From: Grant Slater <git@firefishy.com>
Date: Sat, 23 Nov 2019 14:58:04 +0000 (+0000)
Subject: Add a systemd-resolved FallbackDNS list
X-Git-Url: https://git.openstreetmap.org/chef.git/commitdiff_plain/ccf9563416b85c75090157d656d7674e7a3d8b2a

Add a systemd-resolved FallbackDNS list

The default in systemd for ubuntu in 18.04 is an empty fallback
list.

Use a reasonable list:

* Cloudflare (https://1.1.1.1/)
* Quad9 without filtering (https://www.quad9.net/)
* Google (https://developers.google.com/speed/public-dns/)
1.1.1.1
9.9.9.10
8.8.8.8
2606:4700:4700::1111
2620:fe::10
2001:4860:4860::8888

List from https://git.archlinux.org/svntogit/packages.git/tree/trunk/PKGBUILD?h=packages/systemd#n103
---

diff --git a/cookbooks/networking/templates/default/resolved.conf.erb b/cookbooks/networking/templates/default/resolved.conf.erb
index f749388ef..035d692df 100644
--- a/cookbooks/networking/templates/default/resolved.conf.erb
+++ b/cookbooks/networking/templates/default/resolved.conf.erb
@@ -1,4 +1,5 @@
 [Resolve]
 DNS=<%= node[:networking][:nameservers].join(" ") %>
+FallbackDNS=1.1.1.1 9.9.9.10 8.8.8.8 2606:4700:4700::1111 2620:fe::10 2001:4860:4860::8888
 Domains=<%= node[:networking][:search].join(" ") %>
 DNSSEC=allow-downgrade