nixos: add ihaskell service

1 files changed, 77 insertions, 0 deletions

diff --git a/nixos/modules/services/misc/ihaskell.nix b/nixos/modules/services/misc/ihaskell.nix
new file mode 100644
index 00000000000..b857045bb7d
--- /dev/null
+++ b/nixos/modules/services/misc/ihaskell.nix
@@ -0,0 +1,77 @@
+{ pkgs, lib, config, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.ihaskell;
+  ihaskell = pkgs.ihaskell.override {
+    inherit (cfg.haskellPackages) ihaskell ghcWithPackages;
+    packages = self: cfg.extraPackages self;
+  };
+
+in
+
+{
+  options = {
+    services.ihaskell = {
+      enable = mkOption {
+        default = false;
+        example = true;
+        description = "Autostart an IHaskell notebook service.";
+      };
+
+      haskellPackages = mkOption {
+        default = pkgs.haskellngPackages;
+        defaultText = "pkgs.haskellngPackages";
+        example = literalExample "pkgs.haskell-ng.packages.ghc784";
+        description = ''
+          haskellPackages used to build IHaskell and other packages.
+          This can be used to change the GHC version used to build
+          IHaskell and the packages listed in
+          <varname>extraPackages</varname>.
+        '';
+      };
+
+      extraPackages = mkOption {
+        default = self: [];
+        example = literalExample ''
+          haskellPackages: [
+            haskellPackages.wreq
+            haskellPackages.lens
+          ]
+        '';
+        description = ''
+          Extra packages available to ghc when running ihaskell. The
+          value must be a function which receives the attrset defined
+          in <varname>haskellPackages</varname> as the sole argument.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+
+    users.extraUsers.ihaskell = {
+      group = config.users.extraGroups.ihaskell.name;
+      description = "IHaskell user";
+      home = "/var/lib/ihaskell";
+      createHome = true;
+      uid = config.ids.uids.ihaskell;
+    };
+
+    users.extraGroups.ihaskell.gid = config.ids.gids.ihaskell;
+
+    systemd.services.ihaskell = {
+      description = "IHaskell notebook instance";
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target" ];
+      serviceConfig = {
+        User = config.users.extraUsers.ihaskell.name;
+        Group = config.users.extraUsers.ihaskell.name;
+        Restart = "always";
+        ExecStart = "${ihaskell}/bin/IHaskell notebook";
+      };
+    };
+  };
+}