types: init swap

example/swap.nix

@@ -0,0 +1,52 @@
+{ disks ? [ "/dev/vdb" ], ... }: {
+  disk = {
+    vdb = {
+      device = builtins.elemAt disks 0;
+      type = "disk";
+      content = {
+        type = "table";
+        format = "gpt";
+        partitions = [
+          {
+            type = "partition";
+            name = "ESP";
+            start = "1MiB";
+            end = "100MiB";
+            bootable = true;
+            content = {
+              type = "filesystem";
+              format = "vfat";
+              mountpoint = "/boot";
+            };
+          }
+          {
+            name = "root";
+            type = "partition";
+            start = "100MiB";
+            end = "-1G";
+            part-type = "primary";
+            bootable = true;
+            content = {
+              type = "filesystem";
+              format = "ext4";
+              mountpoint = "/";
+            };
+          }
+          {
+            name = "root";
+            type = "partition";
+            start = "-1G";
+            end = "100%";
+            part-type = "primary";
+            bootable = true;
+            content = {
+              type = "swap";
+              randomEncryption = true;
+            };
+          }
+        ];
+      };
+    };
+  };
+}
+

module.nix

@@ -42,5 +42,6 @@ in {
     # Remember to add config keys here if they are added to types
     fileSystems = lib.mkIf cfg.enableConfig (lib.mkMerge (lib.catAttrs "fileSystems" (types.diskoLib.config cfg.devices)));
     boot = lib.mkIf cfg.enableConfig (lib.mkMerge (lib.catAttrs "boot" (types.diskoLib.config cfg.devices)));
+    swapDevices = lib.mkIf cfg.enableConfig (lib.mkMerge (lib.catAttrs "swapDevices" (types.diskoLib.config cfg.devices)));
   };
 }

tests/swap.nix

@@ -0,0 +1,19 @@
+{ pkgs ? (import <nixpkgs> { })
+, makeDiskoTest ? (pkgs.callPackage ./lib.nix { }).makeDiskoTest
+}:
+makeDiskoTest {
+  disko-config = ../example/swap.nix;
+  extraTestScript = ''
+    machine.succeed("mountpoint /");
+    machine.succeed("swapon --show >&2");
+    machine.succeed("""
+      lsblk --json |
+        ${pkgs.jq}/bin/jq -e '.blockdevices[] |
+          select(.name == "vda") |
+          .children[] |
+          select(.name == "vda3") |
+          .children[0].mountpoints[0] == "[SWAP]"
+        '
+    """);
+  '';
+}

types.nix

@@ -18,13 +18,13 @@ rec {
 
     # option for valid contents of partitions (basically like devices, but without tables)
     partitionType = mkOption {
-      type = types.nullOr (diskoLib.subType { inherit btrfs filesystem zfs mdraid luks lvm_pv; });
+      type = types.nullOr (diskoLib.subType { inherit btrfs filesystem zfs mdraid luks lvm_pv swap; });
       default = null;
     };
 
     # option for valid contents of devices
     deviceType = mkOption {
-      type = types.nullOr (diskoLib.subType { inherit table btrfs filesystem zfs mdraid luks lvm_pv; });
+      type = types.nullOr (diskoLib.subType { inherit table btrfs filesystem zfs mdraid luks lvm_pv swap; });
       default = null;
     };
 
@@ -547,6 +547,62 @@ rec {
     };
   });
 
+  swap = types.submodule ({ config, ... }: {
+    options = {
+      type = mkOption {
+        type = types.enum [ "swap" ];
+        internal = true;
+      };
+      randomEncryption = mkOption {
+        type = types.bool;
+        default = false;
+      };
+      _meta = mkOption {
+        internal = true;
+        readOnly = true;
+        type = types.functionTo diskoLib.jsonType;
+        default = dev: {
+        };
+      };
+      _create = mkOption {
+        internal = true;
+        readOnly = true;
+        type = types.functionTo types.str;
+        default = dev: ''
+          mkswap ${dev}
+        '';
+      };
+      _mount = mkOption {
+        internal = true;
+        readOnly = true;
+        type = types.functionTo diskoLib.jsonType;
+        default = dev: {
+          fs.${dev} = ''
+            if ! $(swapon --show | grep -q '^${dev} '); then
+              swapon ${dev}
+            fi
+          '';
+        };
+      };
+      _config = mkOption {
+        internal = true;
+        readOnly = true;
+        default = dev: [{
+          swapDevices = [{
+            device = dev;
+            randomEncryption = config.randomEncryption;
+          }];
+        }];
+      };
+      _pkgs = mkOption {
+        internal = true;
+        readOnly = true;
+        type = types.functionTo (types.listOf types.package);
+        default = pkgs: [ pkgs.util-linux ];
+      };
+    };
+  });
+
   lvm_pv = types.submodule ({ config, ... }: {
     options = {
       type = mkOption {
@@ -1158,7 +1214,7 @@ rec {
         type = types.enum [ "disk" ];
       };
       device = mkOption {
-        type = optionTypes.absolute-pathname; # TODO check if subpath of /dev ?
+        type = optionTypes.absolute-pathname; # TODO check if subpath of /dev ? - No! eg: /.swapfile
       };
       content = diskoLib.deviceType;
       _meta = mkOption {