08.kubernetes笔记 Service(二) Endpoint Controller、修改iptable为ipvs模式 kubernetes运维容器

Endpoint Controller简介

前面有提到管理后端端点与svc的绑定,根据标签选择器,筛选适配的pod,监控就绪的pod 并完成svc与pod的绑定
实际应用中可以自动创建一个Endpoint Controller把外部的节点管理起来相当于所外部的服务引入到内部然后绑定到svc 集群内部就可以以访问内部svc一样访问到外部的服务

资源规范

apiVersion: v1 kind: Endpoint metadata: # 对象元数据 name : namespace: subsets:#端点对象的列表 - addresses: #处于“就绪”状态的端点地址对象列表 - hostname#端点主机名 ip#端点的IP地址，必选字段 hostname或IP给其中一个就行 nodeName# 节点主机名 targetRef: #提供了该端点的对象引用 apiVersion# 被引用对象所属的API群组及版本 kind# 被引用对象的资源类型，多为Pod name# 对象名称 namespace# 对象所属的名称究竟 fieldPath#被引用的对象的字段，在未引用整个对象时使用，常用于仅引用 # 指定Pod对象中的单容器，例如spec . containers[1] uid#对象的标识符; notReadyAddresses: #处于“未就绪”状态的端点地址对象列表,格式与address相同 ports: # 端口对象列表 - name#端口名称; port # 端口号，必选字段; protocol#协议类型，仅支持UDP、TCP和SCTP，默认为TCP; appProtocol# 应用层协议;

Endpoints详情

[root@k8s-master svc]# kubectl get endpoints NAMEENDPOINTSAGE demoapp-externalip-svc10.244.1.102:80,10.244.1.103:80,10.244.2.97:80 + 1 more...9m36s demoapp-loadbalancer-svc10.244.1.102:80,10.244.1.103:80,10.244.2.97:80 + 1 more...3h15m demoapp-nodeport-svc10.244.1.102:80,10.244.1.103:80,10.244.2.97:80 + 1 more...3h45m demoapp-svc10.244.1.102:80,10.244.1.103:80,10.244.2.97:80 + 1 more...4h57m[root@k8s-master svc]# kubectl describe ep demoapp-svc Name:demoapp-svc Namespace:default Labels: Annotations:endpoints.kubernetes.io/last-change-trigger-time: 2021-07-28T19:22:06Z Subsets: Addresses:10.244.1.102,10.244.1.103,10.244.2.97,10.244.2.99#绑定的后端Pod地址 NotReadyAddresses:#所有归类到未就绪后端端点都不会接受流量 Ports: NamePortProtocol ---------------- http80TCP

示例1: Endpoints引入外部服务
1.通过Endpoints把192.168.4.100、192.168.4.254 http引入到k8s集权内部并绑定svc
2.这里httpd服务为外部服务无法通过API service来检测就绪状态,需要手动配置

[root@k8s-master svc]# cat http-endpoints-demo.yaml apiVersion: v1 kind: Endpoints metadata: name: http-external namespace: default subsets: - addresses:#外部服务地址 - ip: 192.168.4.100 - ip: 192.168.4.254 ports: - name: http port: 80 protocol: TCP notReadyAddresses: --- apiVersion: v1 kind: Service metadata: name: http-external#通过name匹配不在需要用标签选择器在同一名称空间下 name 一致就会相互匹配 namespace: default spec: type: ClusterIP ports: - name: http protocol: TCP port: 80 targetPort: 80root@k8s-master svc]# kubectl apply -f http-endpoints-demo.yaml endpoints/http-external created service/http-external created[root@k8s-master svc]# kubectl describe svc http-external Name:http-external Namespace:default Labels: Annotations: Selector: Type:ClusterIP IP:10.103.125.128#svc IP Port:http80/TCP TargetPort:80/TCP Endpoints:192.168.4.100:80,192.168.4.254:80 Session Affinity:None Events:#访问测试 [root@k8s-master svc]# while true; docurl 10.103.125.128; sleep 1; done 192.168.4.254 192.168.4.100 192.168.4.100 192.168.4.254 192.168.4.100 192.168.4.254 192.168.4.100

iptable、ipvs代理模式

iptable代理模式:
1. iptables代理模式下的ClusterIP，每个Service在每个节点上（由kube-proxy负责生成)）都会生成相应的iptables规则
2. iptables 用户空间-->ptables(内核完成数据调度)-->调度给用户空间效率高在iptables模型下kube-proxy的作用不在是数据调度转发,而是监听API server所有service中的定义转为本地的iptables规则缺点:iptables模式，一个service会生成大量的规则; 如果一个service有50条规则那如果有一万个容器,内核的性能就会受到影响

ipvs代理模式:

kube-ipvs0，将所有的ClusterlP绑定在该接口; 而后将每个Service定义为虚拟服务器; nat转发仅需要借助于极少量的iptables规则完成源地址转换等功能
ipvs代理模式: 在继承iptables优点的情况下,同时改进了iptables产生大量规则的缺点,在大规模集群中serice多的情况下优势更明显

示例2: 修改iptable为ipvs模式

[root@k8s-master ~]# kubectl get configmap -nkube-system NAMEDATAAGE coredns131d extension-apiserver-authentication631d kube-flannel-cfg231d kube-proxy231d kubeadm-config231d kubelet-config-1.19131d [root@k8s-master ~]# kubectl edit cm kube-proxy -n kube-system ... qps: 0 clusterCIDR: 10.244.0.0/16 configSyncPeriod: 0s conntrack: maxPerCore: null min: null tcpCloseWaitTimeout: null tcpEstablishedTimeout: null detectLocalMode: "" enableProfiling: false healthzBindAddress: "" hostnameOverride: "" iptables: masqueradeAll: false masqueradeBit: null minSyncPeriod: 0s syncPeriod: 0s ipvs: excludeCIDRs: null minSyncPeriod: 0s scheduler: ""#调度算法默认轮询算法 strictARP: false syncPeriod: 0s tcpFinTimeout: 0s tcpTimeout: 0s udpTimeout: 0s kind: KubeProxyConfiguration metricsBindAddress: "" mode: "ipvs"#默认为空修改来ipvs nodePortAddresses: null oomScoreAdj: null portRange: "" showHiddenMetricsForVersion: ""[root@k8s-master ~]# kubectl get pod -n kube-system -l k8s-app=kube-proxy NAMEREADYSTATUSRESTARTSAGE kube-proxy-4shl51/1Running631d kube-proxy-dw4tc1/1Running731d kube-proxy-xg2vf1/1Running631d [root@k8s-master ~]# kubectl deletepod -n kube-system -l k8s-app=kube-proxy#手动重启pod 生产环境最好是提前设定好 pod "kube-proxy-4shl5" deleted pod "kube-proxy-dw4tc" deleted pod "kube-proxy-xg2vf" deleted[root@k8s-master ~]# ifconfig kube-ipvs#修改成功好会有一个kube-ipvs的虚拟接口 kube-ipvs0: flags=130mtu 1500 inet 10.97.56.1netmask 255.255.255.255broadcast 0.0.0.0 ether b2:09:48:a5:8c:0atxqueuelen 0(Ethernet) RX packets 0bytes 0 (0.0 B) RX errors 0dropped 0overruns 0frame 0 TX packets 0bytes 0 (0.0 B) TX errors 0dropped 0 overruns 0carrier 0collisions 0[root@k8s-master ~]# kubectl get svc NAMETYPECLUSTER-IPEXTERNAL-IPPORT(S)AGE demoapp-externalip-svcClusterIP10.110.30.133192.168.100.10080/TCP42h demoapp-loadbalancer-svcLoadBalancer10.110.155.70【08.kubernetes笔记 Service(二) Endpoint Controller、修改iptable为ipvs模式】80:31619/TCP45h demoapp-nodeport-svcNodePort10.97.56.180:31399/TCP45h demoapp-svcClusterIP10.97.72.180/TCP47h http-externalClusterIP10.103.125.12880/TCP29h kubernetesClusterIP10.96.0.1443/TCP31d my-grafanaNodePort10.96.4.18580:30379/TCP29d myappNodePort10.106.116.20580:31532/TCP31droot@k8s-master ~]# ip addr show kube-ipvs0#所有svc的IP地址都可以在kube-ipvs0接口中找到也说明所有的svc都配置在kube-ipvs0接口上 14: kube-ipvs0: mtu 1500 qdisc noop state DOWN group default link/ether b2:09:48:a5:8c:0a brd ff:ff:ff:ff:ff:ff inet 10.97.56.1/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.110.30.133/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 192.168.100.100/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.97.72.1/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.103.125.128/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.96.4.185/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.96.0.10/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.110.155.70/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.106.116.205/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.108.171.56/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.106.239.211/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.103.145.83/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever inet 10.96.0.1/32 scope global kube-ipvs0 valid_lft forever preferred_lft forever[root@k8s-master ~]# ipvsadm -Ln#查看IPVS规格 IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:PortForward Weight ActiveConn InActConn TCP127.0.0.1:31619 rr -> 10.244.1.102:80Masq100 -> 10.244.1.103:80Masq100 -> 10.244.2.97:80Masq100 -> 10.244.2.99:80Masq100 TCP127.0.0.1:31994 rr -> 192.168.4.170:9100Masq100 -> 192.168.4.171:9100Masq100 -> 192.168.4.172:9100Masq100 TCP172.17.0.1:30169 rr -> 10.244.2.82:4443Masq100 TCP172.17.0.1:30379 rr -> 10.244.1.84:3000Masq100