Host Setup Instructions

These are the steps I use when bringing up a new host with this repo.

1. Set up GitHub SSH access

If you already have a working SSH key that is added to GitHub, skip this section.

Check whether a key already exists:

ls -l ~/.ssh/id_ed25519 ~/.ssh/id_ed25519.pub

If you want a fresh key, move the old one aside first instead of deleting it:

mv ~/.ssh/id_ed25519 ~/.ssh/id_ed25519.old.$(date +%s) 2>/dev/null || true
mv ~/.ssh/id_ed25519.pub ~/.ssh/id_ed25519.pub.old.$(date +%s) 2>/dev/null || true

Generate a new key:

ssh-keygen -t ed25519 -C "you@example.com"

Start the agent and add the key:

eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519
chmod 600 ~/.ssh/id_ed25519

Print the public key and add it to GitHub:

cat ~/.ssh/id_ed25519.pub

Add it here:

https://github.com/settings/ssh/new

2. Install bootstrap tools

nix-shell -p git micro

3. Clone the repo

git clone git@github.com:TheTechRun/nixos-ttr.git ~/nixos-config
cd ~/nixos-config
git config --global user.email "you@example.com"
git config --global user.name "user"
git config --global init.defaultBranch master

4. Rename users if needed

If you do not want to use the default usernames from this repo, run the rename script now before the first flake rebuild.

Example:

~/nixos-config/scripts/user-rename.sh ttr muffin

This updates the repo's user-related text and curated modules/users/ paths so your host imports and user modules stay consistent.

5. Back up host config and copy hardware config

Pick the host first:

export HOST=desktop

Valid values here are:

• desktop
• laptop
• server
• minimal

Then back up the current /etc/nixos files and copy the generated hardware config into this repo:

mkdir -p ~/nixos-config/hosts/$HOST/backups
sudo cp /etc/nixos/configuration.nix ~/nixos-config/hosts/$HOST/backups/configuration.nix.backup
sudo cp /etc/nixos/hardware-configuration.nix ~/nixos-config/hosts/$HOST/backups/hardware-configuration.nix.backup
sudo cp /etc/nixos/hardware-configuration.nix ~/nixos-config/hosts/$HOST/hardware-configuration.nix

6. Bootstrap old hosts if needed

This section exists because the first flake rebuild can fail when the machine is still on an older NixOS release. If the installed host is behind the release expected by this repo, update the host release first and then do the flake rebuild.

Check the current host version:

nixos-version

Or:

cat /etc/os-release

You can use the helper script:

~/nixos-config/scripts/channel-update.sh

Or do it manually:

Remove the existing channel:

sudo nix-channel --remove nixos

Add the correct channel:

sudo nix-channel --add https://nixos.org/channels/nixos-<target-version-here> nixos

Check it:

sudo nix-channel --list

Update it:

sudo nix-channel --update

Rebuild once from the current /etc/nixos config:

cd /etc/nixos
sudo nixos-rebuild switch

Only do the previous steps in the above section when the host is too old for the first flake rebuild to work cleanly.

7. Prepare the repo for the first flake rebuild

Symlink the flake into /etc/nixos:

sudo ln -sf ~/nixos-config/flake.nix /etc/nixos/flake.nix

8. First flake rebuild

Use the host selected earlier (be sure to be in the same shell that you did the $HOST export, or just do it again):

sudo nixos-rebuild switch --extra-experimental-features 'nix-command flakes' --flake ~/nixos-config#$HOST

Some Examples:

sudo nixos-rebuild switch --extra-experimental-features 'nix-command flakes' --flake ~/nixos-config#desktop
sudo nixos-rebuild switch --extra-experimental-features 'nix-command flakes' --flake ~/nixos-config#laptop
sudo nixos-rebuild switch --extra-experimental-features 'nix-command flakes' --flake ~/nixos-config#server

9. Future rebuilds

After the first successful flake rebuild, the normal command is:

sudo nixos-rebuild switch --flake ~/nixos-config#$HOST

Or use this script with auto HOST detection and git functionality:

~/nixos-config/scripts/flake-scripts/rebuild-flake.sh

Note

This setup currently builds a window-manager environment around Scroll, which is a Sway fork.

If you want a different window manager or a full desktop environment instead, change the relevant imports in your hosts/<host>/configuration.nix from:

~/nixos-config/modules/desktop-environment/