alertmanager doesn't start in lxd container

Because of this:https://github.com/prometheus/alertmanager/issues/1434 it doesn't seem possible to start alertmanager in a container.

It considers 252.0.0.0/8 public space I think.

Error:
root@juju-ca59d4-0-lxd-13:~# /snap/prometheus-alertmanager/current/bin/alertmanager --web.listen-address :9093
level=info ts=2019-05-13T07:13:33.054959017Z caller=main.go:174 msg="Starting Alertmanager" version="(version=0.15.0-rc.2, branch=HEAD, revision=ec2cc57d28b66590b2429b03fdba068eae32b17a)"
level=info ts=2019-05-13T07:13:33.055077776Z caller=main.go:175 build_context="(go=go1.9, user=root@lp-xenial-amd64, date=20180611-15:17:11)"
level=info ts=2019-05-13T07:13:33.079230453Z caller=cluster.go:156 component=cluster msg="setting advertise address explicitly" addr=<nil> port=9094
level=error ts=2019-05-13T07:13:33.080026525Z caller=main.go:201 msg="Unable to initialize gossip mesh" err="create memberlist: Failed to get final advertise address: Failed to parse advertise address \"<nil>\""
root@juju-ca59d4-0-lxd-13:~# /snap/prometheus-alertmanager/current/bin/alertmanager --web.listen-address 0.0.0.0:9093
level=info ts=2019-05-13T07:13:44.556028139Z caller=main.go:174 msg="Starting Alertmanager" version="(version=0.15.0-rc.2, branch=HEAD, revision=ec2cc57d28b66590b2429b03fdba068eae32b17a)"
level=info ts=2019-05-13T07:13:44.556456028Z caller=main.go:175 build_context="(go=go1.9, user=root@lp-xenial-amd64, date=20180611-15:17:11)"
level=info ts=2019-05-13T07:13:44.57179716Z caller=cluster.go:156 component=cluster msg="setting advertise address explicitly" addr=<nil> port=9094
level=error ts=2019-05-13T07:13:44.572423434Z caller=main.go:201 msg="Unable to initialize gossip mesh" err="create memberlist: Failed to get final advertise address: Failed to parse advertise address \"<nil>\""

IPs in container:

root@juju-ca59d4-0-lxd-13:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: gre0@NONE: <NOARP> mtu 1476 qdisc noop state DOWN group default qlen 1000
    link/gre 0.0.0.0 brd 0.0.0.0
3: gretap0@NONE: <BROADCAST,MULTICAST> mtu 1462 qdisc noop state DOWN group default qlen 1000
    link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
4: erspan0@NONE: <BROADCAST,MULTICAST> mtu 1450 qdisc noop state DOWN group default qlen 1000
    link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
6674: eth0@if6675: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1410 qdisc noqueue state UP group default qlen 1000
    link/ether 00:16:3e:52:e7:7b brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 252.0.215.49/8 brd 252.255.255.255 scope global dynamic eth0
       valid_lft 3214sec preferred_lft 3214sec
    inet6 fe80::216:3eff:fe52:e77b/64 scope link
       valid_lft forever preferred_lft forever
6676: eth1@if6677: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:16:3e:0e:f5:6d brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::216:3eff:fe0e:f56d/64 scope link
       valid_lft forever preferred_lft forever