From a9e9d37fc8b7df73d68f9ed78f25da15a40a1c83 Mon Sep 17 00:00:00 2001
From: Kirill Elagin <kirelagin@gmail.com>
Date: Fri, 17 Apr 2020 13:55:48 +0300
Subject: [PATCH] systemd: Add prefix to unit script derivations

Add a distinctive `unit-script` prefix to systemd unit scripts to make
them easier to find in the store directory. Do not add this prefix to
actual script file name as it clutters logs.
---
 nixos/modules/system/boot/systemd.nix | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/nixos/modules/system/boot/systemd.nix b/nixos/modules/system/boot/systemd.nix
index caa3435cfcd..516f8ed7541 100644
--- a/nixos/modules/system/boot/systemd.nix
+++ b/nixos/modules/system/boot/systemd.nix
@@ -203,10 +203,20 @@ let
   makeJobScript = name: text:
     let
       scriptName = replaceChars [ "\\" "@" ] [ "-" "_" ] (shellEscape name);
-      out = pkgs.writeShellScriptBin scriptName ''
-        set -e
-        ${text}
-      '';
+      out = pkgs.writeTextFile {
+        # The derivation name is different from the script file name
+        # to keep the script file name short to avoid cluttering logs.
+        name = "unit-script-${scriptName}";
+        executable = true;
+        destination = "/bin/${scriptName}";
+        text = ''
+          #!${pkgs.runtimeShell} -e
+          ${text}
+        '';
+        checkPhase = ''
+          ${pkgs.stdenv.shell} -n "$out/bin/${scriptName}"
+        '';
+      };
     in "${out}/bin/${scriptName}";
 
   unitConfig = { config, options, ... }: {