I ran lxd in debug mode and tried to start caddy again:
DBUG[08-29|16:58:30] Handling method=GET url=/1.0 ip=@ user=
DBUG[08-29|16:58:30] Handling user= method=GET url=/1.0/instances/caddy ip=@
DBUG[08-29|16:58:30] Handling method=GET url=/1.0/events ip=@ user=
DBUG[08-29|16:58:30] New event listener: d4128cd5-ff31-41e6-b4c0-e5d7f4fa349f
DBUG[08-29|16:58:30] Handling method=PUT url=/1.0/instances/caddy/state ip=@ user=
DBUG[08-29|16:58:30]
{
"action": "start",
"timeout": 0,
"force": false,
"stateful": false
}
DBUG[08-29|16:58:30] New task Operation: cfc425f7-0447-4dea-9531-a7b38a513c5c
DBUG[08-29|16:58:30] Started task operation: cfc425f7-0447-4dea-9531-a7b38a513c5c
DBUG[08-29|16:58:30]
{
"type": "async",
"status": "Operation created",
"status_code": 100,
"operation": "/1.0/operations/cfc425f7-0447-4dea-9531-a7b38a513c5c",
"error_code": 0,
"error": "",
"metadata": {
"id": "cfc425f7-0447-4dea-9531-a7b38a513c5c",
"class": "task",
"description": "Starting container",
"created_at": "2020-08-29T16:58:30.989650923-06:00",
"updated_at": "2020-08-29T16:58:30.989650923-06:00",
"status": "Running",
"status_code": 103,
"resources": {
"containers": [
"/1.0/containers/caddy"
]
},
"metadata": null,
"may_cancel": false,
"err": "",
"location": "none"
}
}
DBUG[08-29|16:58:30] Handling method=GET url=/1.0/operations/cfc425f7-0447-4dea-9531-a7b38a513c5c ip=@ user=
DBUG[08-29|16:58:30] Scheduler: network: vethfffb2f26 has been added: updating network priorities
DBUG[08-29|16:58:31] Scheduler: network: veth3a4a26a4 has been added: updating network priorities
DBUG[08-29|16:58:31] MountInstance started driver=zfs pool=default project=default instance=caddy
DBUG[08-29|16:58:31] MountInstance finished driver=zfs pool=default project=default instance=caddy
DBUG[08-29|16:58:31] UpdateInstanceBackupFile started driver=zfs pool=default instance=caddy project=default
DBUG[08-29|16:58:31] UpdateInstanceBackupFile finished driver=zfs pool=default instance=caddy project=default
DBUG[08-29|16:58:31] MountInstance started driver=zfs pool=default instance=caddy project=default
DBUG[08-29|16:58:31] MountInstance finished driver=zfs pool=default instance=caddy project=default
INFO[08-29|16:58:31] Starting container project=default name=caddy action=start created=2020-06-26T13:06:15-0600 ephemeral=false used=2020-08-28T14:54:43-0600 stateful=false
DBUG[08-29|16:58:31] Handling method=GET url=/internal/containers/24/onstart ip=@ user=
DBUG[08-29|16:58:31] MountInstance started pool=default driver=zfs project=default instance=caddy
DBUG[08-29|16:58:31] MountInstance finished pool=default driver=zfs project=default instance=caddy
EROR[08-29|16:58:31] The start hook failed container=caddy err="Failed to run: apparmor_parser --version: "
DBUG[08-29|16:58:31] Handling method=GET url="/internal/containers/24/onstopns?target=stop&netns=" ip=@ user=
DBUG[08-29|16:58:31] Stopping device device=eth0 project=default instance=caddy
DBUG[08-29|16:58:31] Clearing instance firewall static filters ipv6=:: project=default instance=caddy parent=lxdbr0 dev=eth0 host_name=veth3a4a26a4 hwaddr=00:16:3e:24:7b:21 ipv4=0.0.0.0
DBUG[08-29|16:58:31] Clearing instance firewall dynamic filters project=default instance=caddy parent=lxdbr0 dev=eth0 host_name=veth3a4a26a4 hwaddr=00:16:3e:24:7b:21 ipv4=<nil> ipv6=<nil>
DBUG[08-29|16:58:31] Stopping device device=root project=default instance=caddy
DBUG[08-29|16:58:31] Stopping device project=default instance=caddy device=httpport
DBUG[08-29|16:58:31] Stopping device device=httpsport project=default instance=caddy
DBUG[08-29|16:58:31] Handling method=GET url="/internal/containers/24/onstop?target=stop" ip=@ user=
EROR[08-29|16:58:31] The stop hook failed err="Container is already running a start operation" container=caddy
EROR[08-29|16:58:31] Failed starting container project=default name=caddy action=start created=2020-06-26T13:06:15-0600 ephemeral=false used=2020-08-28T14:54:43-0600 stateful=false
DBUG[08-29|16:58:31] Failure for task operation: cfc425f7-0447-4dea-9531-a7b38a513c5c: Failed to run: /usr/sbin/lxd forkstart caddy /var/lib/lxd/containers /var/log/lxd/caddy/lxc.conf:
DBUG[08-29|16:58:31] Event listener finished: d4128cd5-ff31-41e6-b4c0-e5d7f4fa349f
DBUG[08-29|16:58:31] Disconnected event listener: d4128cd5-ff31-41e6-b4c0-e5d7f4fa349f
This might be a duplicate of: LXD 4.4 -- container doesn't start unless apparmor is installed