extend nixpkgs's lib instead

2025-07-11 20:34:45 -07:00
parent 3ba8c1a5a6
commit 7f7dc03a20
11 changed files with 90 additions and 82 deletions
--- a/lib.nix
+++ b/lib.nix
@@ -0,0 +1,66 @@
+{
+  inputs,
+  pkgs,
+  ...
+}:
+inputs.nixpkgs.lib.extend (
+  final: prev:
+  let
+    lib = prev;
+  in
+  {
+    ensureZfsMounts =
+      dirs:
+      pkgs.writeShellApplication {
+        name = "zfslistmounted";
+        runtimeInputs = with pkgs; [
+          zfs
+          gnugrep
+          gawk
+          coreutils
+        ];
+        text = ''
+          #!/bin/sh
+          zfs list -o mountpoint,mounted -H | awk '$2 == "yes" {print $1}' | grep -c '${lib.strings.concatStringsSep "\|" dirs}' | grep -Fq ${toString (lib.length dirs)}
+        '';
+      };
+
+    serviceMountDeps = serviceName: dirs: {
+      systemd.services."${serviceName}_mounts" = {
+        unitConfig.Wants = "zfs.target";
+        serviceConfig = {
+          Type = "oneshot";
+          RemainAfterExit = true;
+          ExecStart = lib.getExe (final.ensureZfsMounts dirs);
+        };
+      };
+
+      systemd.services.${serviceName} = {
+        wants = [ "${serviceName}_mounts.service" ];
+      };
+    };
+
+    # stolen from: https://stackoverflow.com/a/42398526
+    optimizeWithFlags =
+      pkg: flags:
+      lib.overrideDerivation pkg (
+        old:
+        let
+          newflags = lib.foldl' (acc: x: "${acc} ${x}") "" flags;
+          oldflags = if (lib.hasAttr "NIX_CFLAGS_COMPILE" old) then "${old.NIX_CFLAGS_COMPILE}" else "";
+        in
+        {
+          NIX_CFLAGS_COMPILE = "${oldflags} ${newflags}";
+          # stdenv = pkgs.clang19Stdenv;
+        }
+      );
+
+    optimizePackage =
+      pkg:
+      final.optimizeWithFlags pkg [
+        "-O3"
+        "-march=znver3"
+        "-mtune=znver3"
+      ];
+  }
+)