kexec-installer: fix static ip tests

nix/kexec-installer/module.nix

@@ -98,9 +98,13 @@ in {
     wants = [ "network-pre.target" ];
     wantedBy = [ "multi-user.target" ];
 
-    serviceConfig.ExecStart = [
+    serviceConfig = {
-      "${restoreNetwork} /root/network/addrs.json /root/network/routes-v4.json /root/network/routes-v6.json"
+      Type = "oneshot";
-    ];
+      RemainAfterExit = true;
+      ExecStart = [
+        "${restoreNetwork} /root/network/addrs.json /root/network/routes-v4.json /root/network/routes-v6.json /etc/systemd/network"
+      ];
+    };
 
     unitConfig.ConditionPathExists = [
       "/root/network/addrs.json"

nix/kexec-installer/restore_routes.py

@@ -58,7 +58,7 @@ def generate_networkd_units(
             if route["dev"] != interface["ifname"]:
                 continue
 
-            route_section = "[Route]"
+            route_section = "[Route]\n"
             if route["dst"] != "default":
                 # can be skipped for default routes
                 route_section += f"Destination = {route['dst']}\n"
@@ -85,9 +85,9 @@ IPv6AcceptRA = yes
 
 
 def main() -> None:
-    if len(sys.argv) < 4:
+    if len(sys.argv) < 5:
         print(
-            f"USAGE: {sys.argv[0]} addresses routes-v4 routes-v6 [networkd-directory]",
+            f"USAGE: {sys.argv[0]} addresses routes-v4 routes-v6 networkd-directory",
             file=sys.stderr,
         )
         sys.exit(1)
@@ -99,10 +99,7 @@ def main() -> None:
     with open(sys.argv[3]) as f:
         v6_routes = json.load(f)
 
-    if len(sys.argv) >= 4:
+    networkd_directory = Path(sys.argv[4])
-        networkd_directory = Path(sys.argv[4])
-    else:
-        networkd_directory = Path("/etc/systemd/network")
 
     relevant_interfaces = filter_interfaces(addresses)
     relevant_routes = filter_routes(v4_routes) + filter_routes(v6_routes)

nix/kexec-installer/test.nix

@@ -28,14 +28,43 @@ in makeTest' {
       boot.loader.systemd-boot.enable = true;
       boot.loader.efi.canTouchEfiVariables = true;
       services.openssh.enable = true;
+
       networking = {
         useNetworkd = true;
         useDHCP = false;
       };
+
+      systemd.network = {
+        networks = {
+          # systemd-networkd will load the first network unit file
+          # that matches, ordered lexiographically by filename.
+          # /etc/systemd/network/{40-eth1,99-main}.network already
+          # exists. This network unit must be loaded for the test,
+          # however, hence why this network is named such.
+          "01-eth1" = {
+            name = "eth1";
+            address = [
+              # Some static addresses that we want to see in the kexeced image
+              "192.168.42.1/24"
+              "42::1/64"
+            ];
+            routes = [
+              # Some static routes that we want to see in the kexeced image
+              { routeConfig = { Destination = "192.168.43.0/24"; }; }
+              { routeConfig = { Destination = "192.168.44.0/24"; Gateway = "192.168.43.1"; }; }
+              { routeConfig = { Destination = "43::0/64"; }; }
+              { routeConfig = { Destination = "44::1/64"; Gateway = "43::1"; }; }
+            ];
+            networkConfig = {
+              DHCP = "yes";
+              IPv6AcceptRA = true;
+            };
+          };
+        };
+      };
     };
 
     node2 = { pkgs, modulesPath, ... }: {
-      virtualisation.vlans = [ 1 ];
       environment.systemPackages = [ pkgs.hello ];
       imports = [
         ./module.nix
@@ -59,7 +88,13 @@ in makeTest' {
           "01-eth1" = {
             name = "eth1";
             address = [
-              "2001:DB8::1/64"
+              "2001:db8::1/64"
+            ];
+            ipv6Prefixes = [
+              { ipv6PrefixConfig = { Prefix = "2001:db8::/64"; AddressAutoconfiguration = true; OnLink = true; }; }
+            ];
+            ipv6RoutePrefixes = [
+              { ipv6RoutePrefixConfig = { Route = "::/0"; LifetimeSec = 3600; }; }
             ];
             networkConfig = {
               DHCPServer = true;
@@ -69,6 +104,7 @@ in makeTest' {
             dhcpServerConfig = {
               PoolOffset = 100;
               PoolSize = 1;
+              EmitRouter = true;
             };
           };
         };
@@ -79,22 +115,24 @@ in makeTest' {
 
   testScript = { nodes, ... }: ''
     # Test whether reboot via kexec works.
-    node1.wait_for_unit("multi-user.target")
+
-    node1.succeed('kexec --load /run/current-system/kernel --initrd /run/current-system/initrd --command-line "$(</proc/cmdline)"')
+    router.wait_for_unit("network-online.target")
-    node1.execute("systemctl kexec >&2 &", check_return=False)
+    router.succeed("ip addr >&2")
-    node1.connected = False
+    router.succeed("ip route >&2")
-    node1.connect()
+    router.succeed("ip -6 route >&2")
-    node1.wait_for_unit("multi-user.target")
+    router.succeed("networkctl status eth1 >&2")
-    node1.wait_for_unit("network-online.target")
+
+    node1.wait_until_succeeds("ping -c1 10.0.0.1")
+    node1.wait_until_succeeds("ping -c1 2001:db8::1")
     node1.succeed("ip addr >&2")
     node1.succeed("ip route >&2")
     node1.succeed("ip -6 route >&2")
+    node1.succeed("networkctl status eth1 >&2")
 
-    node1.wait_for_unit("sshd.service")
     host_ed25519_before = node1.succeed("cat /etc/ssh/ssh_host_ed25519_key.pub")
-
     node1.succeed('ssh-keygen -t ed25519 -f /root/.ssh/id_ed25519 -q -N ""')
     root_ed25519_before = node1.succeed('tee /root/.ssh/authorized_keys < /root/.ssh/id_ed25519.pub')
+
     # Kexec node1 to the toplevel of node2 via the kexec-boot script
     node1.succeed('touch /run/foo')
     node1.fail('hello')
@@ -113,6 +151,37 @@ in makeTest' {
     root_ed25519_after = node1.succeed("cat /root/.ssh/authorized_keys")
     assert root_ed25519_before == root_ed25519_after, f"{root_ed25519_before} != {root_ed25519_after}"
 
+    # See if we can reach the router after kexec
+    node1.wait_for_unit("restoreNetwork.service")
+    node1.wait_until_succeeds("cat /etc/systemd/network/eth1.network >&2")
+    node1.wait_until_succeeds("ping -c1 10.0.0.1")
+    node1.wait_until_succeeds("ping -c1 2001:db8::1")
+
+    # Check if static addresses have been restored
+    node1.wait_until_succeeds("ping -c1 42::1")
+    node1.wait_until_succeeds("ping -c1 192.168.42.1")
+
+    out = node1.wait_until_succeeds("ip route get 192.168.43.2")
+    print(out)
+    assert "192.168.43.2 dev eth1" in out
+
+    out = node1.wait_until_succeeds("ip route get 192.168.44.2")
+    print(out)
+    assert "192.168.44.2 via 192.168.43.1" in out
+
+    out = node1.wait_until_succeeds("ip route get 43::2")
+    print(out)
+    assert "43::2 from :: dev eth1" in out
+
+    out = node1.wait_until_succeeds("ip route get 44::2")
+    print(out)
+    assert "44::2 from :: via 43::1" in out
+
+    node1.succeed("ip addr >&2")
+    node1.succeed("ip route >&2")
+    node1.succeed("ip -6 route >&2")
+    node1.succeed("networkctl status eth1 >&2")
+
     node1.shutdown()
   '';
 }