Templates for coredns

[kvaps]

Coredns consists of 6 manifests:

# helm install foo kvaps/kubernetes --set persistence.enabled=false --set admin.job.enabled=false
# kubectl exec -ti deploy/foo-kubernetes-admin -- sh
# kubeadm init phase addon coredns -v 10 2>&1 | sed -n 's/.*Request Body: //p'
{"kind":"ConfigMap","apiVersion":"v1","metadata":{"name":"coredns","namespace":"kube-system","creationTimestamp":null},"data":{"Corefile":".:53 {\n    errors\n    health {\n       lameduck 5s\n    }\n    ready\n    kubernetes cluster.local in-addr.arpa ip6.arpa {\n       pods insecure\n       fallthrough in-addr.arpa ip6.arpa\n       ttl 30\n    }\n    prometheus :9153\n    forward . /etc/resolv.conf {\n       max_concurrent 1000\n    }\n    cache 30\n    loop\n    reload\n    loadbalance\n}\n"}}
{"kind":"ClusterRole","apiVersion":"rbac.authorization.k8s.io/v1","metadata":{"name":"system:coredns","creationTimestamp":null},"rules":[{"verbs":["list","watch"],"apiGroups":[""],"resources":["endpoints","services","pods","namespaces"]},{"verbs":["get"],"apiGroups":[""],"resources":["nodes"]}]}
{"kind":"ClusterRoleBinding","apiVersion":"rbac.authorization.k8s.io/v1","metadata":{"name":"system:coredns","creationTimestamp":null},"subjects":[{"kind":"ServiceAccount","name":"coredns","namespace":"kube-system"}],"roleRef":{"apiGroup":"rbac.authorization.k8s.io","kind":"ClusterRole","name":"system:coredns"}}
{"kind":"ServiceAccount","apiVersion":"v1","metadata":{"name":"coredns","namespace":"kube-system","creationTimestamp":null}}
{"kind":"Deployment","apiVersion":"apps/v1","metadata":{"name":"coredns","namespace":"kube-system","creationTimestamp":null,"labels":{"k8s-app":"kube-dns"}},"spec":{"replicas":2,"selector":{"matchLabels":{"k8s-app":"kube-dns"}},"template":{"metadata":{"creationTimestamp":null,"labels":{"k8s-app":"kube-dns"}},"spec":{"volumes":[{"name":"config-volume","configMap":{"name":"coredns","items":[{"key":"Corefile","path":"Corefile"}]}}],"containers":[{"name":"coredns","image":"k8s.gcr.io/coredns:1.7.0","args":["-conf","/etc/coredns/Corefile"],"ports":[{"name":"dns","containerPort":53,"protocol":"UDP"},{"name":"dns-tcp","containerPort":53,"protocol":"TCP"},{"name":"metrics","containerPort":9153,"protocol":"TCP"}],"resources":{"limits":{"memory":"170Mi"},"requests":{"cpu":"100m","memory":"70Mi"}},"volumeMounts":[{"name":"config-volume","readOnly":true,"mountPath":"/etc/coredns"}],"livenessProbe":{"httpGet":{"path":"/health","port":8080,"scheme":"HTTP"},"initialDelaySeconds":60,"timeoutSeconds":5,"successThreshold":1,"failureThreshold":5},"readinessProbe":{"httpGet":{"path":"/ready","port":8181,"scheme":"HTTP"}},"imagePullPolicy":"IfNotPresent","securityContext":{"capabilities":{"add":["NET_BIND_SERVICE"],"drop":["all"]},"readOnlyRootFilesystem":true,"allowPrivilegeEscalation":false}}],"dnsPolicy":"Default","nodeSelector":{"kubernetes.io/os":"linux"},"serviceAccountName":"coredns","tolerations":[{"key":"CriticalAddonsOnly","operator":"Exists"},{"key":"node-role.kubernetes.io/master","effect":"NoSchedule"}],"priorityClassName":"system-cluster-critical"}},"strategy":{"type":"RollingUpdate","rollingUpdate":{"maxUnavailable":1}}},"status":{}}
{"kind":"Service","apiVersion":"v1","metadata":{"name":"kube-dns","namespace":"kube-system","resourceVersion":"0","creationTimestamp":null,"labels":{"k8s-app":"kube-dns","kubernetes.io/cluster-service":"true","kubernetes.io/name":"KubeDNS"},"annotations":{"prometheus.io/port":"9153","prometheus.io/scrape":"true"}},"spec":{"ports":[{"name":"dns","protocol":"UDP","port":53,"targetPort":53},{"name":"dns-tcp","protocol":"TCP","port":53,"targetPort":53},{"name":"metrics","protocol":"TCP","port":9153,"targetPort":9153}],"selector":{"k8s-app":"kube-dns"},"clusterIP":"10.96.0.10"},"status":{"loadBalancer":{}}}

There is a need to convert them to templates, parametrize like konnectivity-agent and put into manifests directory

https://github.com/kvaps/kubernetes-in-kubernetes/blob/c181314d84f3545409cb5569599c217effbc0e6b/deploy/helm/kubernetes/values.yaml#L283-L308

Initial work started at coredns-manifests branch.