Common system config for Chris' various jawns

A common, version-controlled set of system configurations for various NixOS systems I own.

Usage

• Edit the https://github.com/mcdonc/.nixconfig/blob/master/flake.nix file, adding the new system to nixosConfigurations, referencing a file we intend to create in the repo's hosts dir (e.g. hosts/mynewsystem.nix) in a subsequent step:

  mynewsystem = nixpkgs.lib.nixosSystem {
    inherit system specialArgs;
    modules = shared-modules ++ [ ./hosts/mynewsystem.nix ];
  };

• Add the hosts/mynewsystem.nix file, copying another host file to start with. Remember to change the hostId and hostName. Use this for the hostId:

  openssl rand -hex 4

• Add the following to the hosts/mynewsystem.nix (bw compat issue):

  fileSystems."/nix" =
    { device = "NIXROOT/nix";
      fsType = "zfs";
    };

• Check in and push.

• Check out this repository into ~/.nixconfig within the NixOS installer on the new system:

  cd
  git clone https://github.com/mcdonc/.nixconfig.git

• Run the prepsystem.sh script. The first argument should be the device name to prepare (e.g. /dev/nvme1n1 or /dev/sda). The second --optional -- argument allows the partition names created to have a suffix (in case you're installing a second Nix on a system that already has one device formatted with the defaults).:

  sudo ~/.nixconfig/prepsystem.sh /dev/nvme1n1

• This will mount the prepared system on /mnt.

• Move the system-generated /mnt/etc/nixos aside:

  sudo mv /mnt/etc/nixos /mnt/etc/nixos_aside

• Copy the ~/.nixconfig directory on top of /mnt/etc/nixos (not into it, it should become /mnt/etc/nixos):

  cd
  sudo cp -r .nixconfig /mnt/etc/nixos

• Install the system:

  sudo nixos-install  --flake /mnt/etc/nixos#mynewsystem

• Copy the generated /mnt/etc/nixos_aside/hardware-configuration.nix to a safe place to capture what the scanner found that is not yet reflected in the checked in config:

  $ passwd   # (change nixos user passwd)
  $ ifconfig # (see ip address)
  
  ssh nixos@<ip address> and cut n paste hardware config, add as comment to
    hosts/mynewsystem.nix

• Reboot.

Post-Reboot

• Change your user's password.
• Put your private SSH key into ~/.ssh (e.g. id_rsa). At the next relogin you will be prompted by ksshaskpass for its passphrase. You will also need to change the kdewallet password to the new password you gave your user for it to save successfully.

• Change ownership of /etc/nixos (this used to be /mnt/etc/nixos before the reboot) to your user, so you can commit and pull.:

  sudo chown -R chrism:users /etc/nixos

• Convert the https checkout of /etc/nixos to an ssh checkout by changing url = https://github.com/mcdonc/.nixconfig.git to url = git@github.com:mcdonc/.nixconfig.git in the [remote "origin"] section of /etc/nixos/.git/config.

• Set up swap space if necessary (change 8GB to whatever):

  zfs create -V 8G -b 16384 -o compression=zle \
     -o logbias=throughput -o sync=always \
     -o primarycache=metadata -o secondarycache=none \
     -o com.sun:auto-snapshot=false NIXROOT/swap
  
  mkswap -f /dev/zvol/NXROOT/swap
  
  swapon -av

  Add the swap space to swapDevices in the host's Nix config:

  swapDevices = [{ device = "/dev/zvol/NIXROOT/swap"; }];