Modularize code

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

hosts/common/configs/sops/default.nix

@@ -0,0 +1,16 @@
+{ inputs, pkgs, ... }:
+
+{
+  imports = [ inputs.sops-nix.nixosModules.sops ];
+
+  environment = {
+    persistence."/persist".files = [ "/etc/ssh/ssh_host_ed25519_key" ];
+    systemPackages = with pkgs; [ sops ];
+  };
+
+  sops.age = {
+    generateKey = true;
+    sshKeyPaths = [ "/persist/etc/ssh/ssh_host_ed25519_key" ];
+    keyFile = "/var/lib/sops-nix/key.txt";
+  };
+}