Add support for running a nodelocal dns cache (#3861)

* Add support for running a nodelocal dns cache After encountering dns issues in a cluster I was recently working on I noticed Kubernetes 1.13 introduced support for running a nodelocal dns cache. I believe this can usefull for more people. https://github.com/kubernetes/kubernetes/commit/73b548db06c5e293533344c5b6171e955eac9ff1 https://github.com/kubernetes/enhancements/blob/master/keps/sig-network/0030-nodelocal-dns-cache.md * Add requested changes * Add additional requested changes + documentation * Add requested changes after review * Replace incorrect variable
2026-10-31 22:46:19 -02:30 · 2018-12-10 17:28:03 -08:00
parent 7b674e0607
commit 3e3ee0aeb1
12 changed files with 223 additions and 0 deletions
@@ -0,0 +1,71 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: nodelocaldns
+  namespace: kube-system
+  labels:
+    addonmanager.kubernetes.io/mode: EnsureExists
+
+data:
+  Corefile: |
+    {{ dns_domain }}:53 {
+        errors
+        cache 30
+        reload
+        loop
+        bind {{ nodelocaldns_ip }}
+{% if secondaryclusterIP is defined and dns_mode == 'coredns_dual' %}
+        forward . {{ clusterIP }} {{ secondaryclusterIP }} {
+{% else %}
+        forward . {{ clusterIP }} {
+{% endif %}
+                force_tcp
+        }
+        prometheus :9253
+        health {{ nodelocaldns_ip }}:8080
+        }
+    in-addr.arpa:53 {
+        errors
+        cache 30
+        reload
+        loop
+        bind {{ nodelocaldns_ip }}
+{% if secondaryclusterIP is defined %}
+        forward . {{ clusterIP }} {{ secondaryclusterIP }} {
+{% else %}
+        forward . {{ clusterIP }} {
+{% endif %}
+                force_tcp
+        }
+        prometheus :9253
+        }
+    ip6.arpa:53 {
+        errors
+        cache 30
+        reload
+        loop
+        bind {{ nodelocaldns_ip }}
+{% if secondaryclusterIP is defined %}
+        forward . {{ clusterIP }} {{ secondaryclusterIP }} {
+{% else %}
+        forward . {{ clusterIP }} {
+{% endif %}
+             force_tcp
+        }
+        prometheus :9253
+        }
+    .:53 {
+        errors
+        cache 30
+        reload
+        loop
+        bind {{ nodelocaldns_ip }}
+{% if resolvconf_mode == 'host_resolvconf' and upstream_dns_servers is defined and upstream_dns_servers|length > 0 %}
+        forward . {{ upstream_dns_servers|join(' ') }} {
+{% else %}
+        forward . /etc/resolv.conf {
+{% endif %}
+                force_tcp
+        }
+        prometheus :9253
+        }