neutron-dhcp-agent is reported to be on an inexistent lxd container

[macchese]

openstack bundle 20.10

How to reproduce:
1) create a network and a subnet with dhcp enabled
2) list network agent:
 openstack network agent list
+--------------------------------------+------------------------------+---------------------+-------------------+-------+-------+----------------------------+
| ID | Agent Type | Host | Availability Zone | Alive | State | Binary |
+--------------------------------------+------------------------------+---------------------+-------------------+-------+-------+----------------------------+
| 7c967c4e-c7eb-4e03-875a-5f0182315e3e | DHCP agent | juju-ee3f63-3-lxd-1 | nova | XXX | UP | neutron-dhcp-agent |
| 7d518fe1-3686-4c35-86ee-5e5daf2a969f | Metering agent | juju-ee3f63-3-lxd-1 | None | XXX | UP | neutron-metering-agent |
| b5d6ef98-97e7-4e1e-a2fe-c4de5be64817 | Open vSwitch agent | juju-ee3f63-3-lxd-1 | None | XXX | UP | neutron-openvswitch-agent |
| dce5bcc8-f717-4a87-ab6d-9ecb506445b5 | Metadata agent | juju-ee3f63-3-lxd-1 | None | XXX | UP | neutron-metadata-agent |
| node2.maas | OVN Controller Gateway agent | node2.maas | | :-) | UP | ovn-controller |
| ea46cc06-b1cb-49f6-a86e-05e56f8f6a4c | OVN Metadata agent | node2.maas | | :-) | UP | neutron-ovn-metadata-agent |
| node4.maas | OVN Controller Gateway agent | node4.maas | | :-) | UP | ovn-controller |
| e91582e3-9b6b-4822-b131-3745cab62ba3 | OVN Metadata agent | node4.maas | | :-) | UP | neutron-ovn-metadata-agent |
| node3.maas | OVN Controller Gateway agent | node3.maas | | :-) | UP | ovn-controller |
| 84c3715e-f64a-45f9-86a0-f3863cb7c952 | OVN Metadata agent | node3.maas | | :-) | UP | neutron-ovn-metadata-agent |
| node1.maas | OVN Controller Gateway agent | node1.maas | | :-) | UP | ovn-controller |
| 5e3a36b9-9b0c-44f5-aa99-bf80e47ced66 | OVN Metadata agent | node1.maas | | :-) | UP | neutron-ovn-metadata-agent |
+--------------------------------------+------------------------------+---------------------+-------------------+-------+-------+----------------------------+

some considerations:
1) my neutron-dhcp-agent has "XXX" into the Alive field;
2) there is no neutron-dhcp-agent package installed on any host
3) neutron-dhcp-agent is reported to be installed on juju-ee3f63-3-lxd-1 host, probably a container. Looking at the list of my hosts can't find juju-ee3f63-3-lxd-1 host.

$juju list-machines
Machine State DNS Inst id Series AZ Message
0 started 172.17.2.52 node1 focal default Deployed
0/lxd/1 started 172.17.3.160 juju-ee3f63-0-lxd-1 focal default Container started
0/lxd/2 started 172.17.3.161 juju-ee3f63-0-lxd-2 focal default Container started
0/lxd/3 started 172.17.3.173 juju-ee3f63-0-lxd-3 focal default Container started
0/lxd/4 started 172.17.3.174 juju-ee3f63-0-lxd-4 focal default Container started
0/lxd/5 started 172.17.3.176 juju-ee3f63-0-lxd-5 focal default Container started
0/lxd/6 started 172.17.3.162 juju-ee3f63-0-lxd-6 focal default Container started
0/lxd/7 started 172.17.2.59 juju-ee3f63-0-lxd-7 focal default Container started
1 started 172.17.2.53 node2 focal default Deployed
1/lxd/0 started 172.17.2.56 juju-ee3f63-1-lxd-0 focal default Container started
1/lxd/1 started 172.17.3.168 juju-ee3f63-1-lxd-1 focal default Container started
1/lxd/3 started 172.17.3.177 juju-ee3f63-1-lxd-3 focal default Container started
1/lxd/4 started 172.17.3.175 juju-ee3f63-1-lxd-4 focal default Container started
1/lxd/5 started 172.17.3.163 juju-ee3f63-1-lxd-5 focal default Container started
2 started 172.17.2.54 node3 focal default Deployed
2/lxd/0 started 172.17.2.57 juju-ee3f63-2-lxd-0 focal default Container started
2/lxd/1 started 172.17.3.164 juju-ee3f63-2-lxd-1 focal default Container started
2/lxd/2 started 172.17.3.172 juju-ee3f63-2-lxd-2 focal default Container started
2/lxd/3 started 172.17.3.165 juju-ee3f63-2-lxd-3 focal default Container started
2/lxd/4 started 172.17.3.170 juju-ee3f63-2-lxd-4 focal default Container started
2/lxd/5 started 172.17.3.171 juju-ee3f63-2-lxd-5 focal default Container started
3 started 172.17.2.55 node4 focal default Deployed
3/lxd/0 started 172.17.3.159 juju-ee3f63-3-lxd-0 focal default Container started