k8s 1.14 coredns部署

1、文件位置：

   https://github.com/kubernetes/kubernetes/blob/master/cluster/addons/dns/coredns/coredns.yaml.base

2、

  1 # __MACHINE_GENERATED_WARNING__
  2 
  3 apiVersion: v1
  4 kind: ServiceAccount
  5 metadata:
  6   name: coredns
  7   namespace: kube-system
  8   labels:
  9       kubernetes.io/cluster-service: "true"
 10       addonmanager.kubernetes.io/mode: Reconcile
 11 ---
 12 apiVersion: rbac.authorization.k8s.io/v1
 13 kind: ClusterRole
 14 metadata:
 15   labels:
 16     kubernetes.io/bootstrapping: rbac-defaults
 17     addonmanager.kubernetes.io/mode: Reconcile
 18   name: system:coredns
 19 rules:
 20 - apiGroups:
 21   - ""
 22   resources:
 23   - endpoints
 24   - services
 25   - pods
 26   - namespaces
 27   verbs:
 28   - list
 29   - watch
 30 - apiGroups:
 31   - ""
 32   resources:
 33   - nodes
 34   verbs:
 35   - get
 36 ---
 37 apiVersion: rbac.authorization.k8s.io/v1
 38 kind: ClusterRoleBinding
 39 metadata:
 40   annotations:
 41     rbac.authorization.kubernetes.io/autoupdate: "true"
 42   labels:
 43     kubernetes.io/bootstrapping: rbac-defaults
 44     addonmanager.kubernetes.io/mode: EnsureExists
 45   name: system:coredns
 46 roleRef:
 47   apiGroup: rbac.authorization.k8s.io
 48   kind: ClusterRole
 49   name: system:coredns
 50 subjects:
 51 - kind: ServiceAccount
 52   name: coredns
 53   namespace: kube-system
 54 ---
 55 apiVersion: v1
 56 kind: ConfigMap
 57 metadata:
 58   name: coredns
 59   namespace: kube-system
 60   labels:
 61       addonmanager.kubernetes.io/mode: EnsureExists
 62 data:
 63   Corefile: |
 64     .:53 {
 65         errors
 66         health
 67         kubernetes __PILLAR__DNS__DOMAIN__ in-addr.arpa ip6.arpa {
 68             pods insecure
 69             upstream
 70             fallthrough in-addr.arpa ip6.arpa
 71             ttl 30
 72         }
 73         prometheus :9153
 74         forward . /etc/resolv.conf
 75         cache 30
 76         loop
 77         reload
 78         loadbalance
 79     }
 80 ---
 81 apiVersion: apps/v1
 82 kind: Deployment
 83 metadata:
 84   name: coredns
 85   namespace: kube-system
 86   labels:
 87     k8s-app: kube-dns
 88     kubernetes.io/cluster-service: "true"
 89     addonmanager.kubernetes.io/mode: Reconcile
 90     kubernetes.io/name: "CoreDNS"
 91 spec:
 92   # replicas: not specified here:
 93   # 1. In order to make Addon Manager do not reconcile this replicas parameter.
 94   # 2. Default is 1.
 95   # 3. Will be tuned in real time if DNS horizontal auto-scaling is turned on.
 96   strategy:
 97     type: RollingUpdate
 98     rollingUpdate:
 99       maxUnavailable: 1
100   selector:
101     matchLabels:
102       k8s-app: kube-dns
103   template:
104     metadata:
105       labels:
106         k8s-app: kube-dns
107       annotations:
108         seccomp.security.alpha.kubernetes.io/pod: 'docker/default'
109     spec:
110       priorityClassName: system-cluster-critical
111       serviceAccountName: coredns
112       tolerations:
113         - key: "CriticalAddonsOnly"
114           operator: "Exists"
115       nodeSelector:
116         beta.kubernetes.io/os: linux
117       containers:
118       - name: coredns
119         image: k8s.gcr.io/coredns:1.3.1
120         imagePullPolicy: IfNotPresent
121         resources:
122           limits:
123             memory: __PILLAR__DNS__MEMORY__LIMIT__
124           requests:
125             cpu: 100m
126             memory: 70Mi
127         args: [ "-conf", "/etc/coredns/Corefile" ]
128         volumeMounts:
129         - name: config-volume
130           mountPath: /etc/coredns
131           readOnly: true
132         ports:
133         - containerPort: 53
134           name: dns
135           protocol: UDP
136         - containerPort: 53
137           name: dns-tcp
138           protocol: TCP
139         - containerPort: 9153
140           name: metrics
141           protocol: TCP
142         livenessProbe:
143           httpGet:
144             path: /health
145             port: 8080
146             scheme: HTTP
147           initialDelaySeconds: 60
148           timeoutSeconds: 5
149           successThreshold: 1
150           failureThreshold: 5
151         readinessProbe:
152           httpGet:
153             path: /health
154             port: 8080
155             scheme: HTTP
156         securityContext:
157           allowPrivilegeEscalation: false
158           capabilities:
159             add:
160             - NET_BIND_SERVICE
161             drop:
162             - all
163           readOnlyRootFilesystem: true
164       dnsPolicy: Default
165       volumes:
166         - name: config-volume
167           configMap:
168             name: coredns
169             items:
170             - key: Corefile
171               path: Corefile
172 ---
173 apiVersion: v1
174 kind: Service
175 metadata:
176   name: kube-dns
177   namespace: kube-system
178   annotations:
179     prometheus.io/port: "9153"
180     prometheus.io/scrape: "true"
181   labels:
182     k8s-app: kube-dns
183     kubernetes.io/cluster-service: "true"
184     addonmanager.kubernetes.io/mode: Reconcile
185     kubernetes.io/name: "CoreDNS"
186 spec:
187   selector:
188     k8s-app: kube-dns
189   clusterIP: __PILLAR__DNS__SERVER__
190   ports:
191   - name: dns
192     port: 53
193     protocol: UDP
194   - name: dns-tcp
195     port: 53
196     protocol: TCP
197   - name: metrics
198     port: 9153
199     protocol: TCP

ps：大写部分需要你修改成自己k8s集群上的配置，主要修改三个地方
67行  修改成自己的域 

ps：大写部分需要你修改成自己k8s集群上的配置，主要修改三个地方
67行  大写部分修改成自己的域  一般为 cluster.local.
119行 image部分墙外的需要修改，coredns/coredns:1.3.1
123行 memory 修改成自己适合的值，我这里修改为 170Mi
189行 clusterIP 修改成kubelet.config中设置的clusterDNS IP

3、安装coredns.yaml

kubectl create -f coredns.yaml

4、验证

   4,.1 启动一个busybox pod

   注意一定要使用busybox 1.28.3，其它版本镜像有bug测试会出问题

root@k8s-master1 pv]# cat busybox.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: busybox
  namespace: default
spec:
  containers:
  - image: busybox:1.28.3
    command:
      - sleep
      - "3600"
    imagePullPolicy: IfNotPresent
    name: busybox
  restartPolicy: Always

  4.2 进入busybox 验证

[root@k8s-master2 cfg]# kubectl get svc
NAME         TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.0.0.1       <none>        443/TCP   5d15h
my-nginx     ClusterIP   10.0.140.169   <none>        80/TCP    16h

[root@k8s-master1 pv]# kubectl get po
NAME                        READY   STATUS    RESTARTS   AGE
busybox                     1/1     Running   0          5s
my-nginx-5dd67b97fb-hqg94   1/1     Running   0          42m
my-nginx-5dd67b97fb-xqj5w   1/1     Running   1          16h

[root@k8s-master1 pv]# kubectl exec -it busybox sh
/ # nslookup kubernetes.default
Server:    10.0.0.2
Address 1: 10.0.0.2 coredns.kube-system.svc.cluster.local

Name:      kubernetes.default
Address 1: 10.0.0.1 kubernetes.default.svc.cluster.local

  

# __MACHINE_GENERATED_WARNING__
	apiVersion: v1
	kind: ServiceAccount
	metadata:
	name: coredns
	namespace: kube-system
	labels:
	kubernetes.io/cluster-service: "true"
	addonmanager.kubernetes.io/mode: Reconcile
	---
	apiVersion: rbac.authorization.k8s.io/v1
	kind: ClusterRole
	metadata:
	labels:
	kubernetes.io/bootstrapping: rbac-defaults
	addonmanager.kubernetes.io/mode: Reconcile
	name: system:coredns
	rules:
	- apiGroups:
	- ""
	resources:
	- endpoints
	- services
	- pods
	- namespaces
	verbs:
	- list
	- watch
	- apiGroups:
	- ""
	resources:
	- nodes
	verbs:
	- get
	---
	apiVersion: rbac.authorization.k8s.io/v1
	kind: ClusterRoleBinding
	metadata:
	annotations:
	rbac.authorization.kubernetes.io/autoupdate: "true"
	labels:
	kubernetes.io/bootstrapping: rbac-defaults
	addonmanager.kubernetes.io/mode: EnsureExists
	name: system:coredns
	roleRef:
	apiGroup: rbac.authorization.k8s.io
	kind: ClusterRole
	name: system:coredns
	subjects:
	- kind: ServiceAccount
	name: coredns
	namespace: kube-system
	---
	apiVersion: v1
	kind: ConfigMap
	metadata:
	name: coredns
	namespace: kube-system
	labels:
	addonmanager.kubernetes.io/mode: EnsureExists
	data:
	Corefile: |
	.:53 {
	errors
	health
	kubernetes __PILLAR__DNS__DOMAIN__ in-addr.arpa ip6.arpa {
	pods insecure
	upstream
	fallthrough in-addr.arpa ip6.arpa
	ttl 30
	}
	prometheus :9153
	forward . /etc/resolv.conf
	cache 30
	loop
	reload
	loadbalance
	}
	---
	apiVersion: apps/v1
	kind: Deployment
	metadata:
	name: coredns
	namespace: kube-system
	labels:
	k8s-app: kube-dns
	kubernetes.io/cluster-service: "true"
	addonmanager.kubernetes.io/mode: Reconcile
	kubernetes.io/name: "CoreDNS"
	spec:
	# replicas: not specified here:
	# 1. In order to make Addon Manager do not reconcile this replicas parameter.
	# 2. Default is 1.
	# 3. Will be tuned in real time if DNS horizontal auto-scaling is turned on.
	strategy:
	type: RollingUpdate
	rollingUpdate:
	maxUnavailable: 1
	selector:
	matchLabels:
	k8s-app: kube-dns
	template:
	metadata:
	labels:
	k8s-app: kube-dns
	annotations:
	seccomp.security.alpha.kubernetes.io/pod: 'docker/default'
	spec:
	priorityClassName: system-cluster-critical
	serviceAccountName: coredns
	tolerations:
	- key: "CriticalAddonsOnly"
	operator: "Exists"
	nodeSelector:
	beta.kubernetes.io/os: linux
	containers:
	- name: coredns
	image: k8s.gcr.io/coredns:1.3.1
	imagePullPolicy: IfNotPresent
	resources:
	limits:
	memory: __PILLAR__DNS__MEMORY__LIMIT__
	requests:
	cpu: 100m
	memory: 70Mi
	args: [ "-conf", "/etc/coredns/Corefile" ]
	volumeMounts:
	- name: config-volume
	mountPath: /etc/coredns
	readOnly: true
	ports:
	- containerPort: 53
	name: dns
	protocol: UDP
	- containerPort: 53
	name: dns-tcp
	protocol: TCP
	- containerPort: 9153
	name: metrics
	protocol: TCP
	livenessProbe:
	httpGet:
	path: /health
	port: 8080
	scheme: HTTP
	initialDelaySeconds: 60
	timeoutSeconds: 5
	successThreshold: 1
	failureThreshold: 5
	readinessProbe:
	httpGet:
	path: /health
	port: 8080
	scheme: HTTP
	securityContext:
	allowPrivilegeEscalation: false
	capabilities:
	add:
	- NET_BIND_SERVICE
	drop:
	- all
	readOnlyRootFilesystem: true
	dnsPolicy: Default
	volumes:
	- name: config-volume
	configMap:
	name: coredns
	items:
	- key: Corefile
	path: Corefile
	---
	apiVersion: v1
	kind: Service
	metadata:
	name: kube-dns
	namespace: kube-system
	annotations:
	prometheus.io/port: "9153"
	prometheus.io/scrape: "true"
	labels:
	k8s-app: kube-dns
	kubernetes.io/cluster-service: "true"
	addonmanager.kubernetes.io/mode: Reconcile
	kubernetes.io/name: "CoreDNS"
	spec:
	selector:
	k8s-app: kube-dns
	clusterIP: __PILLAR__DNS__SERVER__
	ports:
	- name: dns
	port: 53
	protocol: UDP
	- name: dns-tcp
	port: 53
	protocol: TCP
	- name: metrics
	port: 9153
	protocol: TCP