k8s容器编排
1:k8s集群的安装
1.1 k8s的架构
除了核心组件,还有一些推荐的Add-ons:
组件名称 |
说明 |
kube-dns |
负责为整个集群提供DNS服务 |
Ingress Controller |
为服务提供外网入口 |
Heapster |
提供资源监控 |
Dashboard |
提供GUI |
Federation |
提供跨可用区的集群 |
Fluentd-elasticsearch |
提供集群日志采集、存储与查询 |
1.2:修改IP地址、主机和host解析
10.0.0.11 k8s-master 10.0.0.12 k8s-node-1 10.0.0.13 k8s-node-2
1.3:master节点安装etcd
yum install etcd -y
vim /etc/etcd/etcd.conf
6行:ETCD_LISTEN_CLIENT_URLS="[http://0.0.0.0:2379](http://0.0.0.0:2379)"
21行:ETCD_ADVERTISE_CLIENT_URLS="[http://10.0.0.11:2379](http://10.0.0.11:2379)"
systemctl start etcd.service
systemctl enable etcd.service
etcdctl set testdir/testkey0 0
etcdctl get testdir/testkey0
etcdctl -C [http://10.0.0.11:2379](http://10.0.0.11:2379) cluster-health
1.4:master节点安装kubernetes
yum install kubernetes-master.x86_64 -y
vim /etc/kubernetes/apiserver
8行: KUBE_API_ADDRESS="--insecure-bind-address=0.0.0.0"
11行:KUBE_API_PORT="--port=8080"
17行:KUBE_ETCD_SERVERS="--etcd-servers=[http://10.0.0.11:2379](http://10.0.0.11:2379)"
23行:KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"
vim /etc/kubernetes/config
22行:KUBE_MASTER="--master=[http://10.0.0.11:8080](http://10.0.0.11:8080)"
systemctl enable kube-apiserver.service
systemctl restart kube-apiserver.service
systemctl enable kube-controller-manager.service
systemctl restart kube-controller-manager.service
systemctl enable kube-scheduler.service
systemctl restart kube-scheduler.service
1.5:node节点安装kubernetes
yum install kubernetes-node.x86_64 -y
vim /etc/kubernetes/config
22行:KUBE_MASTER="--master=[http://10.0.0.11:8080](http://10.0.0.11:8080)"
vim /etc/kubernetes/kubelet
5行:KUBELET_ADDRESS="--address=0.0.0.0"
8行:KUBELET_PORT="--port=10250"
11行:KUBELET_HOSTNAME="--hostname-override=10.0.0.12"
14行:KUBELET_API_SERVER="--api-servers=[http://10.0.0.11:8080](http://10.0.0.11:8080)"
systemctl enable kubelet.service
systemctl start kubelet.service
systemctl enable kube-proxy.service
systemctl start kube-proxy.service
6:所有节点配置flannel网络
yum install flannel -y
sed -i 's#[http://127.0.0.1:2379#http://10.0.0.11:2379#g](http://127.0.0.1:2379#http://10.0.0.11:2379#g)' /etc/sysconfig/flanneld
master节点:
etcdctl mk /atomic.io/network/config '{ "Network": "172.16.0.0/16" }'
yum install docker -y
systemctl enable flanneld.service
systemctl restart flanneld.service
service docker restart
systemctl restart kube-apiserver.service
systemctl restart kube-controller-manager.service
systemctl restart kube-scheduler.service
node节点:
systemctl enable flanneld.service
systemctl restart flanneld.service
service docker restart
systemctl restart kubelet.service
systemctl restart kube-proxy.service
7:配置master为镜像仓库
#master节点
vim /etc/sysconfig/docker
OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false --registry-mirror=[https://registry.docker-cn.com](https://registry.docker-cn.com) --insecure-registry=10.0.0.11:5000'
systemctl restart docker
docker run -d -p 5000:5000 --restart=always --name registry -v /opt/myregistry:/var/lib/registry registry
#node节点
vim /etc/sysconfig/docker
OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false --insecure-registry=10.0.0.11:5000'
systemctl restart docker
2:什么是k8s,k8s有什么功能?
k8s是一个docker集群的管理工具
2.1 k8s的核心功能
自愈: 重新启动失败的容器,在节点不可用时,替换和重新调度节点上的容器,对用户定义的健康检查不响应的容器会被中止,并且在容器准备好服务之前不会把其向客户端广播。
弹性伸缩: 通过监控容器的cpu的负载值,如果这个平均高于80%,增加容器的数量,如果这个平均低于10%,减少容器的数量
服务的自动发现和负载均衡: 不需要修改您的应用程序来使用不熟悉的服务发现机制,Kubernetes 为容器提供了自己的 IP 地址和一组容器的单个 DNS 名称,并可以在它们之间进行负载均衡。
滚动升级和一键回滚: Kubernetes 逐渐部署对应用程序或其配置的更改,同时监视应用程序运行状况,以确保它不会同时终止所有实例。 如果出现问题,Kubernetes会为您恢复更改,利用日益增长的部署解决方案的生态系统。
2.2 k8s的历史
2.3 k8s的安装
yum安装 1.5
源码编译安装---难度最大 可以安装最新版
二进制安装---步骤繁琐 可以安装最新版 shell,ansible,saltstack
kubeadm 安装最容易, 网络 可以安装最新版
minikube 适合开发人员体验k8s, 网络
2.4 k8s的应用场景
k8s最适合跑微服务项目!
3:k8s常用的资源
3.1 创建pod资源
k8s yaml的主要组成
apiVersion: v1 api版本
kind: pod 资源类型
metadata: 属性
spec: 详细
k8s_pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx
labels:
app: web
spec:
containers:
- name: nginx
image: 10.0.0.11:5000/nginx:1.13
ports:
- containerPort: 80
pod资源:至少由两个容器组成,pod基础容器和业务容器组成
pod是k8s最小的资源单位
3.2 ReplicationController资源
rc:保证指定数量的pod始终存活,rc通过标签选择器来关联pod
k8s资源的常见操作:
kubectl create -f xxx.yaml
kubectl get pod|rc
kubectl describe pod nginx
kubectl delete pod nginx
或者
kubectl delete -f xxx.yaml
kubectl edit pod nginx
创建一个rc
apiVersion: v1
kind: ReplicationController
metadata:
name: nginx
spec:
replicas: 5
selector:
app: myweb
template:
metadata:
labels:
app: myweb
spec:
containers:
- name: myweb
image: 10.0.0.11:5000/nginx:1.13
ports:
- containerPort: 80
rc的滚动升级 新建一个nginx-rc1.15.yaml
升级 kubectl rolling-update nginx -f nginx-rc1.15.yaml --update-period=10s
回滚 kubectl rolling-update nginx2 -f nginx-rc.yaml --update-period=1s
3.3 service资源
service帮助pod暴露端口
创建一个service
apiVersion: v1
kind: Service
metadata:
name: myweb
spec:
type: NodePort
ports:
- port: 80
nodePort: 30000
targetPort: 80
selector:
app: myweb2
修改nodePort范围
vim /etc/kubernetes/apiserver
KUBE_API_ARGS="--service-node-port-range=3000-50000"
service默认使用iptables来实现负载均衡,新版本中推荐使用lvs(四层负载均衡)
3.4 deployment资源
有rc在滚动升级之后,会造成服务访问中断,于是k8s引入了deployment资源
创建deployment
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 3
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: 10.0.0.11:5000/nginx:1.13
ports:
- containerPort: 80
resources:
limits:
cpu: 100m
requests:
cpu: 100m
deployment升级和回滚
命令行创建deployment
kubectl run nginx --image=10.0.0.11:5000/nginx:1.13 --replicas=3 --record
命令行升级版本
kubectl set image deploy nginx nginx=10.0.0.11:5000/nginx:1.15
查看deployment所有历史版本
kubectl rollout history deployment nginx
deployment回滚到上一个版本
kubectl rollout undo deployment nginx
deployment回滚到指定版本
kubectl rollout undo deployment nginx --to-revision=2
3.5 tomcat+mysql练习
在k8s中容器之间相互访问,通过VIP地址!
4:k8s的附加组件
4.1 dns服务
安装dns服务
1:下载dns_docker镜像包
wget [http://192.168.21.201/docker_k8s_dns.tar.gz](http://192.168.21.201/docker_k8s_dns.tar.gz)
2:导入dns_docker镜像包(node2节点)
3:修改skydns-rc.yaml
spec:
nodeSelector:
kubernetes.io/hostname: k8s-node-2
containers:
4:创建dns服务
kubectl create -f skydns-rc.yaml
5:检查
kubectl get all --namespace=kube-system
6:修改所有node节点kubelet的配置文件
vim /etc/kubernetes/kubelet
KUBELET_ARGS="--cluster_dns=10.254.230.254 --cluster_domain=cluster.local"
systemctl restart kubelet
4.2 namespace命令空间
namespace做资源隔离
4.3 dashboard服务
1:上传并导入镜像,打标签
2:创建dashborad的deployment和service
3:访问[http://10.0.0.11:8080/ui/](http://10.0.0.11:8080/ui/)
5: k8s弹性伸缩
k8s弹性伸缩,需要附加插件heapster监控
5.1 安装heapster监控
1:上传并导入镜像,打标签
ls *.tar.gz
for n in `ls *.tar.gz`;do docker load -i $n ;done
docker tag docker.io/kubernetes/heapster_grafana:v2.6.0 10.0.0.11:5000/heapster_grafana:v2.6.0
docker tag docker.io/kubernetes/heapster_influxdb:v0.5 10.0.0.11:5000/heapster_influxdb:v0.5
docker tag docker.io/kubernetes/heapster:canary 10.0.0.11:5000/heapster:canary
2:上传配置文件,kubectl create -f .
3:打开dashboard验证
5.2 弹性伸缩
1:修改rc的配置文件
containers:
- name: myweb
image: 10.0.0.11:5000/nginx:1.13
ports:
- containerPort: 80
resources:
limits:
cpu: 100m
requests:
cpu: 100m
2:创建弹性伸缩规则
kubectl autoscale -n qiangge replicationcontroller myweb --max=8 --min=1 --cpu-percent=8
3:测试
ab -n 1000000 -c 40 [http://172.16.28.6/index.html](http://172.16.28.6/index.html)
扩容截图
缩容:
6:持久化存储
pv: persistent volume
pvc: persistent volume claim
6.1:安装nfs服务端(10.0.0.11)
yum install nfs-utils.x86_64 -y
mkdir /data
vim /etc/exports
/data 10.0.0.0/24(rw,async,no_root_squash,no_all_squash)
systemctl start rpcbind
systemctl start nfs
6.2:在node节点安装nfs客户端
yum install nfs-utils.x86_64 -y
showmount -e 10.0.0.11
6.3:创建pv和pvc
上传yaml配置文件,创建pv和pvc
6.4:创建mysql-rc,pod模板里使用volume
volumeMounts:
- name: mysql
mountPath: /var/lib/mysql
volumes:
- name: mysql
persistentVolumeClaim:
claimName: tomcat-mysql
6.5: 验证持久化
验证方法1:删除mysql的pod,数据库不丢
kubectl delete pod mysql-gt054
验证方法2:查看nfs服务端,是否有mysql的数据文件
7:与jenkins集成实现ci/cd
ip地址 |
服务 |
内存 |
10.0.0.11 |
kube-apiserver 8080 |
1G |
10.0.0.12 |
jenkins(tomcat + jdk) 8080 |
1G |
10.0.0.13 |
gitlab 8080,80 |
2G |
7.1: 安装gitlab并上传代码
#a:安装
wget https://mirrors.tuna.tsinghua.edu.cn/gitlab-ce/yum/el7/gitlab-ce-11.9.11-ce.0.el7.x86_64.rpm
yum localinstall gitlab-ce-11.9.11-ce.0.el7.x86_64.rpm -y
#b:配置
vim /etc/gitlab/gitlab.rb
external_url 'http://10.0.0.13'
prometheus_monitoring['enable'] = false
#c:应用并启动服务
gitlab-ctl reconfigure
#使用浏览器访问http://10.0.0.13,修改root用户密码,创建project
#上传代码到git仓库
cd /srv/
rz -E
unzip xiaoniaofeifei.zip
rm -fr xiaoniaofeifei.zip
git config --global user.name "Administrator"
git config --global user.email "admin@example.com"
git init
git remote add origin http://10.0.0.13/root/xiaoniao.git
git add .
git commit -m "Initial commit"
git push -u origin master
7.2 安装jenkins,并自动构建docker镜像
1:安装jenkins
cd /opt/
rz -E
rpm -ivh jdk-8u102-linux-x64.rpm
mkdir /app
tar xf apache-tomcat-8.0.27.tar.gz -C /app
rm -fr /app/apache-tomcat-8.0.27/webapps/*
mv jenkins.war /app/apache-tomcat-8.0.27/webapps/ROOT.war
tar xf jenkin-data.tar.gz -C /root
/app/apache-tomcat-8.0.27/bin/startup.sh
netstat -lntup
2:访问jenkins
访问[http://10.0.0.12:8080/,](http://10.0.0.12:8080/,)默认账号密码admin:123456
3:配置jenkins拉取gitlab代码凭据
a:在jenkins上生成秘钥对
ssh-keygen -t rsa
b:复制公钥粘贴gitlab上
c:jenkins上创建全局凭据
4:拉取代码测试
5:编写dockerfile并测试
#vim dockerfile
FROM 10.0.0.11:5000/nginx:1.13
add . /usr/share/nginx/html
#添加docker build构建时不add的文件 vim .dockerignore dockerfile
docker build -t xiaoniao:v1 . docker run -d -p 88:80 xiaoniao:v1
打开浏览器测试访问xiaoniaofeifei的项目
6:上传dockerfile和.dockerignore到私有仓库
git add docker .dockerignore git commit -m "fisrt commit" git push -u origin master
7:点击jenkins立即构建,自动构建docker镜像并上传到私有仓库
修改jenkins 工程配置
docker build -t 10.0.0.11:5000/test:v$BUILD_ID . docker push 10.0.0.11:5000/test:v$BUILD_ID
7.3 jenkins自动部署应用到k8s
kubectl -s 10.0.0.11:8080 get nodes
if [ -f /tmp/xiaoniao.lock ];then
docker build -t 10.0.0.11:5000/xiaoniao:v$BUILD_ID .
docker push 10.0.0.11:5000/xiaoniao:v$BUILD_ID
kubectl -s 10.0.0.11:8080 set image -n xiaoniao deploy xiaoniao xiaoniao=10.0.0.11:5000/xiaoniao:v$BUILD_ID
echo "更新成功"
else
docker build -t 10.0.0.11:5000/xiaoniao:v$BUILD_ID .
docker push 10.0.0.11:5000/xiaoniao:v$BUILD_ID
kubectl -s 10.0.0.11:8080 create namespace xiaoniao
kubectl -s 10.0.0.11:8080 run xiaoniao -n xiaoniao --image=10.0.0.11:5000/xiaoniao:v$BUILD_ID --replicas=3 --record
kubectl -s 10.0.0.11:8080 expose -n xiaoniao deployment xiaoniao --port=80 --type=NodePort
port=`kubectl -s 10.0.0.11:8080 get svc -n xiaoniao|grep -oP '(?<=80:)\d+'`
echo "你的项目地址访问是http://10.0.0.13:$port"
touch /tmp/xiaoniao.lock
fi
jenkins一键回滚
kubectl -s 10.0.0.11:8080 rollout undo -n xiaoniao deployment xiaoniao
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