Use systemd-resolved in the containers.

If the host uses systemd-networkd and systemd-resolved too, the
containers can be resolved from the host.

roles/educontainer/tasks/setup.yml

@@ -100,6 +100,7 @@
     src: /lib/systemd/system/{{ item.src }}
     dest: /var/lib/machines/{{ contname }}00/etc/systemd/system/{{ item.dest }}
     state: link
+    follow: False
     force: yes
   loop:
     - { src: systemd-networkd.service, dest: dbus-org.freedesktop.network1.service }
@@ -108,6 +109,18 @@
     - { src: systemd-networkd-wait-online.service, dest: network-online.target.wants/systemd-networkd-wait-online.service }
   notify: enable and restart containers
 
+- name: enable systemd-resolved in containers
+  file:
+    src: /lib/systemd/system/{{ item.src }}
+    dest: /var/lib/machines/{{ contname }}00/etc/systemd/system/{{ item.dest }}
+    state: link
+    follow: False
+    force: yes
+  loop:
+    - { src: systemd-resolved.service, dest: dbus-org.freedesktop.resolve1.service }
+    - { src: systemd-resolved.service, dest: multi-user.target.wants/systemd-resolved.service }
+  notify: enable and restart containers
+
 ########
 - name: prepare local sysctl config file
   copy: