Add xdg settings, cache, cleanup script

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/configs/zsh/default.nix

@@ -4,5 +4,8 @@
     histFile = "/var/lib/zsh/history";
   };
 
-  environment.persistence."/persist".directories = [ "/var/lib/zsh" ];
+  environment = {
+    persistence."/persist".directories = [ "/var/lib/zsh" ];
+    pathsToLink = [ "/share/zsh" ];
+  };
 }

hosts/common/default.nix

@@ -12,6 +12,7 @@
     ./configs/nix-ld
     ./configs/git
     ./configs/gpg-agent
+    ./scripts/cleanup
   ];
 
   boot = {
@@ -63,8 +64,13 @@
   };
 
   nix = {
-    settings.experimental-features = [ "nix-command" "flakes" ];
+    settings = {
+      use-xdg-base-directories = true;
+      experimental-features = [ "nix-command" "flakes" ];
+    };
+
     gc.automatic = true;
+    optimise.automatic = true;
   };
 
   nixpkgs.config.allowUnfree = true;

hosts/common/scripts/cleanup/cleanup.sh

@@ -0,0 +1,34 @@
+set -e
+
+if [ "$(id -u)" -ne 0 ]; then
+  echo "This script must be run as root or with sudo privileges."
+  exit 1
+fi
+
+delete_subvolume_recursively() {
+  IFS=$'\n'
+  for i in $(btrfs subvolume list -o "$1" | cut -f 9- -d ' '); do
+    delete_subvolume_recursively "/mnt/btrfs/$i"
+  done
+  btrfs subvolume delete "$1"
+}
+
+if [[ -e /mnt/btrfs && $(mountpoint -q /mnt/btrfs) ]]; then
+  echo "/mnt/btrfs is already mounted. Exiting."
+  exit 1
+fi
+
+mkdir -p /mnt/btrfs
+mount /dev/mapper/luks /mnt/btrfs
+
+if [[ -e /mnt/btrfs/root.bak ]]; then
+  for i in /mnt/btrfs/root.bak/*; do
+    delete_subvolume_recursively "$i"
+  done
+fi
+
+umount /mnt/btrfs
+rmdir /mnt/btrfs
+
+nix-collect-garbage -d
+nix-store --gc -v

hosts/common/scripts/cleanup/default.nix

@@ -0,0 +1,5 @@
+{ pkgs, ... }:
+
+{
+  environment.systemPackages = [ (pkgs.writeShellScriptBin "nix-cleanup" (builtins.readFile ./cleanup.sh)) ];
+}