kubernetes学习(9)---安装calico、coreDNS和Metrics Server

14、安装Calico

以下步骤只在运维主机（192.168.100.50）执行

cd /data/k8s-yaml/k8s-v1-20-install/calico

修改calico-etcd.yaml的以下位置

sed -i 's#etcd_endpoints: "http://:"#etcd_endpoints: "https://192.168.100.52:2379,https://192.168.100.53:2379,https://192.168.100.54:2379,https://192.168.100.55:2379,https://192.168.100.56:2379"#g' calico-etcd.yaml

ETCD_CA=`cat /etc/kubernetes/pki/etcd/etcd-ca.pem | base64 | tr -d '\n'`
ETCD_CERT=`cat /etc/kubernetes/pki/etcd/etcd.pem | base64 | tr -d '\n'`
ETCD_KEY=`cat /etc/kubernetes/pki/etcd/etcd-key.pem | base64 | tr -d '\n'`

# 修改calico-etcd.yaml中的内容
sed -i "s@# etcd-key: null@etcd-key: ${ETCD_KEY}@g; s@# etcd-cert: null@etcd-cert: ${ETCD_CERT}@g; s@# etcd-ca: null@etcd-ca: ${ETCD_CA}@g" calico-etcd.yaml

sed -i 's#etcd_ca: ""#etcd_ca: "/calico-secrets/etcd-ca"#g; s#etcd_cert: ""#etcd_cert: "/calico-secrets/etcd-cert"#g; s#etcd_key: "" #etcd_key: "/calico-secrets/etcd-key" #g' calico-etcd.yaml

# 更改此处为自己的pod网段
POD_SUBNET="130.168.0.0/12"

注意下面的这个步骤是把calico-etcd.yaml文件里面的CALICO_IPV4POOL_CIDR下的网段改成自己的Pod网段，也就是把192.168.x.x/16改成自己的集群网段，并打开注释：

所以更改的时候请确保这个步骤的这个网段没有被统一替换掉，如果被替换掉了，还请改回来：

sed -i 's@# - name: CALICO_IPV4POOL_CIDR@- name: CALICO_IPV4POOL_CIDR@g; s@#   value: "192.168.0.0/16"@  value: '"${POD_SUBNET}"'@g' calico-etcd.yaml

• 部署calico

kubectl apply -f http://k8s-yaml.xuexi.com/calico/calico-etcd.yaml

• 查看容器状态

kubectl  get po -n kube-system

15、安装CoreDNS

在运维主机（192.168.100.50）上准备coredns.yaml文件

cd /data/k8s-yaml/k8s-v1-20-install/
mkdir -p coreDNS && chmod -R 777 coreDNS

vim coredns.yaml

内容如下：

apiVersion: v1
kind: ServiceAccount
metadata:
  name: coredns
  namespace: kube-system   # 指定名称空间
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  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
  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
data:
  Corefile: |
    .:53 {
        errors
        health {
          lameduck 5s
        }
        ready
        kubernetes cluster.local in-addr.arpa ip6.arpa {
          fallthrough in-addr.arpa ip6.arpa
        }
        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/name: "CoreDNS"
spec:
  # replicas: not specified here:
  # 1. Default is 1.
  # 2. 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:
      priorityClassName: system-cluster-critical
      serviceAccountName: coredns
      tolerations:
        - key: "CriticalAddonsOnly"
          operator: "Exists"
      nodeSelector:
        kubernetes.io/os: linux
      affinity:
         podAntiAffinity:
           preferredDuringSchedulingIgnoredDuringExecution:
           - weight: 100
             podAffinityTerm:
               labelSelector:
                 matchExpressions:
                   - key: k8s-app
                     operator: In
                     values: ["kube-dns"]
               topologyKey: kubernetes.io/hostname
      containers:
      - name: coredns
        image: harbor.xuexi.com/public/coredns:1.7.0   # 这里的coredns镜像需要自己下载，我是放到了我的harbor中
        imagePullPolicy: IfNotPresent                  # 镜像下载策略
        resources:                                     # pod需要的资源
          limits:
            memory: 170Mi
          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
        securityContext:
          allowPrivilegeEscalation: false
          capabilities:
            add:
            - NET_BIND_SERVICE
            drop:
            - all
          readOnlyRootFilesystem: true
        livenessProbe:
          httpGet:
            path: /health
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 60
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 5
        readinessProbe:
          httpGet:
            path: /ready
            port: 8181
            scheme: HTTP
      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"
    kubernetes.io/name: "CoreDNS"
spec:
  selector:
    k8s-app: kube-dns
  clusterIP: 10.96.0.10
  ports:
  - name: dns
    port: 53
    protocol: UDP
  - name: dns-tcp
    port: 53
    protocol: TCP
  - name: metrics
    port: 9153
    protocol: TCP

安装coredns

kubectl create -f http://k8s-yaml.xuexi.com/coreDNS/coredns.yaml

16、安装Metrics Server

在新版的Kubernetes中系统资源的采集均使用Metrics-server，可以通过Metrics采集节点和Pod的内存、磁盘、CPU和网络的使用率。

运维主机（172.168.100.50）上准备metric-comp.yaml文件

cd /data/k8s-yaml/k8s-v1-20-install/
mkdir -p metric-server && chmod -R 777 metric-server && cd metric-server
vim metrics-comp.yaml

内容如下

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    k8s-app: metrics-server
    rbac.authorization.k8s.io/aggregate-to-admin: "true"
    rbac.authorization.k8s.io/aggregate-to-edit: "true"
    rbac.authorization.k8s.io/aggregate-to-view: "true"
  name: system:aggregated-metrics-reader
rules:
  - apiGroups:
      - metrics.k8s.io
    resources:
      - pods
      - nodes
    verbs:
      - get
      - list
      - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    k8s-app: metrics-server
  name: system:metrics-server
rules:
  - apiGroups:
      - ""
    resources:
      - pods
      - nodes
      - nodes/stats
      - namespaces
      - configmaps
    verbs:
      - get
      - list
      - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server-auth-reader
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: extension-apiserver-authentication-reader
subjects:
  - kind: ServiceAccount
    name: metrics-server
    namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server:system:auth-delegator
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:auth-delegator
subjects:
  - kind: ServiceAccount
    name: metrics-server
    namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: system:metrics-server
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:metrics-server
subjects:
  - kind: ServiceAccount
    name: metrics-server
    namespace: kube-system
---
apiVersion: v1
kind: Service
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
spec:
  ports:
    - name: https
      port: 443
      protocol: TCP
      targetPort: https
  selector:
    k8s-app: metrics-server
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
spec:
  selector:
    matchLabels:
      k8s-app: metrics-server
  strategy:
    rollingUpdate:
      maxUnavailable: 0
  template:
    metadata:
      labels:
        k8s-app: metrics-server
    spec:
      containers:
        - args:
            - --cert-dir=/tmp
            - --secure-port=4443
            - --metric-resolution=30s
            - --kubelet-insecure-tls
            - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
            - --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.pem # change to front-proxy-ca.crt for kubeadm
            - --requestheader-username-headers=X-Remote-User
            - --requestheader-group-headers=X-Remote-Group
            - --requestheader-extra-headers-prefix=X-Remote-Extra-
          image: harbor.xuexi.com/public/metrics-server:v0.4.1     # 这个镜像还是需要自己下载
          imagePullPolicy: IfNotPresent
          livenessProbe:
            failureThreshold: 3
            httpGet:
              path: /livez
              port: https
              scheme: HTTPS
            periodSeconds: 10
          name: metrics-server
          ports:
            - containerPort: 4443
              name: https
              protocol: TCP
          readinessProbe:
            failureThreshold: 3
            httpGet:
              path: /readyz
              port: https
              scheme: HTTPS
            periodSeconds: 10
          securityContext:
            readOnlyRootFilesystem: true
            runAsNonRoot: true
            runAsUser: 1000
          volumeMounts:
            - mountPath: /tmp
              name: tmp-dir
            - name: ca-ssl
              mountPath: /etc/kubernetes/pki
      nodeSelector:
        kubernetes.io/os: linux
      priorityClassName: system-cluster-critical
      serviceAccountName: metrics-server
      volumes:
        - emptyDir: {}
          name: tmp-dir
        - name: ca-ssl
          hostPath:
            path: /etc/kubernetes/pki
---
apiVersion: apiregistration.k8s.io/v1
kind: APIService
metadata:
  labels:
    k8s-app: metrics-server
  name: v1beta1.metrics.k8s.io
spec:
  group: metrics.k8s.io
  groupPriorityMinimum: 100
  insecureSkipTLSVerify: true
  service:
    name: metrics-server
    namespace: kube-system
  version: v1beta1
  versionPriority: 100

安装metrics server

kubectl create -f http://k8s-yaml.xuexi.com/metric-server/metrics-comp.yaml

查看节点资源消耗率

kubectl top nodes
kubectl top pod -n kube-system