nixos

install

Preconditions:

• on the target machine set networking.hostName in configuration.nix to correspond w/ a host name from the flake
• git needs to be available, install or use nix-shell -p git
• you'll probably need to provide --extra-experimental-features nix-command --extra-experimental-features flakes args

TODO: install script internally always uses the flake from the master branch -> make configurable

Execute

nix run github:m00k/nixos?dir=shells/install
# file:///home/m00k/workspace/nixos?dir=shells/install&ref=refs/heads/f/installer&rev=d958411a535571130f1ca413dd9afdfb790640ce

to run the install script.

commands

flakes

nix flakes show # list flake outputs
nixos-rebuild dry-activate --flake ./#$HOSTNAME
nixos-rebuild dry-build --flake ./#$HOSTNAME
nixos-rebuild build-vm --flake ./#$HOSTNAME
./result/bin/run-$USER-vm # run vm (replace $USER)

https://nixos-and-flakes.thiscute.world/nixos-with-flakes/update-the-system

# Update flake.lock
nix flake update
# Or replace only the specific input, such as home-manager:
nix flake lock --update-input home-manager
# Apply the updates
sudo nixos-rebuild switch --flake ./#$HOSTNAME
# Or activate only after reboot
sudo nixos-rebuild boot --flake ./#$HOSTNAME #

remove old generations

nix-env --list-generations --profile /nix/var/nix/profiles/system
nix-env --delete-generations +10 --profile /nix/var/nix/profiles/system # keep last 10 (plus newer than current)
nix-env --delete-generations 30d --profile /nix/var/nix/profiles/system # remove older than 30 days

# use the previous generation
nix-env --rollback --profile /nix/var/nix/profiles/system

# use specific version
nix-env --switch-generation 53 --profile /nix/var/nix/profiles/system # switch to generation no. 53
nix-env --delete-generations 54 --profile /nix/var/nix/profiles/system # delete generation no. 54

# remove old generations from boot menu
nixos-rebuild boot

bootloader

# list entries
ll /boot/loader/entries

# UEFI or Legacy boot?
[ -d /sys/firmware/efi/efivars ] && echo "UEFI" || echo "Legacy"

troubleshooting

qemu vm

Impossible to log in to result of nixos-rebuild build-vm

delete the $hostname.qcow2 file if you have started the virtual machine at least once without the right users, otherwise the changes will not get picked up

resources

• https://ghedam.at/24353/tutorial-getting-started-with-home-manager-for-nix
• https://nixos-and-flakes.thiscute.world/nixos-with-flakes/nixos-with-flakes-enabled#switch-to-flake-nix
• https://github.com/NixOS/nixos-hardware/blob/master/README.md#using-nix-flakes-support