libvirt: use custom network with dhcp-ignore-clid (fixes #2)

Author: delan

README.md

@@ -50,20 +50,6 @@ $ git clone https://github.com/servo/ci-runners.git /config
 $ /config/server/update.sh /config/server/nixos
 ```
 
-To set up libvirt:
-
-- Connect via virt-manager on another machine
-    - File > Add Connection…
-        - \> Hypervisor: QEMU/KVM
-        - \> Connect to remote host over SSH
-        - \> Username: root
-        - \> Hostname: ci0.servo.org
-        - \> Connect
-- Configure and start the “default” network for NAT
-    - Edit > Connection Details > Virtual Networks > default
-        - \> Autostart: On Boot
-        - \> Start Network
-
 To get a GITHUB_TOKEN for the monitor service:
 
 - [Create](https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/managing-your-personal-access-tokens) a [fine-grained personal access token](https://github.com/settings/personal-access-tokens/new)
@@ -77,9 +63,13 @@ To get a GITHUB_TOKEN for the monitor service:
 To set up the monitor service, run the following:
 
 ```
-$ rustup default stable
 $ zfs create tank/base
 $ zfs create tank/ci
+$ virsh net-define cinet.xml
+$ virsh net-autostart cinet
+$ virsh net-start cinet
+
+$ rustup default stable
 $ git clone https://github.com/servo/servo.git ~/servo
 $ cp /config/.env.example /config/.env
 $ vim /config/.env

cinet.xml

@@ -0,0 +1,16 @@
+<network xmlns:dnsmasq="http://libvirt.org/schemas/network/dnsmasq/1.0">
+  <name>cinet</name>
+  <uuid>f606b6fd-b1e9-452f-a491-85ec319f34de</uuid>
+  <forward mode="nat"/>
+  <bridge name="cinet" stp="on" delay="0"/>
+  <mac address="52:54:00:c3:0f:3e"/>
+  <ip address="192.168.100.1" netmask="255.255.255.0">
+    <dhcp>
+      <range start="192.168.100.100" end="192.168.100.199"/>
+    </dhcp>
+  </ip>
+  <dnsmasq:options>
+    <!-- servo/ci-runners#2; <https://gitlab.com/libvirt/libvirt/-/issues/249> -->
+    <dnsmasq:option value="dhcp-ignore-clid"/>
+  </dnsmasq:options>
+</network>

ubuntu2204.xml

@@ -132,7 +132,7 @@
     </controller>
     <interface type='network'>
       <mac address='52:54:00:b8:b3:dd'/>
-      <source network='default'/>
+      <source network='cinet'/>
       <model type='virtio'/>
       <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
     </interface>

windows10.xml

@@ -159,7 +159,7 @@
     </controller>
     <interface type='network'>
       <mac address='52:54:00:af:68:a3'/>
-      <source network='default'/>
+      <source network='cinet'/>
       <model type='virtio'/>
       <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
     </interface>