Kubernetes之使用Kubernetes部署Nginx服务

　　使用k8s部署Nginx服务,Nginx对外提供服务只希望部署在其中一台主机，该主机不提供其他服务

　　一.设置标签及污点

　　为了保证nginx之能分配到nginx服务器需要设置标签和污点，设置标签可以让Pod选择该服务器部署，设置污点可以使其他服务Pod无法部署在该服务器

　　本次部署nginx服务器IP为192.168.1.232

　　设置标签

#设置标签 key为typevalue为nginx
kubectl label node 192.168.1.232  type=nginx
#查看标签
kubectl get node 192.168.1.232 --show-labels
NAME            STATUS   ROLES    AGE   VERSION   LABELS
192.168.1.232   Ready    <none>   30h   v1.17.4   kubernetes.io/arch=amd64,kubernetes.io/hostname=192.168.1.232,kubernetes.io/os=linux,type=nginx

　　设置污点

#给node192.168.1.232设置污点key为key值为nginx effec为NoSchedule永不调度
#除非在Pod里设置了对应的tolerations参数
kubectl taint node 192.168.1.232 key=nginx:NoSchedule

　　查看污点

kubectl describe node 192.168.1.232

　　二.设置Nginx-deployment的yaml文件

# cat nginx-deployment.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx
  name: nginx-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:1.14.0
        name: nginx
      #标签选择器
      nodeSelector:
        type: nginx
      #设置污点可以调度到对应服务器
      tolerations:
      - key: "key"
        operator: "Equal"
        value: "nginx"
        effect: "NoSchedule"

　　应用启动

kubectl apply -f nginx-deployment.yaml

　　查看已经调度到对应的服务器

# kubectl get pod -o wide
NAME                                    READY   STATUS    RESTARTS   AGE     IP            NODE            NOMINATED NODE   READINESS GATES
nginx-deployment-57f94c46b4-5whb5       1/1     Running   0          6h30m   172.17.97.3   192.168.1.232   <none>           <none>

　　三.设置Nginx配置文件和程序根目录挂载

　　启动的Nginx使用默认的配置文件和默认的网站根目录，需要使用volume挂载

# cat nginx-deployment.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx
  name: nginx-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:1.14.0
        name: nginx
        volumeMounts:
        - name: conf
          mountPath: /etc/nginx
        - name: opt
          mountPath: /opt
      #标签选择器
      nodeSelector:
        type: nginx
      #设置污点可以调度到对应服务器
      tolerations:
      - key: "key"
        operator: "Equal"
        value: "nginx"
        effect: "NoSchedule"
      volumes:
      - name: conf
        hostPath:
          path: /etc/nginx
          type: Directory
      - name: opt
        hostPath:
          path: /opt
          type: Directory

　　本次使用了本机挂载hostPath挂载配置文件及根目录，生产环境最好使用pvc挂载

　　四.设置Service对外提供服务

# cat nginx-service.yaml 
apiVersion: v1
kind: Service
metadata:
  labels:
    app: nginx
  name: nginx-deployment
spec:
  ports:
  - port: 80
    name: nginx-service80
    protocol: TCP
    targetPort: 80
    nodePort: 80   
  - port: 81
    name: nginx-service81
    protocol: TCP
    targetPort: 81
    nodePort: 81 
  selector:
    app: nginx
  type: NodePort

　　PS：使用NodePort启用端口对外提供服务，如果对外映射多个端口需要在port参数下加参数name定义名称，单个端口无需设置参数name

　　 k8s默认使用NodePort对外映射端口为30000-50000如需要映射其他端口需要修改配置文件/opt/kubernetes/cfg/kube-apiserver，修改端口范围