dns: tune cache

hosts/dns/coredns-unbound.patch

@@ -1,13 +0,0 @@
-Index: plugin.cfg
-IDEA additional info:
-Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
-<+>UTF-8
-===================================================================
-diff --git a/plugin.cfg b/plugin.cfg
---- a/plugin.cfg	(revision ddee42c974d89d9beb4ebf7b82019624fbf0c456)
-+++ b/plugin.cfg	(revision 04ba8accb25837d30a16445a1365489fe9509333)
-@@ -69,3 +69,4 @@
- whoami:whoami
- on:github.com/coredns/caddy/onevent
- sign:sign
-+unbound:github.com/coredns/unbound

hosts/dns/dns.nix

@@ -9,7 +9,12 @@
       .:53 {
         errors
         log
-        cache
+        cache {
+          success 1000000
+          denial 50000
+          prefetch 6 10m 10%
+          serve_stale
+        }
         prometheus 10.42.10.8:9253
         forward . tls://2620:fe::fe tls://9.9.9.9 tls://2620:fe::9 tls://149.112.112.112 {
           tls_servername dns.quad9.net