feat: Add initial NixOS configuration

Adds NixOS configuration to configure my base system with all sorts of things,
including - but not limited to - i3, emacs, FF57, connman and so on.

Not all of these things are fully configured yet (especially in the desktop
environment) but I'm hoping to get more of that done in the future.

configuration.nix

@@ -0,0 +1,119 @@
+# Edit this configuration file to define what should be installed on
+# your system.  Help is available in the configuration.nix(5) man page
+# and in the NixOS manual (accessible by running ‘nixos-help’).
+
+{ config, pkgs, ... }:
+
+let
+  unstable = import <nixos-unstable> { config.allowUnfree = true; };
+in {
+  imports =
+    [ # Include the results of the hardware scan.
+    ./hardware-configuration.nix
+    ./local-configuration.nix
+    ];
+
+  # Ensure encrypted devices are decrypted
+  boot.initrd.luks.devices.adho.device = "/dev/disk/by-uuid/722006b0-9654-4ea1-8703-e0cf9ac1905e";
+
+  # Use the systemd-boot EFI boot loader.
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+
+  # Use connman for network configuration
+  networking.connman.enable = true;
+  hardware.pulseaudio.enable = true;
+  programs.light.enable = true;
+
+  # Set your time zone.
+  time.timeZone = "Europe/Oslo";
+
+  # List packages installed in system profile. To search by name, run:
+  # $ nix-env -qaP | grep wget
+  environment.systemPackages = with pkgs; [
+    curl gnumake unzip openjdk gcc htop tree direnv tmux fish ripgrep
+    gnupg pass git
+  ];
+
+  # Enable the X11 windowing system.
+  services.xserver.enable = true;
+  services.xserver.layout = "us,no";
+  services.xserver.xkbOptions = "caps:super, grp:shifts_toggle";
+
+  # Configure i3 & compositor
+  services.xserver.windowManager.i3.enable = true;
+  services.compton.enable = true;
+
+  # Configure Redshift for Oslo
+  services.redshift.enable = true;
+  services.redshift.latitude = "59.911491";
+  services.redshift.longitude = "10.757933";
+
+  # Configure shell environment
+  programs.fish.enable = true;
+  programs.ssh.startAgent = true;
+  services.emacs.enable = true;
+  services.emacs.defaultEditor = true;
+
+  # Configure other random applications:
+  programs.java.enable = true;
+  nixpkgs.config.allowUnfree = true;
+
+  # Configure fonts
+  fonts = {
+    fonts = with pkgs; [
+      input-fonts
+    ];
+  };
+  
+  # Configure user account
+  users.defaultUserShell = pkgs.fish;
+  users.extraUsers.vincent = {
+    extraGroups = [ "wheel" ];
+    isNormalUser = true;
+    uid = 1000;
+    shell = pkgs.fish;
+    packages = with pkgs; [
+      jetbrains.idea-community pavucontrol spotify xclip tdesktop
+      rofi rofi-pass alacritty i3lock unstable.firefox-beta-bin
+    ];
+  };
+
+  # Configure random setting of wallpapers
+  systemd.user.services.clone-wallpapers = {
+    description = "Clone wallpaper repository";
+    enable = true;
+    before = [ "feh-wp.service" "feh-wp.timer" ]
+    serviceConfig = {
+      Type = "oneshot";
+      ExecStart = "${pkgs.fish}/bin/fish -c '${pkgs.coreutils}/bin/stat %h/wallpapers; or ${pkgs.git}/bin/git clone https://git.tazj.in/tazjin/wallpapers.git %h/wallpapers'";
+    };
+  };
+
+  systemd.user.services.feh-wp = {
+    description = "Randomly set wallpaper via feh";
+    serviceConfig = {
+      Type = "oneshot";
+      ExecStart = "${pkgs.feh}/bin/feh --recursive --randomize --bg-fill %h/wallpapers";
+    };
+  };
+
+  systemd.user.timers.feh-wp = {
+    description = "Set a random wallpaper every hour";
+    wantedBy = [ "timers.target" ];
+
+    timerConfig = {
+      OnActiveSec = "3second";
+      OnUnitActiveSec = "1hour";
+    };
+  };
+
+  security.sudo.enable = true;
+  security.sudo.extraConfig = "wheel ALL=(ALL:ALL) SETENV: ALL";
+
+  # This value determines the NixOS release with which your system is to be
+  # compatible, in order to avoid breaking some software such as database
+  # servers. You should change this only after NixOS release notes say you
+  # should.
+  system.stateVersion = "17.09"; # Did you read the comment?
+}