From 257696260c1daa7709269ee079cac557a808ebad Mon Sep 17 00:00:00 2001
From: Emery Hemingway <ehmry@posteo.net>
Date: Wed, 2 Dec 2020 13:04:15 +0100
Subject: [PATCH] tests: use config.networking.hosts not networking.extraHosts

The latter is an opaque string but IP addresses can be extracted by
hostname from the former.
---
 tests/lib/build-vms.nix | 17 ++++++++---------
 tests/networking.nix    | 14 ++++++++++----
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/tests/lib/build-vms.nix b/tests/lib/build-vms.nix
index 8224a73..1e3db3f 100644
--- a/tests/lib/build-vms.nix
+++ b/tests/lib/build-vms.nix
@@ -91,15 +91,14 @@ rec {
                 # interfaces, use the IP address corresponding to
                 # the first interface (i.e. the first network in its
                 # virtualisation.vlans option).
-                networking.extraHosts = flip concatMapStrings machines (m':
-                  let config = (getAttr m' nodes).config;
-                  in optionalString (config.networking.primaryIPAddress != "")
-                  ("${config.networking.primaryIPAddress} "
-                    + optionalString (config.networking.domain != null)
-                    "${config.networking.hostName}.${config.networking.domain} "
-                    + ''
-                      ${config.networking.hostName}
-                    ''));
+                networking.hosts = mapAttrs' (name: machine:
+                  let config = machine.config;
+                  in {
+                    name = config.networking.primaryIPAddress;
+                    value = optional (config.networking.domain != null)
+                      "${config.networking.hostName}.${config.networking.domain}"
+                      ++ [ config.networking.hostName ];
+                  }) nodes;
 
                 virtualisation.qemu.options = forEach interfacesNumbered
                   ({ fst, snd }: qemuNICFlags snd fst m.snd);
diff --git a/tests/networking.nix b/tests/networking.nix
index b3a47f3..67d0d39 100644
--- a/tests/networking.nix
+++ b/tests/networking.nix
@@ -4,13 +4,17 @@
 
     a = { pkgs, ... }: { imports = [ ../nixos-modules/hardware.nix ]; };
 
-    b = { config, pkgs, ... }: {
+    b = { config, pkgs, lib, ... }: {
       imports = [ ../nixos-modules/hardware.nix ];
       networking.interfaces.eth1.genode.stack = null;
       genode.init.children.ping = {
         inputs = with pkgs.genodePackages; [ ping ];
         configFile = let
-          ip = builtins.head config.networking.interfaces.eth1.ipv4.addresses;
+          ipA = builtins.head config.networking.interfaces.eth1.ipv4.addresses;
+          ipAddrB = with builtins;
+            head (attrNames
+              (lib.attrsets.filterAttrs (name: (any (host: host == "a")))
+                config.networking.hosts));
         in pkgs.writeText "ping.dhall" ''
           let Genode = env:DHALL_GENODE
 
@@ -25,8 +29,10 @@
                 , routes = [ Init.ServiceRoute.child "Nic" "eth1.driver" ]
                 , config = Init.Config::{
                   , attributes = toMap
-                      { interface = "${ip.address}/${toString ip.prefixLength}"
-                      , dst_ip = "192.168.1.1"
+                      { interface = "${ipA.address}/${
+                        toString ipA.prefixLength
+                      }"
+                      , dst_ip = "${ipAddrB}"
                       , period_sec = "1"
                       , count = "10"
                       , verbose = "yes"