parameterize data disk mount point

modules/custom/data-disk.nix

@@ -3,17 +3,35 @@ let cfg = config.custom.dataDisk;
 in {
   options = {
     custom = {
-      dataDisk.enable = lib.mkOption {
-        default = false;
-        type = lib.types.bool;
-        description = ''
-          Whether to automatically mount /dev/sda1 on /mnt/data
-        '';
+      dataDisk = {
+        enable = lib.mkOption {
+          default = false;
+          type = lib.types.bool;
+          description = ''
+            Whether to automatically mount a disk to be used as a data disk.
+          '';
+        };
+
+        mountPoint = lib.mkOption {
+          default = "/mnt/data";
+          type = lib.types.str;
+          description = ''
+            Mount point of the data disk (if enabled).
+          '';
+        };
+
+        devicePath = lib.mkOption {
+          default = "/dev/sda1";
+          type = lib.types.str;
+          description = ''
+            Path of the device to be used as a data disk.
+          '';
+        };
       };
     };
   };
 
   config = lib.mkIf cfg.enable {
-    fileSystems."/mnt/data" = { device = "/dev/sda1"; };
+    fileSystems.${cfg.mountPoint} = { device = cfg.devicePath; };
   };
 }

modules/custom/k3s.nix

@@ -17,17 +17,15 @@ in {
     environment.systemPackages = [ pkgs.k3s ];
     services.k3s.enable = true;
     services.k3s.role = "server";
-    # TODO: parameterize data disk mount point.
-    services.k3s.extraFlags = "--tls-san ${config.networking.fqdn} --data-dir /mnt/data/k3s";
+    services.k3s.extraFlags = "--tls-san ${config.networking.fqdn} --data-dir ${config.custom.dataDisk.mountPoint}/k3s";
 
-    # TODO: parameterize data disk mount point.
     # TODO: use kubenix for this.
     system.activationScripts.k3s-bootstrap.text =
       let
         k3sBootstrapFile = pkgs.writeText "k3s-bootstrap" (builtins.readFile ./k3s-bootstrap.yaml);
       in
       ''
-        ln -sf ${k3sBootstrapFile} /mnt/data/k3s/server/manifests/k3s-bootstrap.yaml
+        ln -sf ${k3sBootstrapFile} ${config.custom.dataDisk.mountPoint}/k3s/server/manifests/k3s-bootstrap.yaml
       '';
   };
 }

modules/custom/terraform-database.nix

@@ -20,7 +20,7 @@ in {
       package = pkgs.postgresql_15;
       enableTCPIP = true;
       dataDir = lib.mkIf config.custom.dataDisk.enable
-        "/mnt/data/postgresql/${config.services.postgresql.package.psqlSchema}";
+        "${config.custom.dataDisk.mountPoint}/postgresql/${config.services.postgresql.package.psqlSchema}";
       authentication = ''
         hostssl terraformstates terraform all cert
       '';