Comment 8 for bug 1088611

--- zesty validation
# old version
$ lxc exec test-zesty -- dpkg-query --show cloud-init
cloud-init 0.7.9-153-g16a7302f-0ubuntu1~17.04.2

$ lxc exec test-zesty -- python3 -c 'import sys;
> from cloudinit.util import is_resolvable_url; print(is_resolvable_url(sys.argv[1]))' http://ubuntu.com

# dns-masq
dnsmasq[27789]: query[A] does-not-exist.example.com from 10.249.77.96
dnsmasq[27789]: forwarded does-not-exist.example.com to 127.0.0.53
dnsmasq[27789]: query[AAAA] does-not-exist.example.com from 10.249.77.96
dnsmasq[27789]: forwarded does-not-exist.example.com to 127.0.0.53
dnsmasq[27789]: query[A] rDKpshqoOwleYJvm7ByvpsJxQSUWqMh0.foo from 10.249.77.96
dnsmasq[27789]: forwarded rDKpshqoOwleYJvm7ByvpsJxQSUWqMh0.foo to 127.0.0.53
dnsmasq[27789]: query[AAAA] rDKpshqoOwleYJvm7ByvpsJxQSUWqMh0.foo from 10.249.77.96
dnsmasq[27789]: forwarded rDKpshqoOwleYJvm7ByvpsJxQSUWqMh0.foo to 127.0.0.53
dnsmasq[27789]: query[AAAA] ubuntu.com from 10.249.77.96
dnsmasq[27789]: forwarded ubuntu.com to 127.0.0.53
dnsmasq[27789]: query[A] ubuntu.com from 10.249.77.96
dnsmasq[27789]: forwarded ubuntu.com to 127.0.0.53
dnsmasq[27789]: reply ubuntu.com is 91.189.94.40

# proposed cloud-init version

$ lxc exec test-zesty -- dpkg-query --show cloud-init
cloud-init 0.7.9-233-ge586fe35-0ubuntu1~17.04.1dnsmasq[27789]: query[AAAA] does-not-exist.example.com from 10.249.77.96
dnsmasq[27789]: forwarded does-not-exist.example.com to 127.0.0.53
dnsmasq[27789]: query[A] does-not-exist.example.com from 10.249.77.96
dnsmasq[27789]: forwarded does-not-exist.example.com to 127.0.0.53
dnsmasq[27789]: query[A] __cloud_init_expected_not_found__.foo from 10.249.77.96
dnsmasq[27789]: forwarded __cloud_init_expected_not_found__.foo to 127.0.0.53
dnsmasq[27789]: query[AAAA] __cloud_init_expected_not_found__.foo from 10.249.77.96
dnsmasq[27789]: forwarded __cloud_init_expected_not_found__.foo to 127.0.0.53
dnsmasq[27789]: query[AAAA] ubuntu.com from 10.249.77.96
dnsmasq[27789]: forwarded ubuntu.com to 127.0.0.53