From a9a5b143317dfa343348ecdc80f04e1b4b118d1e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Sat, 19 Oct 2024 18:05:04 +0200
Subject: [PATCH] make nixos module hydra from this repository by default

When people reach out to the git repository they probably want to use
hydra from the same source.
This also removes the need for an overlay with simpler and more
performant direct use of the nixpkgs passed in. Before it was
re-importing nixpkgs.

test
---
 flake.nix                 | 33 +++++++++++++++------------------
 nixos-modules/default.nix | 11 +++++------
 nixos-modules/hydra.nix   |  2 --
 nixos-tests.nix           | 14 ++++++--------
 4 files changed, 26 insertions(+), 34 deletions(-)

diff --git a/flake.nix b/flake.nix
index 19381efd0..78024656e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -9,14 +9,6 @@
     let
       systems = [ "x86_64-linux" "aarch64-linux" ];
       forEachSystem = nixpkgs.lib.genAttrs systems;
-
-      overlayList = [ self.overlays.default nix.overlays.default ];
-
-      pkgsBySystem = forEachSystem (system: import nixpkgs {
-        inherit system;
-        overlays = overlayList;
-      });
-
     in
     rec {
 
@@ -30,7 +22,6 @@
       };
 
       hydraJobs = {
-
         build = forEachSystem (system: packages.${system}.hydra);
 
         buildNoTests = forEachSystem (system:
@@ -39,19 +30,21 @@
           })
         );
 
-        manual = forEachSystem (system:
-          let pkgs = pkgsBySystem.${system}; in
-          pkgs.runCommand "hydra-manual-${pkgs.hydra.version}" { }
+        manual = forEachSystem (system: let
+          pkgs = nixpkgs.legacyPackages.${system};
+          hydra = self.packages.${pkgs.hostPlatform.system}.hydra;
+        in
+          pkgs.runCommand "hydra-manual-${hydra.version}" { }
             ''
               mkdir -p $out/share
-              cp -prvd ${pkgs.hydra}/share/doc $out/share/
+              cp -prvd ${hydra}/share/doc $out/share/
 
               mkdir $out/nix-support
               echo "doc manual $out/share/doc/hydra" >> $out/nix-support/hydra-build-products
             '');
 
         tests = import ./nixos-tests.nix {
-          inherit forEachSystem nixpkgs pkgsBySystem nixosModules;
+          inherit forEachSystem nixpkgs nixosModules;
         };
 
         container = nixosConfigurations.container.config.system.build.toplevel;
@@ -64,12 +57,17 @@
       });
 
       packages = forEachSystem (system: {
-        hydra = pkgsBySystem.${system}.hydra;
-        default = pkgsBySystem.${system}.hydra;
+        hydra = nixpkgs.legacyPackages.${system}.callPackage ./package.nix {
+          inherit (nixpkgs.lib) fileset;
+          rawSrc = self;
+          nix = nix.packages.${system}.nix;
+          nix-perl-bindings = nix.hydraJobs.perlBindings.${system};
+        };
+        default = self.packages.${system}.hydra;
       });
 
       nixosModules = import ./nixos-modules {
-        overlays = overlayList;
+        inherit self;
       };
 
       nixosConfigurations.container = nixpkgs.lib.nixosSystem {
@@ -77,7 +75,6 @@
         modules =
           [
             self.nixosModules.hydra
-            self.nixosModules.overlayNixpkgsForThisHydra
             self.nixosModules.hydraTest
             self.nixosModules.hydraProxy
             {
diff --git a/nixos-modules/default.nix b/nixos-modules/default.nix
index dac705c32..62b18406a 100644
--- a/nixos-modules/default.nix
+++ b/nixos-modules/default.nix
@@ -1,11 +1,10 @@
-{ overlays }:
+{ self }:
 
 {
-  hydra = import ./hydra.nix;
-
-  overlayNixpkgsForThisHydra = { pkgs, ... }: {
-    nixpkgs = { inherit overlays; };
-    services.hydra.package = pkgs.hydra;
+  hydra = { pkgs, lib,... }: {
+    _file = ./default.nix;
+    imports = [ ./hydra.nix ];
+    services.hydra-dev.package = lib.mkDefault self.packages.${pkgs.hostPlatform.system}.hydra;
   };
 
   hydraTest = { pkgs, ... }: {
diff --git a/nixos-modules/hydra.nix b/nixos-modules/hydra.nix
index 6a2390c40..c471b0eff 100644
--- a/nixos-modules/hydra.nix
+++ b/nixos-modules/hydra.nix
@@ -68,8 +68,6 @@ in
 
       package = mkOption {
         type = types.path;
-        default = pkgs.hydra;
-        defaultText = literalExpression "pkgs.hydra";
         description = "The Hydra package.";
       };
 
diff --git a/nixos-tests.nix b/nixos-tests.nix
index 19a9ba35e..9efe68c81 100644
--- a/nixos-tests.nix
+++ b/nixos-tests.nix
@@ -1,13 +1,12 @@
-{ forEachSystem, nixpkgs, pkgsBySystem, nixosModules }:
+{ forEachSystem, nixpkgs, nixosModules }:
 
 let
   # NixOS configuration used for VM tests.
   hydraServer =
-    { config, pkgs, ... }:
+    { pkgs, ... }:
     {
       imports = [
         nixosModules.hydra
-        nixosModules.overlayNixpkgsForThisHydra
         nixosModules.hydraTest
       ];
 
@@ -44,11 +43,10 @@ in
     });
 
   notifications = forEachSystem (system:
-    let pkgs = pkgsBySystem.${system}; in
     with import (nixpkgs + "/nixos/lib/testing-python.nix") { inherit system; };
     simpleTest {
       name = "hydra-notifications";
-      nodes.machine = { pkgs, ... }: {
+      nodes.machine = {
         imports = [ hydraServer ];
         services.hydra-dev.extraConfig = ''
           <influxdb>
@@ -89,7 +87,7 @@ in
 
         # Setup the project and jobset
         machine.succeed(
-            "su - hydra -c 'perl -I ${pkgs.hydra.perlDeps}/lib/perl5/site_perl ${./t/setup-notifications-jobset.pl}' >&2"
+            "su - hydra -c 'perl -I ${config.services.hydra-dev.package.perlDeps}/lib/perl5/site_perl ${./t/setup-notifications-jobset.pl}' >&2"
         )
 
         # Wait until hydra has build the job and
@@ -103,7 +101,7 @@ in
     });
 
   gitea = forEachSystem (system:
-    let pkgs = pkgsBySystem.${system}; in
+    let pkgs = nixpkgs.legacyPackages.${system}; in
     with import (nixpkgs + "/nixos/lib/testing-python.nix") { inherit system; };
     makeTest {
       name = "hydra-gitea";
@@ -298,7 +296,7 @@ in
     });
 
   validate-openapi = forEachSystem (system:
-    let pkgs = pkgsBySystem.${system}; in
+    let pkgs = nixpkgs.legacyPackages.${system}; in
     pkgs.runCommand "validate-openapi"
     { buildInputs = [ pkgs.openapi-generator-cli ]; }
     ''