Kubernetes学习之路（七）之Coredns和Dashboard二进制部署

• 一、CoreDNS部署

在 Cluster 中，除了可以通过 Cluster IP 访问 Service，Kubernetes 还提供了更为方便的 DNS 访问。

（1）编辑coredns.yaml文件

[root@linux-node1 ~]# vim coredns.yaml
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
---
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: |
    .: {
        errors
        health
        kubernetes cluster.local. in-addr.arpa ip6.arpa {
            pods insecure
            upstream
            fallthrough in-addr.arpa ip6.arpa
        }
        prometheus :
        proxy . /etc/resolv.conf
        cache
    }
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: coredns
  namespace: kube-system
  labels:
    k8s-app: coredns
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
    kubernetes.io/name: "CoreDNS"
spec:
  replicas:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable:
  selector:
    matchLabels:
      k8s-app: coredns
  template:
    metadata:
      labels:
        k8s-app: coredns
    spec:
      serviceAccountName: coredns
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule
        - key: "CriticalAddonsOnly"
          operator: "Exists"
      containers:
      - name: coredns
        image: coredns/coredns:1.0.
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            memory: 170Mi
          requests:
            cpu: 100m
            memory: 70Mi
        args: [ "-conf", "/etc/coredns/Corefile" ]
        volumeMounts:
        - name: config-volume
          mountPath: /etc/coredns
        ports:
        - containerPort:
          name: dns
          protocol: UDP
        - containerPort:
          name: dns-tcp
          protocol: TCP
        livenessProbe:
          httpGet:
            path: /health
            port:
            scheme: HTTP
          initialDelaySeconds:
          timeoutSeconds:
          successThreshold:
          failureThreshold:
      dnsPolicy: Default
      volumes:
        - name: config-volume
          configMap:
            name: coredns
            items:
            - key: Corefile
              path: Corefile
---
apiVersion: v1
kind: Service
metadata:
  name: coredns
  namespace: kube-system
  labels:
    k8s-app: coredns
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
    kubernetes.io/name: "CoreDNS"
spec:
  selector:
    k8s-app: coredns
  clusterIP: 10.1.0.2
  ports:
  - name: dns
    port:
    protocol: UDP
  - name: dns-tcp
    port:
    protocol: TCP

（2）创建coredns

[root@linux-node1 ~]# kubectl create -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.extensions "coredns" created
service "coredns" created

（3）查看coredns服务

[root@linux-node1 ~]# kubectl get deployment -n kube-system
NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
coredns                                            1m
[root@linux-node1 ~]# kubectl get svc -n kube-system
NAME      TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
coredns   ClusterIP   10.1.0.2     <none>        /UDP,/TCP   1m

[root@linux-node1 ~]# kubectl get pod -n kube-system
NAME                       READY     STATUS    RESTARTS   AGE
coredns-77c989547b-d84n8   /       Running             2m
coredns-77c989547b-j4ms2   /       Running             2m

（4）Pod容器中进行域名解析测试

[root@linux-node1 ~]# kubectl run alpine --rm -ti --image=alpine -- /bin/sh
If you don't see a command prompt, try pressing enter.

/ # nslookup httpd-svc
nslookup: can't resolve '(null)': Name does not resolve

Name:      httpd-svc
Address : 10.1.230.129

/ # wget httpd-svc:
Connecting to httpd-svc: (10.1.230.129:)
index.html           % |********************************************************************************************************************************************|       :: ETA

• 二、Dashboard部署

从github上下载dashboard的yaml文件：https://github.com/unixhot/salt-kubernetes

[root@linux-node1 dashboard]# ll
total
-rw-r--r--  root root   Aug  : admin-user-sa-rbac.yaml
-rw-r--r--  root root  Aug  : kubernetes-dashboard.yaml
-rw-r--r--  root root   Aug  : ui-admin-rbac.yaml
-rw-r--r--  root root   Aug  : ui-read-rbac.yaml

[root@linux-node1 dashboard]# kubectl create -f .
serviceaccount "admin-user" created
clusterrolebinding.rbac.authorization.k8s.io "admin-user" created
secret "kubernetes-dashboard-certs" created
serviceaccount "kubernetes-dashboard" created
role.rbac.authorization.k8s.io "kubernetes-dashboard-minimal" created
rolebinding.rbac.authorization.k8s.io "kubernetes-dashboard-minimal" created
deployment.apps "kubernetes-dashboard" created
service "kubernetes-dashboard" created
clusterrole.rbac.authorization.k8s.io "ui-admin" created
rolebinding.rbac.authorization.k8s.io "ui-admin-binding" created
clusterrole.rbac.authorization.k8s.io "ui-read" created
rolebinding.rbac.authorization.k8s.io "ui-read-binding" created

[root@linux-node1 dashboard]# kubectl get pods  -o wide -n kube-system
NAME                                    READY     STATUS    RESTARTS   AGE       IP           NODE
coredns-77c989547b-d84n8                /       Running             55m       10.2.99.7    192.168.56.13
coredns-77c989547b-j4ms2                /       Running             55m       10.2.76.6    192.168.56.12
kubernetes-dashboard-66c9d98865-mps22   /       Running             4m        10.2.76.12   192.168.56.12

[root@linux-node1 dashboard]# kubectl get svc -n kube-system
NAME                   TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)         AGE
coredns                ClusterIP   10.1.0.2       <none>        /UDP,/TCP   56m
kubernetes-dashboard   NodePort    10.1.234.201   <none>        :/TCP   5m

从上可以看到kubernetes的dashboard服务的ip为：10.1.234.201，其映射到宿主机的端口为38974，由于master上没有部署kube-porxy，所以需要直接访问https://192.168.56.12:38974，如图：

选择令牌登陆，获取令牌的方法如下：

[root@linux-node1 dashboard]# kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | grep admin-user | awk '{print $1}')
Name:         admin-user-token-mz7p9
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name=admin-user
              kubernetes.io/service-account.uid=c2a85113-acc9-11e8-a800-000c29ce4fa7

Type:  kubernetes.io/service-account-token

Data
====
namespace:   bytes
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi11c2VyLXRva2VuLW16N3A5Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZXJ2aWNlLWFjY291bnQubmFtZSI6ImFkbWluLXVzZXIiLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC51aWQiOiJjMmE4NTExMy1hY2M5LTExZTgtYTgwMC0wMDBjMjljZTRmYTciLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6a3ViZS1zeXN0ZW06YWRtaW4tdXNlciJ9.V4aEkKDBcK4RkuXRzwdAyoJRBrxAnc8axLLxGCGiduwv5Qa0HFe2WQWtny6FI-MpUP-dzrxahWSwaFcKKvVdzfBuXTbnPDBkhcrpAuzDsL0vo-GwHAAl88n8yZ67QmBwPVWH2CBrrTwWqALAfR2wNKtrUEigg-qbTQ05slP8WmbeckfzHTeZpQqegO3fz0BNBrJqi2TFDaftPm_vWSEsPWzWE9AyvfiVwGrfc_mmzHpOyxXAQXQLxJunfklwt0kuENO6sRRJ2HGvZ6HnCGZYZj0p-kjh5uAv-q_X2cMPIAhXgH7gHdYeiSXvEGA2Qz6tBE2pgN6S4F_xj6b4JT7kAQ
ca.crt:      bytes 

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