Docs: Clarify 'bind', 'dnsmasq' and 'unbound' do not work on systemd

[spuder]

I've been struggling to get consul running on ubuntu 18.04 for several days.
The learn page shows several methods for forwarding dns including:

• Bind
• Dnsmasq
• Unbound
• systemd-resolvd
• iptables

I've tried the first 3 options with no luck.
If you are running systemd, are bind dnsmasq and unbound solutions not an option? This issue seems to indicate that is the case. #4155

Please clarify that bind, dnsmasq, and unbound setup options are not an option for systems running systemd.

[hanshasselberg]

@spuder thanks for reporting! I will forward that to our education team!

[Justdoit2]

test

[blake]

Thanks for the report, @spuder. The learn guide was just updated to include instructions on how to disable systemd-resolved so that you can use these other resolvers to forward DNS to Consul.

https://learn.hashicorp.com/tutorials/consul/dns-forwarding