packet: add app to deploy

Author: vaibhavsagar

packet/deploy/app/Main.hs

@@ -0,0 +1,11 @@
+ {-# LANGUAGE OverloadedStrings #-}
+
+import Web.Scotty
+import System.Environment (getArgs)
+
+import Data.Monoid (mconcat)
+
+main = getArgs >>= \(port:_) -> scotty (read port) $ do
+    get "/:word" $ do
+        beam <- param "word"
+        html $ mconcat ["<h1>Scotty, ", beam, " me up!</h1>"]

packet/deploy/app/blank-me-up.cabal

@@ -0,0 +1,11 @@
+name:                blank-me-up
+version:             0.1.0.0
+license:             BSD3
+build-type:          Simple
+cabal-version:       >=1.10
+
+executable blank-me-up
+  main-is:             Main.hs
+  build-depends:       base >=4.9 && <5
+                     , scotty
+  default-language:    Haskell2010

packet/deploy/nix/service.nix

@@ -0,0 +1,27 @@
+{ config, lib, pkgs, ... }:
+
+let
+  blank-me-up = pkgs.haskellPackages.callCabal2nix "blank-me-up" ../app {};
+  cfg = config.services.blank-me-up;
+in {
+  options.services.blank-me-up.enable = lib.mkEnableOption "Blank Me Up";
+  options.services.blank-me-up.port = lib.mkOption {
+    default = 3000;
+    type = lib.types.int;
+  };
+
+  config = lib.mkIf cfg.enable {
+    networking.firewall.allowedTCPPorts = [ cfg.port ];
+
+    systemd.services.blank-me-up = {
+      description = "Blank Me Up";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        ExecStart = "${blank-me-up}/bin/blank-me-up ${toString cfg.port}";
+        Restart = "always";
+        KillMode = "process";
+      };
+    };
+  };
+}