Stop running dnsmasq service before libvirt start

In order to prevent potential configuration conflict with libvirt
restarting dnsmasq, we should stop the service prior to restarting
libvirt.

Change-Id: I16d7dc5ee5f200ff232270e0843cd3cf11542830

playbooks/roles/bifrost-create-vm-nodes/tasks/prepare_libvirt.yml

@@ -44,6 +44,19 @@
     test_sgabios_qemu == false and
     test_sgabios_misc == true
 
+# NOTE(TheJulia): In order to prevent conflicts, stop
+# dnsmasq to prevent conflicts with libvirt restarting.
+# TODO(TheJulia): We shouldn't need to do this, but the
+# libvirt dhcp instance conflicts withour specific config
+# and taking this path allows us to not refactor dhcp at
+# this moment. Our DHCP serving should be refactored
+# so we don't need to do this.
+- name: "Stop default dnsmasq service"
+  service:
+    name: dnsmasq
+    state: stopped
+  ignore_errors: true
+
 - name: ensure libvirt network is present
   virt_net:
     name: "{{ test_vm_network }}"