reimplement disko using the nixos type system

This should make the code cleaner, more robust and errors should be
clearer. we also changed the configuration format a bit.

1 files changed, 18 insertions, 308 deletions

diff --git a/default.nix b/default.nix
index 51b70f5..9febd80 100644
--- a/default.nix
+++ b/default.nix
@@ -1,312 +1,22 @@
-{ lib ? import <nixpkgs/lib> }:
-with lib;
-with builtins;
-
+{ lib ? import <nixpkgs/lib>
+, pkgs ? import <nixpkgs> {}
+}:
 let
-
-  helper.find-device = device:
-    let
-      environment = helper.device-id device;
-    in
-    # DEVICE points already to /dev/disk, so we don't handle it via /dev/disk/by-path
-    if hasPrefix "/dev/disk" device then
-      "${environment}='${device}'"
-    else ''
-      ${environment}=$(for x in $(find /dev/disk/{by-path,by-id}/); do
-        dev=$x
-        if [ "$(readlink -f $x)" = "$(readlink -f '${device}')" ]; then
-          target=$dev
-          break
-        fi
-      done
-      if test -z ''${target+x}; then
-        echo 'unable to find path of disk: ${device}, bailing out' >&2
-        exit 1
-      else
-        echo $target
-      fi)
-    '';
-
-  helper.device-id = device: "DEVICE${builtins.substring 0 5 (builtins.hashString "sha1" device)}";
-
-  config-f = q: x: config.${x.type} q x;
-
-  config.filesystem = q: x: {
-    fileSystems.${x.mountpoint} = {
-      device = q.device;
-      fsType = x.format;
-      ${if x ? options then "options" else null} = x.options;
-    };
-  };
-
-  config.zfs_filesystem = q: x: {
-    fileSystems.${x.mountpoint} = {
-      device = q.device;
-      fsType = "zfs";
+  types = import ./types.nix { inherit pkgs; };
+  eval = cfg: lib.evalModules {
+    modules = lib.singleton {
+      # _file = toString input;
+      imports = lib.singleton { topLevel.devices = cfg; };
+      options = {
+        topLevel = lib.mkOption {
+          type = types.topLevel;
+        };
+      };
     };
   };
-
-  config.devices = q: x:
-    foldl' recursiveUpdate { } (mapAttrsToList (name: config-f { device = "/dev/${name}"; }) x.content);
-
-  config.luks = q: x: {
-    boot.initrd.luks.devices.${x.name}.device = q.device;
-  } // config-f { device = "/dev/mapper/${x.name}"; } x.content;
-
-  config.lvm_lv = q: x:
-    config-f { device = "/dev/${q.vgname}/${q.name}"; } x.content;
-
-  config.lvm_vg = q: x:
-    foldl' recursiveUpdate { } (mapAttrsToList (name: config-f { inherit name; vgname = x.name; }) x.lvs);
-
-  config.noop = q: x: { };
-
-  config.partition = q: x:
-    config-f { device = q.device + toString q.index; } x.content;
-
-  config.table = q: x:
-    foldl' recursiveUpdate { } (imap (index: config-f (q // { inherit index; })) x.partitions);
-
-
-  create-f = q: x: create.${x.type} q x;
-
-  create.btrfs = q: x: ''
-    mkfs.btrfs ${q.device}
-    ${lib.optionalString (!isNull x.subvolumes or null) ''
-      MNTPOINT=$(mktemp -d)
-      (
-        mount ${q.device} "$MNTPOINT"
-        trap 'umount $MNTPOINT; rm -rf $MNTPOINT' EXIT
-        ${concatMapStringsSep "\n" (subvolume: "btrfs subvolume create \"$MNTPOINT\"/${subvolume}") x.subvolumes}
-      )
-    ''}
-  '';
-
-  create.filesystem = q: x: ''
-    mkfs.${x.format} \
-      ${lib.optionalString (!isNull x.extraArgs or null) x.extraArgs} \
-      ${q.device}
-  '';
-
-  create.devices = q: x:
-    let
-      raid-devices = lib.filterAttrs (_: dev: dev.type == "mdadm" || dev.type == "zpool" || dev.type == "lvm_vg") x.content;
-      other-devices = lib.filterAttrs (_: dev: dev.type != "mdadm" && dev.type != "zpool" && dev.type != "lvm_vg") x.content;
-    in
-    ''
-      ${concatStrings (mapAttrsToList (name: create-f { device = "/dev/${name}"; }) other-devices)}
-      ${concatStrings (mapAttrsToList (name: create-f { device = "/dev/${name}"; name = name; }) raid-devices)}
-    '';
-
-  create.mdraid = q: x: ''
-    RAIDDEVICES_N_${x.name}=$((''${RAIDDEVICES_N_${x.name}:-0}+1))
-    RAIDDEVICES_${x.name}="''${RAIDDEVICES_${x.name}:-}${q.device} "
-  '';
-
-  create.mdadm = q: x: ''
-    echo 'y' | mdadm --create /dev/md/${q.name} --level=${toString x.level or 1} --raid-devices=''${RAIDDEVICES_N_${q.name}} ''${RAIDDEVICES_${q.name}}
-    udevadm trigger --subsystem-match=block; udevadm settle
-    ${create-f { device = "/dev/md/${q.name}"; } x.content}
-  '';
-
-  create.luks = q: x: ''
-    cryptsetup -q luksFormat ${q.device} ${if builtins.hasAttr "keyfile" x then x.keyfile else ""} ${toString (x.extraArgs or [])}
-    cryptsetup luksOpen ${q.device} ${x.name} ${if builtins.hasAttr "keyfile" x then "--key-file " + x.keyfile else ""}
-    ${create-f { device = "/dev/mapper/${x.name}"; } x.content}
-  '';
-
-  create.lvm_pv = q: x: ''
-    pvcreate ${q.device}
-    LVMDEVICES_${x.vg}="''${LVMDEVICES_${x.vg}:-}${q.device} "
-  '';
-
-  create.lvm_lv = q: x: ''
-    lvcreate \
-      ${if hasInfix "%" x.size then "-l" else "-L"} ${x.size} \
-      -n ${q.name} \
-      ${lib.optionalString (!isNull x.lvm_type or null) "--type=${x.lvm_type}"} \
-      ${lib.optionalString (!isNull x.extraArgs or null) x.extraArgs} \
-      ${q.vgname}
-    ${create-f { device = "/dev/${q.vgname}/${q.name}"; } x.content}
-  '';
-
-  create.lvm_vg = q: x: ''
-    vgcreate ${q.name} $LVMDEVICES_${q.name}
-    ${concatStrings (mapAttrsToList (name: create-f { inherit name; vgname = q.name; }) x.lvs)}
-  '';
-
-  create.noop = q: x: "";
-
-  create.partition = q: x:
-    let
-      env = helper.device-id q.device;
-    in
-    ''
-      parted -s "''${${env}}" mkpart ${x.part-type} ${x.fs-type or ""} ${x.start} ${x.end}
-      # ensure /dev/disk/by-path/..-partN exists before continuing
-      udevadm trigger --subsystem-match=block; udevadm settle
-      ${optionalString (x.bootable or false) ''
-        parted -s "''${${env}}" set ${toString q.index} boot on
-      ''}
-      ${concatMapStringsSep "" (flag: ''
-        parted -s "''${${env}}" set ${toString q.index} ${flag} on
-      '') (x.flags or [])}
-      ${create-f { device = "\"\${${env}}\"-part" + toString q.index; } x.content}
-    '';
-
-  create.table = q: x: ''
-    ${helper.find-device q.device}
-    parted -s "''${${helper.device-id q.device}}" mklabel ${x.format}
-    ${concatStrings (imap (index: create-f (q // { inherit index; })) x.partitions)}
-  '';
-
-  create.zfs = q: x: ''
-    ZFSDEVICES_${x.pool}="''${ZFSDEVICES_${x.pool}:-}${q.device} "
-  '';
-
-  create.zfs_filesystem = q: x: ''
-    zfs create ${q.pool}/${x.name} \
-      ${lib.optionalString (isAttrs x.options or null) (concatStringsSep " " (mapAttrsToList (n: v: "-o ${n}=${v}") x.options))}
-  '';
-
-  create.zfs_volume = q: x: ''
-    zfs create ${q.pool}/${x.name} \
-      -V ${x.size} \
-      ${lib.optionalString (isAttrs x.options or null) (concatStringsSep " " (mapAttrsToList (n: v: "-o ${n}=${v}") x.options))}
-    udevadm trigger --subsystem-match=block; udevadm settle
-    ${create-f { device = "/dev/zvol/${q.pool}/${x.name}"; } x.content}
-  '';
-
-  create.zpool = q: x: ''
-    zpool create ${q.name} \
-      ${lib.optionalString (!isNull (x.mode or null) && x.mode != "stripe") x.mode} \
-      ${lib.optionalString (isAttrs x.options or null) (concatStringsSep " " (mapAttrsToList (n: v: "-o ${n}=${v}") x.options))} \
-      ${lib.optionalString (isAttrs x.rootFsOptions or null) (concatStringsSep " " (mapAttrsToList (n: v: "-O ${n}=${v}") x.rootFsOptions))} \
-      ''${ZFSDEVICES_${q.name}}
-    ${concatMapStrings (create-f (q // { pool = q.name; })) x.datasets}
-  '';
-
-
-  mount-f = q: x: mount.${x.type} q x;
-
-  mount.filesystem = q: x: {
-    fs.${x.mountpoint} = ''
-      if ! findmnt ${q.device} "/mnt${x.mountpoint}" > /dev/null 2>&1; then
-        mount ${q.device} "/mnt${x.mountpoint}" \
-        -o X-mount.mkdir \
-        ${lib.optionalString (isList x.mountOptions or null) (concatStringsSep " " x.mountOptions)}
-      fi
-    '';
-  };
-
-  mount.zfs_filesystem = q: x:
-    optionalAttrs ((x.options.mountpoint or "") != "none")
-      (mount.filesystem (q // { device = q.dataset; }) (x // { mountOptions = [
-        (lib.optionalString ((x.options.mountpoint or "") != "legacy") "-o zfsutil")
-        "-t zfs"
-      ]; }));
-
-  mount.btrfs = mount.filesystem;
-
-  mount.devices = q: x:
-    let
-      z = foldl' recursiveUpdate { } (mapAttrsToList (name: mount-f { device = "/dev/${name}"; inherit name; }) x.content);
-      # attrValues returns values sorted by name.  This is important, because it
-      # ensures that "/" is processed before "/foo" etc.
-    in
-    ''
-      ${optionalString (hasAttr "table" z) (concatStringsSep "\n" (attrValues z.table))}
-      ${optionalString (hasAttr "luks" z) (concatStringsSep "\n" (attrValues z.luks))}
-      ${optionalString (hasAttr "lvm" z) (concatStringsSep "\n" (attrValues z.lvm))}
-      ${optionalString (hasAttr "zpool" z) (concatStringsSep "\n" (attrValues z.zpool))}
-      ${optionalString (hasAttr "zfs" z) (concatStringsSep "\n" (attrValues z.zfs))}
-      ${optionalString (hasAttr "fs" z) (concatStringsSep "\n" (attrValues z.fs))}
-    '';
-
-  mount.luks = q: x: (
-    recursiveUpdate
-      (mount-f { device = "/dev/mapper/${x.name}"; } x.content)
-      {
-        luks.${q.device} = ''
-          cryptsetup status ${x.name} >/dev/null 2>/dev/null || cryptsetup luksOpen ${q.device} ${x.name} ${if builtins.hasAttr "keyfile" x then "--key-file " + x.keyfile else ""}
-        '';
-      }
-  );
-
-  mount.lvm_lv = q: x:
-    mount-f { device = "/dev/${q.vgname}/${q.name}"; } x.content;
-
-  mount.lvm_vg = q: x: (
-    recursiveUpdate
-      (foldl' recursiveUpdate { } (mapAttrsToList (name: mount-f { inherit name; vgname = q.name; }) x.lvs))
-      {
-        lvm.${q.device} = ''
-          vgchange -a y
-        '';
-      }
-  );
-
-  mount.lvm_pv = mount.noop;
-
-  mount.noop = q: x: { };
-
-  mount.mdadm = q: x:
-    mount-f { device = "/dev/md/${q.name}"; } x.content;
-  mount.mdraid = mount.noop;
-
-  mount.partition = q: x:
-    mount-f { device = "\"\${${q.device}}\"-part" + toString q.index; } x.content;
-
-  mount.table = q: x: (
-    recursiveUpdate
-      (foldl' recursiveUpdate { } (imap (index: mount-f (q // { inherit index; device = helper.device-id q.device; })) x.partitions))
-      { table.${q.device} = helper.find-device q.device; }
-  );
-
-  mount.zfs = mount.noop;
-
-  mount.zpool = q: x:
-    let
-      datasets = [{
-        inherit (q) name;
-        type = "zfs_filesystem";
-        dataset = q.name;
-        mountpoint = x.mountpoint or "/${q.name}";
-        options = q.rootFsOptions or { };
-      }] ++ x.datasets;
-    in
-    recursiveUpdate
-      (foldl' recursiveUpdate { }
-        (
-          (map
-            (x: mount-f
-              ({
-                dataset = x.dataset or "${q.name}/${x.name}";
-                mountpoint = x.mountpoint or "/${q.name}/${x.name}";
-              } // q)
-              x)
-            datasets)
-        )
-      )
-      {
-        zpool.${q.device} = ''
-          zpool list '${q.name}' >/dev/null 2>/dev/null || zpool import '${q.name}'
-        '';
-      };
-
-  mount.zfs_volume = q: x:
-    mount-f { device = "/dev/zvol/${q.dataset}"; } x.content;
-
-in
-{
-  config = config-f { };
-  create = cfg: ''
-    set -efux
-    ${create-f {} cfg}
-  '';
-  mount = cfg: ''
-    set -efux
-    ${mount-f {} cfg}
-  '';
-
+in {
+  types = types;
+  create = cfg: (eval cfg).config.topLevel.create;
+  mount = cfg: (eval cfg).config.topLevel.mount;
+  config = cfg: (eval cfg).config.topLevel.config;
 }