nodelocaldns: allow binding metrics address to host IP (#7748)

inventory/sample/group_vars/k8s_cluster/k8s-cluster.yml

@@ -166,6 +166,7 @@ dns_mode: coredns
 enable_nodelocaldns: true
 nodelocaldns_ip: 169.254.25.10
 nodelocaldns_health_port: 9254
+nodelocaldns_bind_metrics_host_ip: false
 # nodelocaldns_external_zones:
 # - zones:
 #   - example.com

roles/kubernetes-apps/ansible/templates/nodelocaldns-config.yml.j2

@@ -17,7 +17,7 @@ data:
         loop
         bind {{ nodelocaldns_ip }}
         forward . {{ block['nameservers'] | join(' ') }}
-        prometheus :9253
+        prometheus {% if nodelocaldns_bind_metrics_host_ip %}{$MY_HOST_IP}{% endif %}:9253
         log
 {% if dns_etchosts | default(None) %}
         hosts /etc/coredns/hosts {
@@ -39,7 +39,7 @@ data:
         forward . {{ forwardTarget }} {
             force_tcp
         }
-        prometheus :9253
+        prometheus {% if nodelocaldns_bind_metrics_host_ip %}{$MY_HOST_IP}{% endif %}:9253
         health {{ nodelocaldns_ip }}:{{ nodelocaldns_health_port }}
 {% if dns_etchosts | default(None) %}
         hosts /etc/coredns/hosts {
@@ -56,7 +56,7 @@ data:
         forward . {{ forwardTarget }} {
             force_tcp
         }
-        prometheus :9253
+        prometheus {% if nodelocaldns_bind_metrics_host_ip %}{$MY_HOST_IP}{% endif %}:9253
     }
     ip6.arpa:53 {
         errors
@@ -67,7 +67,7 @@ data:
         forward . {{ forwardTarget }} {
             force_tcp
         }
-        prometheus :9253
+        prometheus {% if nodelocaldns_bind_metrics_host_ip %}{$MY_HOST_IP}{% endif %}:9253
     }
     .:53 {
         errors
@@ -76,7 +76,7 @@ data:
         loop
         bind {{ nodelocaldns_ip }}
         forward . {{ upstreamForwardTarget }}
-        prometheus :9253
+        prometheus {% if nodelocaldns_bind_metrics_host_ip %}{$MY_HOST_IP}{% endif %}:9253
 {% if dns_etchosts | default(None) %}
         hosts /etc/coredns/hosts {
           fallthrough

roles/kubernetes-apps/ansible/templates/nodelocaldns-daemonset.yml.j2

@@ -41,6 +41,13 @@ spec:
         args: [ "-localip", "{{ nodelocaldns_ip }}", "-conf", "/etc/coredns/Corefile", "-upstreamsvc", "coredns" ]
         securityContext:
           privileged: true
+{% if nodelocaldns_bind_metrics_host_ip %}
+        env:
+          - name: MY_HOST_IP
+            valueFrom:
+              fieldRef:
+                fieldPath: status.hostIP
+{% endif %}
         ports:
         - containerPort: 53
           name: dns

roles/kubespray-defaults/defaults/main.yaml

@@ -89,6 +89,7 @@ dns_mode: coredns
 enable_nodelocaldns: true
 nodelocaldns_ip: 169.254.25.10
 nodelocaldns_health_port: 9254
+nodelocaldns_bind_metrics_host_ip: false
 
 # Should be set to a cluster IP if using a custom cluster DNS
 manual_dns_server: ""