Do some clean up of the Nix infrastructure

.envrc

@@ -1,27 +1,16 @@
 # shellcheck disable=SC2148 # .envrc files need no shell directive
 shopt -s dotglob globstar
 
-# NOTE: This file is based on https://github.com/channable/repository-template/blob/master/.envrc
-# When making edits that apply to other repositories, please update the file there.
-
-# Add possibility to run a custom envrc that completely overrides the behavior of this envrc.
-CUSTOM_ENVRC=.customenvrc
-if [ -f "$CUSTOM_ENVRC" ]; then
-  echo "Using .customenvrc file"
-  source_env $CUSTOM_ENVRC
-else
-  # Decrease logging output
-  # shellcheck disable=SC2034 # unused variable is still read by direnv.
-  DIRENV_LOG_FORMAT=
-  # Install nix-direnv, which has an improved implementation of `use nix` that
-  # caches the Nix environment. Note that this URL is cached locally, so it
-  # doesn't fetch the script every time.
-  if ! has nix_direnv_version || ! nix_direnv_version 3.0.4; then
+# Decrease logging output
+# shellcheck disable=SC2034 # unused variable is still read by direnv.
+DIRENV_LOG_FORMAT=
+# Install nix-direnv, which has an improved implementation of `use nix` that
+# caches the Nix environment. Note that this URL is cached locally, so it
+# doesn't fetch the script every time.
+if ! has nix_direnv_version || ! nix_direnv_version 3.0.4; then
     source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/3.0.4/direnvrc" "sha256-DzlYZ33mWF/Gs8DDeyjr8mnVmQGx7ASYqA5WlxwvBG4="
-  fi
-
-  watch_file  nix/sources.json nix/sources.nix nix/overlay.nix nix/python-overlay.nix opsqueue/opsqueue.nix /libs/opsqueue_python/opsqueue_python.nix
+fi
 
+watch_file ./nix/ ./**/*.nix
 
-  use nix default.nix --argstr environment shell
-fi
+use nix default.nix --argstr environment shell

.pre-commit-config.yaml

@@ -1,4 +1,3 @@
-# Pre-commit config as used by ./build.py.
 repos:
   # Use local to make sure the dependencies are taken from pre-commit's own environment and
   # therefore from our nix derivation.

default.nix

@@ -22,29 +22,40 @@ let
     ]
   );
 
+  # We choose a minimal Rust channel to keep the Nix closure size smaller
+  rust = pkgs.rust-bin.stable.latest.minimal.override {
+    extensions = [
+      "clippy"
+      "rustfmt"
+    ];
+  };
+
   defaultEnv = pkgs.buildEnv {
     name = "opsqueue-env-default";
-    paths = with pkgs; [
+    paths = [
       # Command runner
-      just
+      pkgs.just
 
       # For linting and formatting
-      pre-commit
-      pre-commit-env
+      pkgs.biome
+      pkgs.nixfmt-rfc-style
+      pkgs.pre-commit
+      pkgs.python3Packages.pre-commit-hooks
+      pkgs.ruff
 
       # For compiling the Rust parts
-      rust-with-lsp
-      sqlx-cli
+      rust
+      pkgs.sqlx-cli
 
       # Manage nix pins
-      niv
-      nvd
+      pkgs.niv
+      pkgs.nvd
 
       # Rust build tools
-      cargo-audit
-      cargo-edit
-      cargo-nextest
-      maturin
+      pkgs.cargo-audit
+      pkgs.cargo-edit
+      pkgs.cargo-nextest
+      pkgs.maturin
     ];
   };
   environments = {

libs/opsqueue_python/opsqueue_python.nix

@@ -1,5 +1,5 @@
 {
-  fileFilter,
+  lib,
   buildPythonPackage,
   rustPlatform,
   perl,
@@ -10,14 +10,18 @@
   opentelemetry-exporter-otlp,
   opentelemetry-sdk,
 }:
+let
+  root = ../../.;
+  util = import (root + /nix/util.nix) { inherit lib; };
+in
 buildPythonPackage rec {
   pname = "opsqueue";
   version = "0.1.0";
   pyproject = true;
 
-  src = fileFilter {
+  src = util.fileFilter {
     name = "opsqueue_python";
-    src = ../../.;
+    src = root;
 
     # We're copying slightly too much to the Nix store here,
     # but using the more granular file filter was very error-prone.

nix/overlay.nix

@@ -1,88 +1,16 @@
-# Overlay for Nixpkgs which holds rust-jobs related packages.
-#
-# Serves as common overlay for this repository.
-#
-self: super:
+# Overlay for Nixpkgs which holds all opsqueue related packages.
+final: prev:
 let
-  sources = import ./sources.nix;
-  lib = super.pkgs.lib;
-  pythonOverlay = import ./python-overlay.nix { inherit sources; };
+  pythonOverlay = import ./python-overlay.nix;
 in
 {
-  # A powerful way of filtering the right files for the src attribute of a derivation.
-  fileFilter =
-    {
-      name,
-      # Regex whitelist of files
-      srcWhitelist ? [ ".*" ],
-      # Blacklist of files and directories anywhere in the repository. Use only
-      # with files that can appear in multiple places in the repository.
-      srcGlobalBlacklist ? [ ],
-      # Global whitelist by suffix, only allow the following file extensions
-      srcGlobalWhitelist ? [ ],
-      # Global whitelist by regex, only allow the following file extensions
-      srcGlobalWhitelistRegex ? [ ],
-      src,
-    }:
-    lib.cleanSourceWith rec {
-      inherit name src;
-      filter =
-        path: type:
-        let
-          relativePath = lib.removePrefix (toString src + "/") path;
-        in
-        (builtins.any (r: builtins.match r relativePath != null) srcWhitelist)
-        &&
-          # Whitelist these files
-          (
-            (type == "directory")
-            || (
-              (builtins.length srcGlobalWhitelist != 0)
-              && (builtins.any (suffix: lib.hasSuffix suffix relativePath) srcGlobalWhitelist)
-              || (
-                (builtins.length srcGlobalWhitelistRegex != 0)
-                && (builtins.any (r: builtins.match r relativePath != null) srcGlobalWhitelistRegex)
-              )
-            )
-          )
-        &&
-          # Ignore the files from srcGlobalBlacklist anywhere
-          !(builtins.elem (baseNameOf path) srcGlobalBlacklist)
-        &&
-          # Discard editor files, git repo stuff, and other cruft. This one is taken
-          # from Nixpkgs; we don't need to implement it ourselves.
-          lib.cleanSourceFilter path type;
-    };
-
-  # Placing the sources in the overlay gives all packages access to the sources,
-  # and it makes it possible to override them in new overlays.
-  sources = if super ? sources then super.sources // sources else sources;
-
-  opsqueue = self.callPackage ../opsqueue/opsqueue.nix { };
+  opsqueue = final.callPackage ../opsqueue/opsqueue.nix { };
 
   # The explicit choice is made not to override `python312`, as this will cause a rebuild of many
   # packages when nixpkgs uses python 3.12 as default python environment.
   # These packages should not be affected, e.g. cachix. This is because of a transitive
   # dependency on the Python packages that we override.
   # In our case cachix > ghc > shpinx > Python libraries.
-  pythonChannable = super.python312.override { packageOverrides = pythonOverlay; };
-
-  # We choose a minimal Rust channel to keep the Nix closure size smaller
-  rust-with-lsp = self.rust-bin.stable.latest.minimal.override {
-    extensions = [
-      "clippy"
-      "rustfmt"
-    ];
-  };
+  pythonChannable = prev.python312.override { packageOverrides = pythonOverlay; };
 
-  pre-commit-env = self.buildEnv {
-    name = "pre-commit-env";
-    paths = [
-      super.python3Packages.pre-commit-hooks
-      super.nixfmt-rfc-style
-      super.ruff
-      super.biome
-      self.rust-with-lsp
-    ];
-  };
 }

nix/python-overlay.nix

@@ -1,4 +1,3 @@
-{
-  sources ? import ./sources.nix,
-}:
-self: super: { opsqueue_python = self.callPackage ../libs/opsqueue_python/opsqueue_python.nix { }; }
+final: prev: {
+  opsqueue_python = final.callPackage ../libs/opsqueue_python/opsqueue_python.nix { };
+}

nix/util.nix

@@ -0,0 +1,48 @@
+# Utility functions to use in nix code
+{ lib }:
+{
+  # A powerful way of filtering the right files for the src attribute of a derivation.
+  fileFilter =
+    {
+      name,
+      # Regex whitelist of files
+      srcWhitelist ? [ ".*" ],
+      # Blacklist of files and directories anywhere in the repository. Use only
+      # with files that can appear in multiple places in the repository.
+      srcGlobalBlacklist ? [ ],
+      # Global whitelist by suffix, only allow the following file extensions
+      srcGlobalWhitelist ? [ ],
+      # Global whitelist by regex, only allow the following file extensions
+      srcGlobalWhitelistRegex ? [ ],
+      src,
+    }:
+    lib.cleanSourceWith rec {
+      inherit name src;
+      filter =
+        path: type:
+        let
+          relativePath = lib.removePrefix (toString src + "/") path;
+        in
+        (builtins.any (r: builtins.match r relativePath != null) srcWhitelist)
+        &&
+          # Whitelist these files
+          (
+            (type == "directory")
+            || (
+              (builtins.length srcGlobalWhitelist != 0)
+              && (builtins.any (suffix: lib.hasSuffix suffix relativePath) srcGlobalWhitelist)
+              || (
+                (builtins.length srcGlobalWhitelistRegex != 0)
+                && (builtins.any (r: builtins.match r relativePath != null) srcGlobalWhitelistRegex)
+              )
+            )
+          )
+        &&
+          # Ignore the files from srcGlobalBlacklist anywhere
+          !(builtins.elem (baseNameOf path) srcGlobalBlacklist)
+        &&
+          # Discard editor files, git repo stuff, and other cruft. This one is taken
+          # from Nixpkgs; we don't need to implement it ourselves.
+          lib.cleanSourceFilter path type;
+    };
+}

opsqueue/opsqueue.nix

@@ -1,6 +1,5 @@
 {
-  fileFilter,
-  pkgs,
+  lib,
   rustPlatform,
   # Building options
   buildType ? "release",
@@ -11,6 +10,10 @@
   perl,
   git,
 }:
+let
+  root = ../.;
+  util = import (root + /nix/util.nix) { inherit lib; };
+in
 rustPlatform.buildRustPackage {
   name = "opsqueue";
   inherit
@@ -20,7 +23,7 @@ rustPlatform.buildRustPackage {
     useNextest
     ;
 
-  src = fileFilter {
+  src = util.fileFilter {
     name = "opsqueue";
     src = ./.;