CoreDNS is a DNS server that chains plugins (github.com)

一、部署CoreDNS

1、下载所需要的镜像

root@k8s-master1-etcd1:~# docker pull coredns/coredns:1.8.7
root@k8s-master1-etcd1:~# docker tag docker.io/coredns/coredns:1.8.7 harbor.host.com/base/coredns:1.8.7
root@k8s-master1-etcd1:~# docker push harbor.host.com/base/coredns:1.8.7

2、下载yaml文件

CoreDNS download

root@k8s-master1-etcd1:~/kubernetes_1.23.5# ll
total 478680
drwxr-xr-x  2 root root      4096 Apr 23 19:02 ./
drwx------ 10 root root      4096 Apr 23 19:02 ../
-rw-r--r--  1 root root  26535838 Apr 23 19:01 kubernetes-client-darwin-amd64.tar.gz
-rw-r--r--  1 root root 121635346 Apr 23 19:01 kubernetes-node-linux-amd64.tar.gz
-rw-r--r--  1 root root 341423907 Apr 23 19:01 kubernetes-server-linux-amd64.tar.gz
-rw-r--r--  1 root root    554989 Apr 23 19:01 kubernetes.tar.gz

解压完后在kubernetes/cluster/addons/dns/coredns 找到coredns的yaml文件进行修改

root@k8s-master1-etcd1:~/kubernetes_1.23.5/kubernetes/cluster/addons/dns/coredns# ll
total 44
drwxr-xr-x 2 root root 4096 Mar 17 00:15 ./
drwxr-xr-x 5 root root 4096 Mar 17 00:15 ../
-rw-r--r-- 1 root root 1075 Mar 17 00:15 Makefile
-rw-r--r-- 1 root root 5060 Mar 17 00:15 coredns.yaml.base
-rw-r--r-- 1 root root 5110 Mar 17 00:15 coredns.yaml.in
-rw-r--r-- 1 root root 5112 Mar 17 00:15 coredns.yaml.sed
-rw-r--r-- 1 root root  344 Mar 17 00:15 transforms2salt.sed
-rw-r--r-- 1 root root  287 Mar 17 00:15 transforms2sed.sed
root@k8s-master1-etcd1:~/kubernetes_1.23.5/kubernetes/cluster/addons/dns/coredns# pwd

#cp coredns.yaml.base /root/yaml/coredns.yaml

3、修改部分内容如下：cat coredns.yaml根据实际情况修改

data:
  Corefile: |
    .:53 {
        errors
        health {
            lameduck 5s
        }
        ready
        kubernetes cluster.local in-addr.arpa ip6.arpa { #修改成当时部署k8s时host文件里面CLUSTER_DNS_DOMAIN对应的值，我这里是cluster.local
            pods insecure
            fallthrough in-addr.arpa ip6.arpa
            ttl 30
        }
        prometheus :9153
        forward . /etc/resolv.conf {
            max_concurrent 1000
        }
        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
    spec:
      securityContext:
        seccompProfile:
          type: RuntimeDefault
      priorityClassName: system-cluster-critical
      serviceAccountName: coredns
      affinity:
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
          - weight: 100
            podAffinityTerm:
              labelSelector:
                matchExpressions:
                  - key: k8s-app
                    operator: In
                    values: ["kube-dns"]
              topologyKey: kubernetes.io/hostname
      tolerations:
        - key: "CriticalAddonsOnly"
          operator: "Exists"
      nodeSelector:
        kubernetes.io/os: linux
      containers:
      - name: coredns
        image: harbor.host.com/base/coredns:1.8.7 #修改成自己的镜像仓库地址
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            memory: 200Mi #根据实际修改资源
          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: /ready
            port: 8181
            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: 10.100.0.2  #改成pod里面/etc/resolv.conf相同的地址
  ports:
  - name: dns
    port: 53
    protocol: UDP
  - name: dns-tcp
    port: 53
    protocol: TCP
  - name: metrics
    port: 9153
    protocol: TCP

root@k8s-master1-etcd1:~/yaml# kubectl apply -f coredns.yaml
serviceaccount/coredns created
clusterrole.rbac.authorization.k8s.io/system:coredns created
clusterrolebinding.rbac.authorization.k8s.io/system:coredns created
configmap/coredns created
deployment.apps/coredns created
service/kube-dns created

4、验证

验证容器是否启动

image.png

进入容器里面进行验证

image.png

二、官方Dashborad

部署dashbord需要用到二个镜像(changlog里查对应版本)

docker pull kubernetesui/dashboard:v2.5.1
docker pull kubernetesui/metrics-scraper:v1.0.7

下载yaml文件

wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.5.1/aio/deploy/recommended.yaml

#修改service暴露服务
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  type: NodePort #nodeport暴露
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30004  #暴露端口
  selector:
    k8s-app: kubernetes-dashboard

root@k8s-master1-etcd1:~/yaml# kubectl apply -f dashboard-v2.5.1.yaml
namespace/kubernetes-dashboard created
serviceaccount/kubernetes-dashboard created
service/kubernetes-dashboard created
secret/kubernetes-dashboard-certs created
secret/kubernetes-dashboard-csrf created
secret/kubernetes-dashboard-key-holder created
configmap/kubernetes-dashboard-settings created
role.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrole.rbac.authorization.k8s.io/kubernetes-dashboard created
rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
deployment.apps/kubernetes-dashboard created
service/dashboard-metrics-scraper created
deployment.apps/dashboard-metrics-scraper create

image.png

apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kubernetes-dashboard

kubectl apply -f admin-user.yml

拿到admin账户的token,测试登录

kubectl get secret -A | grep admin
root@k8s-master1-etcd1:~/yaml# kubectl describe secret -n kubernetes-dashboard admin-user-token-frzts

image.png