one).

If you get an error about Sandboxing

If you get an error regarding sandboxing not being available, type the following to disable sandboxing, and then run the above command again:

clan vars generate test-machine --no-sandbox

You may need to re-enter the WiFi credentials and root password. Then run the install again:

clan machines install test-machine --target-host <USER>@<IP-ADDRESS>

After completion, remove the USB drive before the machine reboots. You may need to reboot manually.

11. Test Connection

Now you can try connecting to the remote machine:

clan ssh test-machine

You'll quite likely get an error at first regarding the host identification. It should include a line to type to remove the old ID; paste the line you're shown, which will look similar to this:

  ssh-keygen -f '/home/user/.ssh/known_hosts' -R '<IP-ADDRESS>'

Then try again:

clan ssh test-machine

You should connect and see the prompt:

[root@test-machine:~]#

Practice: Install Some Packages

Now let's look at how you can use Clan to install and remove packages on a target machine.

For this demonstration we'll add three command-line packages: bat, btop, and tldr. In clan.nix, under inventory.instances, add the following lines:

  inventory.instances = {
    packages = {
      roles.default.machines."test-machine".settings = {
        packages = [ "bat" "btop" "tldr" ];
      };
    };
    # ... existing wifi service ...
  };

This declares that the three packages will be present on the machine. To install them, type:

clan machines update test-machine

Now ssh into the machine, and they should be present:

which bat
which btop
which tldr

Each will show a path to the binary file:

/run/current-system/sw/bin/bat
/run/current-system/sw/bin/btop
/run/current-system/sw/bin/tldr

Next, let's remove one of the three packages. The packages portion of clan.nix declares what additional packages should exist; by removing one, Nix will remove that package. Remove the "tldr" from the list:

        packages = [ "bat" "btop" ];

and run the update again:

clan machines update test-machine

Now when you check which tldr, it should show that it's not in the path:

which tldr
which: no tldr in (/run/wrappers/bin:/root/.nix-profile/bin:/nix/profile/bin:/root/.local/state/nix/profile/bin:/etc/profiles/per-user/root/bin:/nix/var/nix/profiles/default/bin:/run/current-system/sw/bin)

Practice: Add a User

When you need to add a new user, you can do so right from within the clan.nix file, and then update the system.

Add a New User (no sudo access)

Let's add a user called Alice. Open clan.nix, and under inventory.instances, add the following:

  inventory.instances = { # Add the following under this line
    user-alice = {
      module.name = "users";
      roles.default.machines."test-machine" = {};
      roles.default.tags.all = {};
      roles.default.settings = {
        user = "alice";
      };
    };

Save the file. Now type the following to add a password for alice (include the no-sandbox if you needed no sandbox earlier):

clan vars generate test-machine --no-sandbox

You will be prompted for a password. Or you can press Enter to automatically generate one.

If you automatically generated one, to retrieve it type:

clan vars get test-machine user-password-alice/user-password

Now update the machine by typing:

clan machines update test-machine

Once complete, you can log in as alice with the password on the target machine.

Give that user sudo access

After you trust Alice, you can grant her sudo access. To do so, update the clan.nix file by adding her to the wheel group:

    user-alice = {
      module.name = "users";
      roles.default.machines."test-machine" = {};
      roles.default.tags.all = {};
      roles.default.settings = {
        user = "alice";
        groups = [ "wheel" ];  # Add this to allow sudo
      };
    };

Again type:

clan machines update test-machine

If you were already logged in as alice before running the update, you will need to log out and back in for the change to take.

Then after logged in, try using sudo:

sudo echo "hello"

You will be prompted for the password and should see "hello" printed.

Revoke the sudo access

To revoke alice's sudo access, simply remove the line you added:

        groups = [ "wheel" ];

And once again run:

clan machines update test-machine

Log out, and log alice back in. Now try the same sudo command; you'll be prompted for password, but then shown:

alice is not in the sudoers file.