nixos/chrony: add simple test

nixos/tests/all-tests.nix

···
   cgit = handleTest ./cgit.nix {};
   charliecloud = handleTest ./charliecloud.nix {};
   chromium = (handleTestOn ["aarch64-linux" "x86_64-linux"] ./chromium.nix {}).stable or {};
+  chrony = handleTestOn ["aarch64-linux" "x86_64-linux"] ./chrony.nix {};
   chrony-ptp = handleTestOn ["aarch64-linux" "x86_64-linux"] ./chrony-ptp.nix {};
   cinnamon = handleTest ./cinnamon.nix {};
   cjdns = handleTest ./cjdns.nix {};

nixos/tests/chrony.nix

···
+import ./make-test-python.nix ({ lib, ... }:
+{
+  name = "chrony";
+
+  meta = {
+    maintainers = with lib.maintainers; [ fpletz ];
+  };
+
+  nodes = {
+    default = {
+      services.chrony.enable = true;
+    };
+    graphene-hardened = {
+      services.chrony.enable = true;
+      services.chrony.enableMemoryLocking = true;
+      environment.memoryAllocator.provider = "graphene-hardened";
+      # dhcpcd privsep is incompatible with graphene-hardened
+      networking.useNetworkd = true;
+    };
+  };
+
+  testScript = {nodes, ...} : let
+    graphene-hardened = nodes.graphene-hardened.system.build.toplevel;
+  in ''
+    default.start()
+    default.wait_for_unit('multi-user.target')
+    default.succeed('systemctl is-active chronyd.service')
+    default.succeed('${graphene-hardened}/bin/switch-to-configuration test')
+    default.succeed('systemctl is-active chronyd.service')
+  '';
+})

pkgs/tools/networking/chrony/default.nix

···
 { lib, stdenv, fetchurl, pkg-config
 , gnutls, libedit, nspr, nss, readline, texinfo
 , libcap, libseccomp, pps-tools
+, nixosTests
 }:
 
 stdenv.mkDerivation rec {
···
   '';
 
   hardeningEnable = [ "pie" ];
+
+  passthru.tests = { inherit (nixosTests) chrony chrony-ptp; };
 
   meta = with lib; {
     description = "Sets your computer's clock from time servers on the Net";