From 8239d6079a676b38bb50dc0b39806b8c00c06381 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Thu, 2 Nov 2023 10:43:08 +0100
Subject: [PATCH] no longer depend on dhcpcd for dhcp networking

---
 nix/installer.nix                     |  1 +
 nix/kexec-installer/restore_routes.py | 11 ++++++++++-
 nix/kexec-installer/test.nix          | 27 +++++++++++++++------------
 3 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/nix/installer.nix b/nix/installer.nix
index 745011c..48e7911 100644
--- a/nix/installer.nix
+++ b/nix/installer.nix
@@ -38,6 +38,7 @@
         "${pkgs.iproute2}/bin/ip -c addr"
         "${pkgs.iproute2}/bin/ip -c -6 route"
         "${pkgs.iproute2}/bin/ip -c -4 route"
+        "${pkgs.systemd}/bin/networkctl status"
       ];
     };
   };
diff --git a/nix/kexec-installer/restore_routes.py b/nix/kexec-installer/restore_routes.py
index 50363ce..c8d3bc8 100644
--- a/nix/kexec-installer/restore_routes.py
+++ b/nix/kexec-installer/restore_routes.py
@@ -47,7 +47,7 @@ def generate_networkd_units(
 ) -> None:
     directory.mkdir(exist_ok=True)
     for interface in interfaces:
-        name = f"{interface['ifname']}.network"
+        name = f"00-{interface['ifname']}.network"
         addresses = [
             f"Address = {addr['local']}/{addr['prefixlen']}"
             for addr in interface.get("addr_info", [])
@@ -76,8 +76,17 @@ def generate_networkd_units(
 MACAddress = {interface["address"]}
 
 [Network]
+# both ipv4 and ipv6
 DHCP = yes
+# link-local multicast name resolution
+LLMNR = yes
+# lets us discover the switch port we're connected to
+LLDP = yes
+# ipv6 router advertisements
 IPv6AcceptRA = yes
+# allows us to ping "nixos.local"
+MulticastDNS = yes
+
 """
         unit += "\n".join(addresses)
         unit += "\n" + "\n".join(route_sections)
diff --git a/nix/kexec-installer/test.nix b/nix/kexec-installer/test.nix
index 431480c..575b6be 100644
--- a/nix/kexec-installer/test.nix
+++ b/nix/kexec-installer/test.nix
@@ -33,10 +33,8 @@ makeTest' {
 
       services.openssh.enable = true;
 
-      networking = {
-        useNetworkd = true;
-        useDHCP = false;
-      };
+      networking.useNetworkd = true;
+      networking.useDHCP = false;
 
       users.users.root.openssh.authorizedKeys.keyFiles = [ ./ssh-keys/id_ed25519.pub ];
 
@@ -104,17 +102,17 @@ makeTest' {
 
     def ssh(cmd: list[str], check: bool = True, stdout: Optional[int] = None) -> subprocess.CompletedProcess:
         ssh_cmd = [
-          "${pkgs.openssh}/bin/ssh", 
-          "-o", "StrictHostKeyChecking=no", 
+          "${pkgs.openssh}/bin/ssh",
+          "-o", "StrictHostKeyChecking=no",
           "-o", "ConnectTimeout=1",
-          "-i", "${./ssh-keys/id_ed25519}", 
+          "-i", "${./ssh-keys/id_ed25519}",
           "-p", "2222",
           "root@127.0.0.1",
           "--"
         ] + cmd
         print(" ".join(ssh_cmd))
-        return subprocess.run(ssh_cmd, 
-                              text=True, 
+        return subprocess.run(ssh_cmd,
+                              text=True,
                               check=check,
                               stdout=stdout)
 
@@ -136,14 +134,19 @@ makeTest' {
     node1.succeed('/root/kexec/run >&2')
 
     # wait for kexec to finish
-    while ssh(["true"], check=False).returncode == 0: 
+    while ssh(["true"], check=False).returncode == 0:
         print("Waiting for kexec to finish...")
         time.sleep(1)
 
-    while ssh(["true"], check=False).returncode != 0: 
+    while ssh(["true"], check=False).returncode != 0:
         print("Waiting for node2 to come up...")
         time.sleep(1)
 
+    while ssh(["systemctl is-active restore-network"], check=False).returncode != 0:
+        print("Waiting for network to be restored...")
+        time.sleep(1)
+    ssh(["systemctl", "status", "restore-network"])
+
     print(ssh(["ip", "addr"]))
     print(ssh(["ip", "route"]))
     print(ssh(["ip", "-6", "route"]))
@@ -160,7 +163,7 @@ makeTest' {
     root_ed25519_after = ssh(["cat", "/root/.ssh/authorized_keys"], stdout=subprocess.PIPE).stdout.strip()
     assert root_ed25519_before in root_ed25519_after, f"'{root_ed25519_before}' not included in '{root_ed25519_after}'"
 
-    print(ssh(["cat", "/etc/systemd/network/eth0.network"]))
+    print(ssh(["cat", "/etc/systemd/network/00-eth0.network"]))
     ssh(["curl", "-v", "-I", f"http://10.0.2.2:{port}"])
     ssh(["curl", "-v", "-I", f"http://[fec0::2]:{port}"])