feat(ci/cd): Set up Hydra

.hydra/jobsets.nix

@@ -0,0 +1,13 @@
+{ nixpkgs ? <nixpkgs> }:
+
+let
+
+  pkgs = import nixpkgs { };
+
+in
+
+{
+
+  myapp = pkgs.writeShellScript "hello" "${pkgs.hello}/bin/hello";
+
+}

.hydra/spec.json

@@ -0,0 +1,26 @@
+{
+  "hello": {
+    "enabled": 1,
+    "hidden": false,
+    "description": "test",
+    "nixexprinput": "src",
+    "nixexprpath": ".hydra/jobsets.nix",
+    "checkinterval": 300,
+    "schedulingshares": 100,
+    "enableemail": false,
+    "emailoverride": "",
+    "keepnr": 3,
+    "inputs": {
+      "src": {
+        "type": "git",
+        "value": "https://forgejo.stefka.eu/jiriks74/zsh.nix main",
+        "emailresponsible": false 
+      },
+      "nixpkgs": { "type": "git",
+        "type": "git",
+        "value": "https://github.com/NixOS/nixpkgs.git nixos-unstable",
+        "emailresponsible": false
+      }
+    }
+  }
+}

flake.nix

@@ -5,6 +5,11 @@
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
     flake-utils.url = "github:numtide/flake-utils";
   };
+  home-manager = {
+    url = "github:nix-community/home-manager/master";
+    inputs.nixpkgs.follows = "nixpkgs";
+  };
+
 
   outputs = {
     self,
@@ -47,5 +52,6 @@
         ];
       };
     };
+    hydraJobs = import ./hydra.nix {inherit inputs outputs;};
   };
 }

hydra.nix

@@ -0,0 +1,22 @@
+{
+  inputs,
+  outputs,
+}: let
+  inherit (inputs.nixpkgs) lib;
+
+  notBroken = pkg: !(pkg.meta.broken or false);
+  isDistributable = pkg: (pkg.meta.license or {redistributable = true;}).redistributable;
+  hasPlatform = sys: pkg: lib.elem sys (pkg.meta.platforms or [sys]);
+  filterValidPkgs = sys: pkgs:
+    lib.filterAttrs (_: pkg:
+      lib.isDerivation pkg
+      && hasPlatform sys pkg
+      && notBroken pkg
+      && isDistributable pkg)
+    pkgs;
+
+  getConfigTopLevel = _: cfg: cfg.config.system.build.toplevel;
+in {
+  pkgs = lib.mapAttrs filterValidPkgs outputs.packages;
+  hosts = lib.mapAttrs getConfigTopLevel outputs.nixosConfigurations;
+}