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 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/