学习k8s（四）

1、K8S核心组件

1、Master节点:
  etcd:            分布式键值对数据库,保存集群状态
  api-server：     接受并响应用户的请求
  controller：     控制器管理,控制容器的副本数,故障检测
  scheduler：      资源调度器,选择启动容器的node节点

2、Node节点:
  kubelet：        调用docker,管理容器生命周期
  kube-proxy：     提供网络访问,负载均衡

2、k8s的安装部署

1、安装docker(所有节点)
# yum install docker-1.12.rpm
# docker pull gcr.azk8s.cn/google_containers/pause-amd64:3.0  #国内镜像服务器
# systemctl start docker

2、安装etcd(key=value数据库)
1) 安装配置
# yum install -y etcd
# vim /etc/etcd/etcd.conf
  ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
  ETCD_ADVERTISE_CLIENT_URLS="http://10.0.0.11:2379"
2) 启动服务
# systemctl start etcd.service
3) 端口检测及测试服务状态
# etcdctl set name test                                 #设置name=test
# etcdctl get name                                      #查看
# netstat -lntp | grep etcd
  2379                                                  #客户端连接端口
  2380                                                  #etcd集群连接端口

3、安装k8s-master
1) 安装配置
# yum install kubernetes-master  -y
# vim /etc/kubernetes/apiserver                         #主配置文件
  KUBE_API_ADDRESS="--insecure-bind-address=0.0.0.0"
  KUBE_API_PORT="--port=8080"
  KUBE_ETCD_SERVERS="--etcd-servers=http://10.0.0.11:2379"
  KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
  KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"
# vim /etc/kubernetes/config                            #公共配置文件
  KUBE_MASTER="--master=http://10.0.0.11:8080"
2) 启动服务
# systemctl start kube-apiserver.service
# systemctl start kube-controller-manager.service
# systemctl start kube-scheduler.service
3) 测试
# kubectl get cs                                        #检测服务是否正常

4、安装k8s-node
1) 安装配置
# yum install kubernetes-node  -y
# vim /etc/kubernetes/config                            #公共配置文件
  KUBE_MASTER="--master=http://10.0.0.11:8080"
# vim /etc/kubernetes/kubelet                           #主配置文件
  KUBELET_ADDRESS="--address=10.0.0.12"
  KUBELET_HOSTNAME="--hostname-override=10.0.0.12"
  KUBELET_API_SERVER="--api-servers=http://10.0.0.11:8080"
2) 启动服务
# systemctl start kubelet.service
# systemctl start kube-proxy.service
3) 检查服务(master节点执行)
# kubectl get nodes                                     

5、安装flannel(跨主机通信)
1) 安装配置(所有节点)
# yum install flannel -y
# vim /etc/sysconfig/flanneld
  FLANNEL_ETCD_ENDPOINTS="http://10.0.1.11:2379"
  FLANNEL_ETCD_PREFIX="/atomic.io/network"
2) 配置网络(master节点)
# etcdctl mk /atomic.io/network/config '{ "Network": "172.16.0.0/16" }'
# etcdctl get /atomic.io/network/config
3) 启动服务
# systemctl start  flanneld.service
4) 重启所有服务(所有节点)
systemctl restart kube-apiserver.service
systemctl restart kube-controller-manager.service
systemctl restart kube-scheduler.service
systemctl restart kubelet.service
systemctl restart kube-proxy.service
5) 检查服务
ifconfig flannel0

6、配置私有镜像仓库
1) 配置镜像加速和私有仓库地址(master节点)
# vim /etc/sysconfig/docker
  OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false --registry-mirror=https://registry.docker-cn.com --insecure-registry=10.0.0.11:5000'
# systemctl restart docker
2) 启动私有仓库(master节点)
# docker run -d -p 5000:5000 --restart=always --name registry -v /opt/registry:/var/lib/registry  registry
3) 推送镜像测试(node节点)
# vim /etc/sysconfig/docker
  OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false --insecure-registry=10.0.0.11:5000'
# docker tag nginx 10.0.0.11:5000/oldguo/nginx:v1
# docker push 10.0.0.11:5000/oldguo/nginx:v1
# docker images
# docker pull 10.0.0.11:5000/oldguo/nginx:v1

3、pod资源管理

1、yaml的主要组成
  apiVersion: v1        api版本
  kind: pod             资源类型
  metadata:             属性
  spec:                 详细

2、pod文件
# cat k8s_pod.yml
  apiVersion: v1
  kind: Pod
  metadata:
    name: nginx
    labels:
      app: web
  spec:
    containers:
      - name: nginx
        image: 10.0.0.11:5000/oldguonginx:v1
        ports:
          - containerPort: 80

3、pod基本操作
创建
# kubectl create –f  ks8_pod.yaml
查询
# kubectl get pod
# kubectl get pod -o wide                           #查看资源列表
# kubectl describe pod                              #详细查询
# kubectl get pods -o wide --namespace=oldguo       #查看不同命名空间的pod
删除
# kubectl delete pod nginx
# kubectl delete -f  ks8_pod.yaml
更新
# Kubectl replace ks8_pod.yaml
# kubectl replace --force -f k8s_pod.yml            #强制更新
其他
# kubectl explain pod.spec                          #yml编写帮助
# kubectl edit pod nginx                            #在线修改pod配置

4、RC资源管理

1、介绍
ReplicationController: 副本控制器,rc通过标签(metadata)选择器(selector)来管理pod
rc: 保证指定数量的pod始终存活,弹性伸缩，滚动升级

2、创建rc文件
# vim nginx-1.13-rc.yaml
  apiVersion: v1
  kind: ReplicationController
  metadata:
    name: nginx                                 #rc名
  spec:
    replicas: 3                                 #副本数
    selector:
      app: nginx                                #管理pod名
    template:
      metadata:
        labels:
          app: nginx                            #pod名
      spec:
        containers:
        - name: nginx
          image: 10.0.0.11:5000/oldguo/nginx:1.13
          ports:

3、rc的基本操作
1) 创建
# kubectl create -f nginx-1.13-rc.yaml
2) 查看
# kubectl get rc
3) 删除pod，rc会自动创建
# kubectl delete  rc nginx
4) 更新
# kuberctl edit rc nginx                        #在线修改(不常用)
# kubectl scale rc nginx --replicas=2           #修改副本数(推荐)
# kubectl replace -f nginx-1.13-rc.yaml         #更新(先删再创建,会停服,不推荐)
5) 滚动的升级和回滚
# kubectl rolling-update nginx -f nginx-1.15-rc.yaml --update-period=20s              #升级
# kubectl rolling-update nginx -f nginx-1.13-rc.yaml --update-period=10s              #回滚
# kubectl rolling-update nginx -f nginx-1.15-rc.yaml --update-period=10s --rollback   #升级中回退

5、deployment资源管理

1、介绍
拥有rc的功能,支持事件,状态查看,版本记录等

2、创建deployment文件
# vim nginx-dep.yaml
  apiVersion: extensions/v1beta1
  kind: Deployment
  metadata:
    name: nginx
  spec:
    replicas: 2
    template:
      metadata:
        labels:
          app: nginx
      spec:
        containers:
        - name: nginx
          image: 10.0.0.11:5000/oldguo/nginx:1.13
          ports:
          - containerPort: 80

3、deployment的基本操作
1) 创建
# kubectl create -f nginx-dep.yaml
# kubectl create -f nginx-dep.yaml  --record                #记录执行的步骤
2) 查看
# kubectl get deploy
3) 删除
# kubectl delete  deploy nginx
4) 更新
# kubectl scale deployment nginx --replicas=2
5) 滚动的升级和回滚
# kubectl set image deployment/nginx nginx=10.0.0.11:5000/oldguo/nginx:1.15
# kubectl rollout status deployment nginx                   #查看状态
# kubectl rollout history deployment nginx                  #查看历史状态
# kubectl rollout history deployment nginx --revision=2     #查看历史版本
# kubectl rollout undo deployment/nginx                     #回滚到上次版本
# kubectl rollout undo deployment nginx --to-revision=1     #回滚到指定版本

5、service资源管理

1、介绍
service提供了一个固定虚拟VIP,通过IP访问pod，并且提供负载均衡
Node IP -----> Cluster IP -----> Pod IP

2、创建svc配置文件
# vim nginx-svc.yml
  apiVersion: v1
  kind: Service
  metadata:
    name: nginx
  spec:
    type: NodePort
    ports:
      - port: 80
        nodePort: 30001
    selector:
      app: nginx

3、svc的基本操作
1) 创建
# kubectl create -f nginx-svc.yaml
2) 查看
# kubectl get svc
3) 删除
# kubectl delete svc nginx
4) 更新
# kubectl scale deployment nginx --replicas=2

6、持久化存储(PV和PVC)

1、创建pv文件
# vim  pv-test01.yaml
  apiVersion: v1
  kind: PersistentVolume
  metadata:
    name: test01-pv                                     #pv的名
    labels:
      pv: test01                                        #标签名
  spec:
    capacity:
      storage: 10Gi
    accessModes:
      - ReadWriteMany
    persistentVolumeReclaimPolicy: Recycle
    nfs:
      path: "/data"
      server: 10.0.0.11
      readOnly: false
# vim  pv-test02.yaml
  apiVersion: v1
  kind: PersistentVolume
  metadata:
    name: pv-test02
    labels:
      pv: test02
  spec:
    capacity:
      storage: 10Gi
    accessModes:
      - ReadWriteMany
    persistentVolumeReclaimPolicy: Recycle
    nfs:
      path: "/mysql"
      server: 10.0.0.11
      readOnly: false

2、创建pvc文件
# vim  pvc_nfs.yaml
  apiVersion: v1
  kind: PersistentVolumeClaim
  metadata:
    name: pvc_nfs                                       #pvc的名
  spec:
    accessModes:
      - ReadWriteMany
    resources:
      requests:
        storage: 1Gi
    selector:
      matchLabels:
        pv: test01                                      #绑定指定的pv(指定标签名)
# vim  pvc_mysql.yaml
  apiVersion: v1
  kind: PersistentVolumeClaim
  metadata:
    name: pvc_mysql
  spec:
    accessModes:
      - ReadWriteMany
    resources:
      requests:
        storage: 1Gi
    selector:
      matchLabels:
        pv: test02

3、创建
# kubectl create -f pv-test01.yaml
# kubectl create -f pv-test02.yaml
# kubectl create -f pvc_nfs.yaml
# kubectl create -f pvc_mysql.yaml
# kubectl get pv
# kubectl get pvc

7、wordpress项目

1、安装配置NFS
1) master节点
# yum install -y nfs-utils-*
# mkdir /data
# mkdir /code
# vim /etc/exports
  /data 10.0.0.0/24(rw,async,no_root_squash,no_all_squash)
  /code 10.0.0.0/24(rw,async,no_root_squash,no_all_squash)
# systemctl restart rpcbind
# systemctl restart nfs
# showmount -e
2) node节点
# yum install -y nfs-utils-*
# systemctl restart rpcbind
# systemctl restart nfs

2、定义pv
1) mysql的pv
# vim pv_mysql.yml
  apiVersion: v1
  kind: PersistentVolume
  metadata:
    name: pv-data
    labels:
      type: pv-mysql
  spec:
    capacity:
      storage: 10Gi
    accessModes:
      - ReadWriteMany
    persistentVolumeReclaimPolicy: Recycle
    nfs:
      path: "/data"
      server: 10.0.0.11
      readOnly: false
2) wordpress的pv
# vim pv_wp.yml
  apiVersion: v1
  kind: PersistentVolume
  metadata:
    name: pv-code
    labels:
      type: pv-wp
  spec:
    capacity:
      storage: 10Gi
    accessModes:
      - ReadWriteMany
    persistentVolumeReclaimPolicy: Recycle
    nfs:
      path: "/code"
      server: 10.0.0.11
      readOnly: false

3、定义pvc
1) mysql的pvc
# vim pvc_mysql.yml
  apiVersion: v1
  kind: PersistentVolumeClaim
  metadata:
    name: pvc-mysql
  spec:
    accessModes:
      - ReadWriteMany
    resources:
      requests:
        storage: 1Gi
    selector:
      matchLabels:
        type: pv-mysql
2) wordpress的pvc
# vim pvc_wp.yml
  apiVersion: v1
  kind: PersistentVolumeClaim
  metadata:
    name: pvc-wp
  spec:
    accessModes:
      - ReadWriteMany
    resources:
      requests:
        storage: 1Gi
    selector:
      matchLabels:
        type: pv-wp

4、创建 pv 和 pvc
# kubectl create -f pv_mysql.yml
# kubectl create -f pv_wp.yml
# kubectl create -f pvc_mysql.yml
# kubectl create -f pvc_wp.yml
# kubectl get pv
# kubectl get pvc

5、创建mysql的rc
# vim mysql-rc.yaml
  apiVersion: v1
  kind: ReplicationController
  metadata:
    name: mysql
  spec:
    replicas: 1
    selector:
      app: mysql
    template:
      metadata:
        labels:
          app: mysql
      spec:
        containers:
        - name: mysql
          image: 10.0.0.11:5000/mysql:5.7
          ports:
          - containerPort: 3306
          volumeMounts:
          - name: nfs-vol
            mountPath: /var/lib/mysql
          env:
          - name: MYSQL_ROOT_PASSWORD
            value: "123456"
          - name: MYSQL_DATABASE
            value: "wordpress"
          - name: MYSQL_USER
            value: "wordpress"
          - name: MYSQL_PASSWORD
            value: "wordpress"
        volumes:
        - name: nfs-vol
          persistentVolumeClaim:
            claimName: pvc-mysql
# kubectl create -f mysql-rc.yaml 

6、创建mysql的svc
# vim mysql-svc.yaml
  apiVersion: v1
  kind: Service
  metadata:
    name: mysql
  spec:
    ports:
      - port: 3306
    selector:
      app: mysql
# kubectl create -f mysql-svc.yaml  

7、获取 MySQL 集群 IP
# kubectl get svc
mysql        10.254.69.58     <none>        3306/TCP       28s          

8、创建wordpress的rc
# vim wp-rc.yaml
  apiVersion: v1
  kind: ReplicationController
  metadata:
    name: myweb
  spec:
    replicas: 2
    selector:
      app: myweb
    template:
      metadata:
        labels:
          app: myweb
      spec:
        containers:
        - name: myweb
          image: 10.0.0.11:5000/wordpress:latest
          ports:
          - containerPort: 80
          volumeMounts:
          - name: nfs-vol
            mountPath: /var/www/html
          env:
          - name: WORDPRESS_DB_HOST
            value: '10.254.69.58'
          - name: WORDPRESS_DB_USER
            value: 'wordpress'
          - name: WORDPRESS_DB_PASSWORD
            value: 'wordpress'
        volumes:
        - name: nfs-vol
          persistentVolumeClaim:
            claimName: pvc-wp
# kubectl create -f wp-rc.yaml             

9、创建wordpress的svc
# vim wp-svc.yaml
  apiVersion: v1
  kind: Service
  metadata:
    name: myweb
  spec:
    type: NodePort
    ports:
      - port: 80
        nodePort: 30008
    selector:
      app: myweb
# kubectl create -f wp-svc.yaml 

10、测试
浏览器访问
http://10.0.0.11:30008/