test_nodelocal_dns_ocp

01_svc.yaml

apiVersion: v1
kind: Service
metadata:
  name: dns-cache-default
  namespace: openshift-dns
  labels:
    dns.operator.openshift.io/owning-dns: default
spec:
  ports:
  - name: dns
    port: 53
    protocol: UDP
    targetPort: 53
  - name: dns-tcp
    port: 53
    protocol: TCP
    targetPort: 53
  selector:
    dns.operator.openshift.io/daemonset-dns-cache: default

02_cm.yaml

# replace 172.30.205.37 with the  svc ip of 01_svc.yaml
#
apiVersion: v1
kind: ConfigMap
metadata:
  name: dns-cache-default
  namespace: openshift-dns
  labels:
    dns.operator.openshift.io/owning-dns-cache: default
data:
  Corefile: |
    cluster.local:53 {
        errors
        cache {
                success 9984 30
                denial 9984 5
        }
        reload
        loop
        bind 169.254.20.10 172.30.205.37
        forward . 172.30.0.10 {
                force_tcp
        }
        prometheus :9153
        health 169.254.20.10:8080
        }
    in-addr.arpa:53 {
        errors
        cache 30
        reload
        loop
        bind 169.254.20.10 172.30.205.37
        forward . 172.30.0.10 {
                force_tcp
        }
        prometheus :9153
        }
    ip6.arpa:53 {
        errors
        cache 30
        reload
        loop
        bind 169.254.20.10 172.30.205.37
        forward . 172.30.0.10 {
                force_tcp
        }
        prometheus :9153
        }
    .:53 {
        errors
        cache 30
        reload
        loop
        bind 169.254.20.10 172.30.205.37
        forward . 172.30.0.10 {
                force_tcp
        }
        prometheus :9153
        }

03_ds.yaml

# replace 172.30.205.37 with the  svc ip of 01_svc.yaml
#
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: node-local-dns-default
  namespace: openshift-dns
  labels:
    dns.operator.openshift.io/owning-dns-cache: default
spec:
  updateStrategy:
    rollingUpdate:
      maxUnavailable: 10%
  selector:
    matchLabels:
      dns.operator.openshift.io/daemonset-dns-cache: default
  template:
    metadata:
       labels:
          dns.operator.openshift.io/daemonset-dns-cache: default
    spec:
      priorityClassName: system-node-critical
      serviceAccountName: dns
      hostNetwork: true
      dnsPolicy: Default  # Don't use cluster DNS.
      tolerations:
      - key: "CriticalAddonsOnly"
        operator: "Exists"
      containers:
      - name: node-cache
        image: k8s.gcr.io/k8s-dns-node-cache:1.15.7
        resources:
          requests:
            cpu: 25m
            memory: 5Mi
        args: [ "-localip", "169.254.20.10,172.30.205.37", "-conf", "/etc/Corefile", "-upstreamsvc", "dns-cache-default" ]
        securityContext:
          privileged: true
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        - containerPort: 9153
          name: metrics
          protocol: TCP
        livenessProbe:
          httpGet:
            host: 169.254.20.10
            path: /health
            port: 8080
          initialDelaySeconds: 60
          timeoutSeconds: 5
        volumeMounts:
        - mountPath: /run/xtables.lock
          name: xtables-lock
          readOnly: false
        - name: config-volume
          mountPath: /etc/coredns
        - name: kube-dns-config
          mountPath: /etc/kube-dns
      volumes:
      - name: xtables-lock
        hostPath:
          path: /run/xtables.lock
          type: FileOrCreate
      - name: kube-dns-config
        configMap:
          name: kube-dns
          optional: true
      - name: config-volume
        configMap:
          name: dns-cache-default
          items:
            - key: Corefile
              path: Corefile.base

04_dns_cahce_pod.log

# Appears that we are hitting https://github.com/kubernetes/kubernetes/issues/71305
# @danwinship has this workaround: https://github.com/kubernetes/kubernetes/issues/71305#issuecomment-521978797
# and https://github.com/danwinship/iptables-wrappers
#
$ oc logs node-local-dns-default-j5dfh -n openshift-dns
2020/01/07 02:41:50 2020-01-07T02:41:50.405Z [INFO] Using Corefile /etc/Corefile
2020/01/07 02:41:50 2020-01-07T02:41:50.407Z [INFO] Tearing down
2020/01/07 02:41:50 2020-01-07T02:41:50.594Z [INFO] Hit error during teardown - Link not found
2020/01/07 02:41:50 2020-01-07T02:41:50.594Z [INFO] Setting up networking for node cache
2020/01/07 02:41:50 2020-01-07T02:41:50.693Z [INFO] Tearing down
2020/01/07 02:41:51 2020-01-07T02:41:51.328Z [FATAL] Failed to setup - error checking rule: exit status 3: Notice: The NOTRACK target is converted into CT target in rule listing and saving.
iptables v1.6.0: can't initialize iptables table `raw': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.
, Exiting