kubespray/roles/kubernetes-apps/ansible/templates/coredns-config.yml.j2

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
  labels:
      addonmanager.kubernetes.io/mode: EnsureExists
data:
  Corefile: |
{% if coredns_external_zones is defined and coredns_external_zones|length > 0 %}
{%   for block in coredns_external_zones %}
    {{ block['zones'] | join(' ') }} {
        log
        errors
{% if block['rewrite'] is defined and block['rewrite']|length > 0 %}
{% for rewrite_match in block['rewrite'] %}
        rewrite {{ rewrite_match }}
{% endfor %}
{% endif %}
        forward . {{ block['nameservers'] | join(' ') }}
        loadbalance
        cache {{ block['cache'] | default(5) }}
        reload
{% if dns_etchosts | default(None) %}
        hosts /etc/coredns/hosts {
          fallthrough
        }
{% endif %}
    }
{%   endfor %}
{% endif %}
    .:53 {
        errors
        health {
            lameduck 5s
        }
        ready
        kubernetes {{ dns_domain }} {% if enable_coredns_reverse_dns_lookups %}in-addr.arpa ip6.arpa {% endif %}{
          pods insecure
{% if enable_coredns_k8s_endpoint_pod_names %}
          endpoint_pod_names
{% endif %}
{% if enable_coredns_reverse_dns_lookups %}
          fallthrough in-addr.arpa ip6.arpa
{% endif %}
        }
        prometheus :9153
        forward . {{ upstream_dns_servers|join(' ') if upstream_dns_servers is defined and upstream_dns_servers|length > 0 else '/etc/resolv.conf' }} {
          prefer_udp
          max_concurrent 1000
{% if dns_upstream_forward_extra_opts is defined %}
{% for optname, optvalue in dns_upstream_forward_extra_opts.items() %}
          {{ optname }} {{ optvalue }}
{% endfor %}
{% endif %}
        }
{% if enable_coredns_k8s_external %}
        k8s_external {{ coredns_k8s_external_zone }}
{% endif %}
        {{ coredns_default_zone_cache_block | indent(width=8, first=False) }}
        loop
        reload
        loadbalance
{% if dns_etchosts | default(None) %}
        hosts /etc/coredns/hosts {
          fallthrough
        }
{% endif %}
    }
{% if dns_etchosts | default(None) %}
  hosts: |
    {{ dns_etchosts | indent(width=4, first=False) }}
{% endif %}