K8S初级入门系列之八-网络
本章节介绍网络通讯的实现原理以及Service的相关核心概念,1、介绍了同一Pod内容器间,同一节点不同Pod,以及不同节点Pod的通讯原理和实现。2、Service,为同一组Pod提供统一的访问入口,通过Selector选择同组Pod,Service有四种类型,分别为ClusterIP,NodePort,LoadBalancer,ExternalNamed。Service是通过iptabels记
一、前言
本章节我们将了解K8S的相关网络概念,包括K8S的网络通讯原理,以及Service以及相关的概念,包括Endpoint,EndpointSlice,Headless service,Ingress等。
二、网络通讯原理和实现
同一K8S集群,网络通信实现可以简化为以下几个模型,Pod内容器之间的通信,同一节点内Pod间的通信,以及跨节点Pod的通信。
1、Pod内容器之间的通信
同一Pod内的容器是共享同一个网络命名空间的,它们就像工作在同一台机器上,可以使用localhost地址访问彼此的端口。其模型如下:
我们来看下面实例,其yaml文件如下
[root@k8s-master yaml]# cat network-pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: network-pod
spec:
containers:
- name: busybox
image: busybox
command:
- "/bin/sh"
- "-c"
- "sleep 3000"
- name: nginx
image: nginx:1.14.2
ports:
- containerPort: 80
该Pod包含两个容器(busybox和nginx),执行该文件,创建Pod,进入到 busybox容器,访问nginx容器。
[root@k8s-master yaml]# kubectl exec -it network-pod -c busybox sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
/ # curl
sh: curl: not found
/ # wget http://localhost
Connecting to localhost (127.0.0.1:80)
saving to 'index.html'
index.html 100% |******************************************************************************************************************************************| 612 0:00:00 ETA
'index.html' saved
/ # cat index.html
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
...
可以看到,在busybox容器中访问http://localhost,可以获取到ngnix的页面。
2、同一节点内Pod间的通信
其通信模型如下图所示:
同一节点Pod都关联到同一个网桥,地址段相同,从容器内发送的数据从eh0网络接口发出,再从veth接口出来,发送给网桥。网桥判断目标地址如果是同一个地址段,再由网桥发送给节点内部的对应Pod。
同样看个实例,我们将上面的Pod拆解为两个。
[root@k8s-master yaml]# cat network-busybox-pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: network-busybox-pod
spec:
containers:
- name: busybox
image: busybox
command:
- "/bin/sh"
- "-c"
- "sleep 3000"
[root@k8s-master yaml]# cat network-nginx-pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: network-nginx-pod
spec:
containers:
- name: nginx
image: nginx:1.14.2
ports:
- containerPort: 80
执行这两个文件,创建Pod后,进入busybox访问nginx(ip为10.244.36.80)。
[root@k8s-master yaml]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
network-busybox-pod 1/1 Running 0 20m 10.244.36.79 k8s-node1 <none> <none>
network-nginx-pod 1/1 Running 0 19m 10.244.36.80 k8s-node1 <none> <none>
[root@k8s-master yaml]# kubectl exec -it network-busybox-pod sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
/ # wget http://10.244.36.80
Connecting to 10.244.36.80 (10.244.36.80:80)
saving to 'index.html'
index.html 100% |*****************************************************************************************************************************************************************************************| 612 0:00:00 ETA
'index.html' saved
可以看到,在busybox容器中访问http://10.244.36.80,可以获取到ngnix的页面。
3、跨节点Pod间通信
其通信模型如下:
当一个报文从一个节点容器发送到另一个节点容器,报文先通过veth到网桥,再到节点物理适配器,通过网络传到其他节点的物理适配器,在通过其网桥,最终经过veth到达目标容器。这里需要有个前提:pod 的IP地址 必须是唯一的, 跨节点的网桥必须使用非重叠 地址段,这个需要通过IP地址规划保证。
上面的实例中,两个Pod都在k8s-node1节点上,我们将上面的busybox的Pod调度到master节点上。删除busybox的Pod,并改写下yaml内容。
[root@k8s-master yaml]# cat network-busybox-pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: network-busybox-pod
spec:
containers:
- name: busybox
image: busybox
command:
- "/bin/sh"
- "-c"
- "sleep 3000"
tolerations:
- key: "node-role.kubernetes.io/master"
operator: "Exists"
effect: "NoSchedule"
执行该文件,创建Pod,可以看到新Pod调度到Master上
[root@k8s-master yaml]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
network-busybox-pod 1/1 Running 0 20s 10.244.235.202 k8s-master <none> <none>
network-nginx-pod 1/1 Running 0 24m 10.244.36.80 k8s-node1 <none> <none>
进入该Pod,访问nginx
[root@k8s-master yaml]# kubectl exec -it network-busybox-pod sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
/ # wget http://10.244.36.80
Connecting to 10.244.36.80 (10.244.36.80:80)
saving to 'index.html'
index.html 100% |*****************************************************************************************************************************************************************************************| 612 0:00:00 ETA
'index.html' saved
可以看到,在busybox容器中访问http://10.244.36.80,可以获取到ngnix的页面。
三、Service
Service是K8S的核心概念之一,它是基于Pod上的业务网络层,为同一组Pod提供统一的访问入口,将请求负载转发到后端的Pod上,其作用类似于业务网关。
1、Service创建
在创建Service之前,我们先创建其后端应用,该应用使用镜像tcy83/k8s-service-app,镜像java代码如下:
@Controller
@RequestMapping("/k8s")
public class TestController {
private static Integer appId;
@GetMapping("getServiceApp")
@ResponseBody
public String getServiceApp(){
return "this this service app:"+generateAppId();
}
public static int generateAppId(){
if(appId == null){
Random random = new Random();
appId = random.nextInt(1000);
}
return appId;
}
}
解释下该段代码,当访问/k8s/getServiceApp,返回一段字符串,显示应用的appId,该appId在首次访问时随机分配,后续访问将保持不变,以便区别不同的应用实例。
接下来,就采用Deployment部署3个该应用的pod。其中yaml文件内容如下:
apiVersion: apps/v1
kind: Deployment
metadata:
name: serviceapp-deployment
labels:
app: serviceapp-deployment
spec:
replicas: 3
selector:
matchLabels:
app: serviceapp-deploy
template:
metadata:
labels:
app: serviceapp-deploy
spec:
containers:
- name: k8s-service-app
image: tcy83/k8s-service-app:0.1
ports:
- containerPort: 8080
创建完成后,我们看下pod运行情况:
[root@k8s-master yaml]# kubectl get pod -l app=serviceapp-deploy -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
serviceapp-deployment-649c69c89d-2k2hm 1/1 Running 0 90m 10.244.36.78 k8s-node1 <none> <none>
serviceapp-deployment-649c69c89d-h5s5g 1/1 Running 0 90m 10.244.36.119 k8s-node1 <none> <none>
serviceapp-deployment-649c69c89d-sjv55 1/1 Running 0 90m 10.244.36.123 k8s-node1 <none> <none>
根据pod的ip和port,能成功访问每一个应用。
[root@k8s-master ~]# curl http://10.244.36.78:8080/k8s/getServiceApp
this this service app:400
[root@k8s-master ~]# curl http://10.244.36.119:8080/k8s/getServiceApp
this this service app:204
[root@k8s-master ~]# curl http://10.244.36.123:8080/k8s/getServiceApp
this this service app:813
接下来就是重点部分,为这3个应用增加一个Service,作为统一访问入口。
[root@k8s-master yaml]# cat service-app-sv.yaml
apiVersion: v1
kind: Service
metadata:
name: service-app-service
spec:
type: ClusterIP
selector:
app: serviceapp-deploy
ports:
- port: 80
targetPort: 8080
其中的属性我们稍后再分析,先执行下service-app-sv.yaml
[root@k8s-master yaml]# kubectl apply -f service-app-sv.yaml
service/service-app-service created
[root@k8s-master yaml]# kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 133d
service-app-service ClusterIP 10.104.72.224 <none> 80/TCP 13s
Service正常运行,其集权内部访问IP为10.104.72.224,访问下该Service
[root@k8s-master yaml]# curl http://10.104.72.224:80/k8s/getServiceApp
this this service app:400
[root@k8s-master yaml]# curl http://10.104.72.224:80/k8s/getServiceApp
this this service app:204
[root@k8s-master yaml]# curl http://10.104.72.224:80/k8s/getServiceApp
this this service app:400
[root@k8s-master yaml]# curl http://10.104.72.224:80/k8s/getServiceApp
this this service app:400
[root@k8s-master yaml]# curl http://10.104.72.224:80/k8s/getServiceApp
this this service app:813
可以看到通过Service,能成功访问到后端的3个应用,且有负载均衡效果。我们再扩容一个新的Pod看看。
[root@k8s-master ~]# kubectl scale deployment/serviceapp-deployment --replicas=4
deployment.apps/serviceapp-deployment scaled
[root@k8s-master ~]# kubectl get pod -l app=serviceapp-deploy -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
serviceapp-deployment-649c69c89d-2k2hm 1/1 Running 0 12h 10.244.36.78 k8s-node1 <none> <none>
serviceapp-deployment-649c69c89d-h5s5g 1/1 Running 0 12h 10.244.36.119 k8s-node1 <none> <none>
serviceapp-deployment-649c69c89d-sjv55 1/1 Running 0 12h 10.244.36.123 k8s-node1 <none> <none>
serviceapp-deployment-649c69c89d-txlt9 1/1 Running 0 88s 10.244.36.103 k8s-master <none> <none>
再访问Service地址
[root@k8s-master ~]# curl http://10.104.72.224:80/k8s/getServiceApp
this this service app:303
[root@k8s-master ~]# curl http://10.104.72.224:80/k8s/getServiceApp
this this service app:813
[root@k8s-master ~]# curl http://10.104.72.224:80/k8s/getServiceApp
this this service app:400
[root@k8s-master ~]# curl http://10.104.72.224:80/k8s/getServiceApp
this this service app:204
[root@k8s-master ~]# curl http://10.104.72.224:80/k8s/getServiceApp
this this service app:400
可以看到新扩容的应用(appid=303),已经加入到集群,能通过Service访问到,示意图如下:
2、service原理分析
通过上面的实例,我们了解了Service的具备统一访问入口的功能,那么它是如何实现的呢?
(1)属性分析
我们分析下Service的主要属性:
- type,表示Service的类型,目前支持ClusterIP,NodePort,LoadBalancer,ExternalName四种,这四种类型的作用和用法,我们在后面具体分析。
- Selector,选择那些后端应用与该Service关联,上面的例子如图所示
通过selector属性,其值为Pod的label值,这样,所有标记为该label的Pod与该service关联起来。所以,通过Service的标签选择器实现与Pod的关联。
- ports,即Service访问port,以及后端应用的目标Port。
(2)Pod的访问
Service的IP实际上是VIP(虚拟IP),请求是如何转发到后端Pod的呢?其流程如下:
(1)Pod启动完成后,由kubelet将各Pod的ip注册到master节点。
(2)Service发布完成后,由Master分配ClusterIP,并与后端Pod的ip建立映射关系,存储到master节点。
(3)kube-proxy监听到变化后,修改本地的iptabels,写入clusterIp与Podip的映射关系。
(4)运行时,当Client访问Service的ClientIp时,由iptabels截获,根据映射关系以及负载均衡策略,转发到后端应用的Pod。
以上就是Service访问的iptabels的工作模式,也是默认的工作模式,该机制确保了Pod在扩缩容时,通过修改iptabels快速响应服务实例的变化;同时,由内核区的iptabels进行寻址和负载,也大大提升了效率。
在Pod实例扩容和缩容时,及时的体现到iptabel的映射表上。
3、Service类型
前面介绍了Service有四种类型,我们具体介绍下:
(1)ClusterIP
K8S为Service分配一个集群内部IP地址,该 IP只能在集群内部访问,这也是type的默认值。
前面创建的就是ClusterIP类型,其示意图如下:
除了前面讲的通过IP访问服务,service还默认分配一个域名,其格式 为<servicename>.<namespace>.svc.<clusterdomain>,上面例子service的域名:"service-app-service.default.svc.cluster.local",我们登录到集群中某个pod,再访问该域名的地址
[root@k8s-master yaml]# kubectl exec -it nginx-deployment-86644697c5-96q8l -- /bin/sh
# curl http://service-app-service.default.svc.cluster.local/k8s/getServiceApp
this this service app:400
可以看到通过Service域名能正确访问应用。
(2)NodePort
如果要对外提供服务(非集群内访问),ClusterIP模式是无法满足,此时需要采用NodePort,它是ClusterIP的扩展,在每个节点的开放一个本地静态端口(端口范围:30000-32767),该端口代理服务,通过节点上的端口可以访问服务。示意图如下:
下面我们改写下service-app-sv.yaml,将type修改为NodePort,并在ports中添加nodePort:30001
[root@k8s-master yaml]# cat service-app-sv.yaml
apiVersion: v1
kind: Service
metadata:
name: service-app-service
spec:
type: NodePort
selector:
app: serviceapp-deploy
ports:
- port: 80
targetPort: 8080
nodePort: 30001
创建Service后,查看运行状态
[root@k8s-master yaml]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 137d
service-app-service NodePort 10.110.47.22 <none> 80:30001/TCP 6m11s
此时我们就可以在公网上通过浏览器访问该服务
(3)LoadBalancer
公有云提供商一般提供负载均衡器向外部暴露服务,外部负载均衡器可以将流量路由到自动创建的NodePort服务和ClusterIP服务上。示意图如下:
创建一个yaml文件service-app-loadbalancer-sv.yaml
[root@k8s-master yaml]# cat service-app-loadbalancer-sv.yaml
apiVersion: v1
kind: Service
metadata:
name: service-app-service
spec:
type: LoadBalancer
selector:
app: serviceapp-deploy
ports:
- port: 80
targetPort: 8080
执行该文件,并查看Service运行状态
[root@k8s-master yaml]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 141d
service-app-service LoadBalancer 10.103.95.166 <pending> 80:32243/TCP 13m
已经自动分配了节点的32243端口,并映射到service的80端口,但是 EXTERNAL-IP一直处于pending状态,这是因为我没有购买共有用的负载均衡服务,购买后就会分配个负载均衡ip,实现loadbalancer。
(4)ExternalName
这种类型一般是我们在使用外集群的服务时,该服务暴露了DNS域名,就可以在本集群创建一个Service,并映射该域名,那么就可以在本集群访问该service,从而访问外集群的服务。示意图如下:
创建一个yaml文件,映射为百度的域名。
[root@k8s-master yaml]# cat service-app-externalname-sv.yaml
apiVersion: v1
kind: Service
metadata:
name: service-app-en-service
spec:
type: ExternalName
externalName: www.baidu.com
执行完成后,看下创建结果
[root@k8s-master yaml]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service-app-en-service ExternalName <none> www.baidu.com <none> 84m
当访问service-app-en-service.default.svc.cluster.local,集群DNS服务返回CNAME记录,其值为www.baidu.com。
为了验证下上面的结论,我们在集群中部署dns工具pod,镜像为dnsutils,其内容如下:
[root@k8s-master yaml]# cat dnsutils-pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: dnsutils
spec:
containers:
- name: dnsutils
image: mydlqclub/dnsutils:1.3
imagePullPolicy: IfNotPresent
command: ["sleep","3600"]
执行成功后,进入该pod内部,使用nslookup命令看下该域名的解析
[root@k8s-master yaml]# kubectl exec -it dnsutils /bin/sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
/ # nslookup service-app-en-service.default.svc.cluster.local
Server: 10.96.0.10
Address: 10.96.0.10#53
service-app-en-service.default.svc.cluster.local canonical name = www.baidu.com.
www.baidu.com canonical name = www.a.shifen.com.
Name: www.a.shifen.com
Address: 110.242.68.4
Name: www.a.shifen.com
Address: 110.242.68.3
再ping下百度的域名
[root@k8s-master yaml]# ping www.baidu.com
PING www.a.shifen.com (110.242.68.3) 56(84) bytes of data.
64 bytes from 110.242.68.3 (110.242.68.3): icmp_seq=1 ttl=52 time=4.47 ms
64 bytes from 110.242.68.3 (110.242.68.3): icmp_seq=2 ttl=52 time=4.45 ms
64 bytes from 110.242.68.3 (110.242.68.3): icmp_seq=3 ttl=52 time=4.37 ms
可以看到上面确实是返回了百度域名的ip。
三、EndPoint
在上面的Pod访问模块中,我们提到服务注册自己的ip到master节点,在实际的实现过程中,这些ip并不是一个物理列表,而之后由Endpoint管理,Service关联Endpoint。
我们先查下Endpoint列表
[root@k8s-master ~]# kubectl get endpoints
NAME ENDPOINTS AGE
kubernetes 192.168.16.4:6443 142d
service-app-service 10.244.36.103:8080,10.244.36.119:8080,10.244.36.123:8080 + 1 more... 25h
k8s集群中已经有了两个endpoint,其中一个是和service相同名称,其Endpoints就是pod的列表。这个Endpoint我们并没有显性的去创建,而是在创建Service时,k8s自动创建的。
那这种设计的好处是什么呢?其实就是为了解耦,Endpoint作为解耦层,可以灵活应对pod的变化,而Service不感知。
在一些实际工程中,部署在K8S集群的应用需要连接外部的数据库,或者另一个集群或者Namespace的服务作为服务的后端,这种场景下就需要用到Endpoint。
下面我们来看一个Endpoint的使用实例,如图所示:
集群外部部署了一个mongdb数据库,集群内部应用A需要连接该数据库,由于集群导致的网络隔离,无法直接访问。此时就是可以使用Service+手动配置Endpoint实现。
其yaml内容如下:
[root@k8s-master yaml]# cat mongodb_service.yaml
apiVersion: v1
kind: Service
metadata:
name: mongodb-svc
spec:
ports:
- port: 27017
targetPort: 27017
protocol: TCP
---
kind: Endpoints
apiVersion: v1
metadata:
name: mongodb-svc
subsets:
- addresses:
# 外部 mongodb IP
- ip: 192.168.16.4
ports:
# mongodb 端口
- port: 27017
首先我们创建了一个名为 mongodb-svc的service,需要注意,该service没有selector选择器,也可以认为该service没有挂载后端服务,其他的和上面的service没有区别。
接着又创建一个Endpoints,其名称要为service一致(这里非常关键,service与endpoints关联关系依赖name相同),在subsets中,我们配置mongodb的ip(也可以是域名,这里仅配置master库)和端口。
集群中的应用A就 可以通过访问该服务的域名来访问mongodb数据库了,配置如下
spring:
data:
mongodb:
uri: mongodb://ai_admin:123456@mongodb-svc:27017/ai
四、Endpointslice
在大型集群中,endpoint存在诸多限制
- Pod数据限制,一个服务对应一个Endpoint资源,这意味着它需要为支持相应服务的每个Pod存储IP地址和端口(网络端点),Endpoint需要存储大量的ip和端口信息,而存储在etcd中的对象的默认大小限制为1.5MB,也就是最多能存储5000个pod的ip,在大多数情况下,是满足工程要求。但是在一些大型集群中,数量超过这个限制,就存在问题。
- 更新代价大,kube-proxy 会在每个节点上运行,并监控 Endpoint 资源的任何更新,如果 Endpoint 资源中有一个端口发生更改,那么整个对象都会分发到 kube-proxy 的每个实例。如果service有5000个pod,在3000个节点情况下,每次更新将会跨节点发送 4.5GB 的数据(1.5M*3000)。再想象下,如果5000个pod都滚动更新一次,全部被替换,那么传输的数据量将超过22TB,这个是恐怖的数据。
为了解决以上的Endpoint存在的限制,在是 Kubernetes 1.18 中引入的一个新的 API 对象EndpointSlice,通过分片管理一组Endpoint,这样将数据量以及更新的范围限制在一个分片内,来解决以上两个问题。
EndPointSlice根据Endpoint所在Node的拓扑信息进行分片管理,分为Node,Zone,Region三个级别,如下图所示。
接下来我们看下K8s的EndpointSlice列表
[root@k8s-master ~]# kubectl get endpointslice
NAME ADDRESSTYPE PORTS ENDPOINTS AGE
service-app-service-bf5vr IPv4 8080 10.244.36.78,10.244.36.103,10.244.36.123 + 1 more... 5d18h
创建了以Endpoint名称为前缀的EndpointSlice。再来看下EndpointSlice的详情。
[root@k8s-master ~]# kubectl describe endpointslice service-app-service-bf5vr
Name: service-app-service-bf5vr
Namespace: default
Labels: endpointslice.kubernetes.io/managed-by=endpointslice-controller.k8s.io
kubernetes.io/service-name=service-app-service
Annotations: endpoints.kubernetes.io/last-change-trigger-time: 2023-03-26T10:29:05Z
AddressType: IPv4
Ports:
Name Port Protocol
---- ---- --------
<unset> 8080 TCP
Endpoints:
- Addresses: 10.244.36.78
Conditions:
Ready: true
Hostname: <unset>
TargetRef: Pod/serviceapp-deployment-649c69c89d-2k2hm
NodeName: k8s-node1
Zone: <unset>
- Addresses: 10.244.36.103
Conditions:
Ready: true
Hostname: <unset>
TargetRef: Pod/serviceapp-deployment-649c69c89d-txlt9
NodeName: k8s-node1
Zone: <unset>
- Addresses: 10.244.36.123
Conditions:
Ready: true
Hostname: <unset>
TargetRef: Pod/serviceapp-deployment-649c69c89d-sjv55
NodeName: k8s-node1
Zone: <unset>
- Addresses: 10.244.36.119
Conditions:
Ready: true
Hostname: <unset>
TargetRef: Pod/serviceapp-deployment-649c69c89d-h5s5g
NodeName: k8s-node1
Zone: <unset>
Events: <none>
我们来看下重要的属性参数
- Labels的kubernetes.io/service-name,表示关联的service名称。
- AddressType,包括三种取值,IPv4,IPv6,FQDN(全限定域名)
- Endpoints,列出的每个Endpoint的信息,其中包括:
Addresses:Endpoint的IP地址;
Conditions:Endpoint状态信息,作为EndpointSlice的查询条件;
Hostname:在Endpoint中设置的主机名nostname;
TargetRef:Endpoint对应的Pod名称;
NodeName:所在的节点名
Zone,所在的zone区
Topology:拓扑信息,为基于拓扑感知的服务路由提供数据。(需要设置服务拓扑key)
总之,在大规模集群下,EndpointSlice通过对Endpoint进行分片管理来实现降低Master和各Node之间的网络传输数据量及提高整体性能的目标。同时还支持围绕双栈网络和拓扑感知路由等新功能的创新。
五、Headless Service
在某些应用场景中,我们仅希望Service实现服务发现,即后端服务有改变,能反映在端点列表,但是不希望使用Service的服务路由功能,即由业务获取列表后,自定义服务的负载均衡策略,决定需要连接具体哪个服务,此时,就可以使用Headless Service。一般应用在有状态服务中(在后续的Stateful控制器会介绍有状态服务类型)。
比如,有一组根据userId字段进行分片的MySql分库,当应用A读写用户信息时,根据userId的分片策略,决定路由到哪个分库。如下图所示:
下面我们将前面的service-app-sv.yaml改造成Headless Service,其yaml内如如下:
[root@k8s-master yaml]# cat service-app-headless-sv.yaml
apiVersion: v1
kind: Service
metadata:
name: service-app-headless-service
spec:
# clusterIp为None即为headless service
clusterIP: None
selector:
app: serviceapp-deploy
ports:
- port: 80
targetPort: 8080
该yaml中clusterIP:None即表示Headless Service。用前面创建的四个Pod模拟分库。执行完成后,我们看下服务列表
[root@k8s-master yaml]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service-app-headless-service ClusterIP None <none> 80/TCP 7m11s
可以看到其cluster ip为None,也就是该Service无法通过ip访问。前面我们介绍过每个Service都有一个默认域名,Headless Service也不例外,该Service的域名为service-app-headless-service.default.svc.cluster.local,通过nslookup指令模拟应用A客户端获取Endpoint列表。
[root@k8s-master yaml]# kubectl exec -it dnsutils /bin/sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
/ # nslookup service-app-headless-service.default.svc.cluster.local
Server: 10.96.0.10
Address: 10.96.0.10#53
Name: service-app-headless-service.default.svc.cluster.local
Address: 10.244.36.119
Name: service-app-headless-service.default.svc.cluster.local
Address: 10.244.36.78
Name: service-app-headless-service.default.svc.cluster.local
Address: 10.244.36.103
Name: service-app-headless-service.default.svc.cluster.local
Address: 10.244.36.123
可以看到,应用A能正确获取后端应用IP列表,后续可以自行决策如何负载,连接哪个数据库分库。
六、Ingress
前面介绍的Service都是基于IP:Port模式,即工作在四层TCP协议层。在工程实践中,我们应用更多的是需要工作在七层Http/Https层的网关服务,此时Service对象是无法满足。从1.1版本开始,K8S提供Ingress对象,通过配置转发策略,将不同的URL请求转发到后端不同的Service上,实现基于HTTP的路由机制。
其示意图如下:
Ingress需要配合Ingress控制器一起使用。Ingress主要用来配置规则,简单理解,就是Ngnix上配置的转发规则,抽象成Ingress对象,使用yaml文件创建,更改时,仅更新yaml文件即可。而Ingress Controller是真正实现负载均衡能力,它感知集群中Ingress规则变化,然后读取他,按照他自己模板生成一段 Nginx 配置,再写到 Nginx Pod 里。
简单来讲,Ingress是负责解决怎么处理的问题,Ingress Controller根据处理的策略,实现处理方式。
1、Ingress的配置规则
Ingress支持以下几种配置规则
(1)、转发到单个后端服务
这种比较简单,对于Ingress Controller IP的访问都会转发到该后端服务上,如下:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: nginx
spec:
backend:
serviceName: nginx
servicePort: 8080
2、同一域名下,不同URL路径被转发到不同的服务上
yaml内容如下,在访问k8s.nginx.cn域名,根据后面的path,决定路由到对应的服务。
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: nginx
spec:
rules:
- host: k8s.nginx.cn
http:
paths:
- path: /image
pathType: Prefix
backend:
service:
name: image
port:
number: 80
- path: /app
pathType: Prefix
backend:
service:
name: webapp
port:
number: 80
3、不同域名,被转发到不同的服务上
yaml内容如下,根据域名不同,转发不同的后端Service。
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: nginx
spec:
rules:
- host: k8s.image.cn
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: image
port:
number: 80
- host: k8s.nginx.cn
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: nginx
port:
number: 80
4、不使用域名转发
这个实际是第一个的变种,其yaml文件如下:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: nginx
spec:
rules:
http:
paths:
- path: /nginx
backend:
serviceName: nginx
servicePort: 8080
当访问ingress controller ip/nginx路径时,转发到后端的nginx服务上。
2、案例实践
通过案例实践,看下如何实现Ingres的配置转发功能。
(1)创建Ingress controller
首先我们创建Ingress Controller, K8S目前支持AWS,GCE和Nginx控制器,我们这里使用K8s提供的Ngnix Controller 1.3.1版本
下载yaml文件后,修改其中的controller镜像地址(原有的镜像地址国内无法访问),以及增加 hostNetwork: true(打通Cluster和node的网络),demo-1.3.1.yaml文件内容参见附件。
[root@k8s-master yaml]# kubectl apply -f demo-1.3.1.yaml
namespace/ingress-nginx created
serviceaccount/ingress-nginx created
serviceaccount/ingress-nginx-admission created
role.rbac.authorization.k8s.io/ingress-nginx created
role.rbac.authorization.k8s.io/ingress-nginx-admission created
clusterrole.rbac.authorization.k8s.io/ingress-nginx unchanged
clusterrole.rbac.authorization.k8s.io/ingress-nginx-admission unchanged
rolebinding.rbac.authorization.k8s.io/ingress-nginx created
rolebinding.rbac.authorization.k8s.io/ingress-nginx-admission created
clusterrolebinding.rbac.authorization.k8s.io/ingress-nginx unchanged
clusterrolebinding.rbac.authorization.k8s.io/ingress-nginx-admission unchanged
configmap/ingress-nginx-controller created
service/ingress-nginx-controller created
service/ingress-nginx-controller-admission created
deployment.apps/ingress-nginx-controller created
job.batch/ingress-nginx-admission-create created
job.batch/ingress-nginx-admission-patch created
ingressclass.networking.k8s.io/nginx unchanged
validatingwebhookconfiguration.admissionregistration.k8s.io/ingress-nginx-admission configured
执行该文件成功后,可以看到在命名空间ingress-nginx下创建了一系列的对象。
[root@k8s-master yaml]# kubectl get pod,svc,ing,deploy -n ingress-nginx
NAME READY STATUS RESTARTS AGE
pod/ingress-nginx-admission-create-6sbrv 0/1 Completed 0 3m12s
pod/ingress-nginx-admission-patch-dghkc 0/1 Completed 1 3m12s
pod/ingress-nginx-controller-7dd587ccd5-8xr8j 1/1 Running 0 3m12s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/ingress-nginx-controller LoadBalancer 10.96.244.230 <pending> 80:32148/TCP,443:31937/TCP 3m12s
service/ingress-nginx-controller-admission ClusterIP 10.107.184.217 <none> 443/TCP 3m12s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/ingress-nginx-controller 1/1 1 1 3m12s
其中Ingress Controller实际是一个Pod实现的,这里就是 pod/ingress-nginx-controller-7dd587ccd5-8xr8j。
(2)创建Deployment
接着我们创建后端应用Pod,通过Nginx的镜像来模拟。
创建 命名空间为ns-ingress-test的NameSpace,并创建所属该命名空间的Deployment,yaml内容如下:
[root@k8s-master yaml]# cat ingress-pod.yaml
apiVersion: v1
kind: Namespace
metadata:
name: ns-ingress-test
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
namespace: ns-ingress-test
labels:
app: ingress-nginx
spec:
selector:
matchLabels:
app: ingress-nginx
replicas: 2
template:
metadata:
labels:
app: ingress-nginx
spec:
containers:
- name: nginx
image: nginx:1.14.2
ports:
- containerPort: 80
执行该文件后,查看pod的运行状态,完成了2个Pod的运行。
[root@k8s-master yaml]# kubectl get pods -n ns-ingress-test
NAME READY STATUS RESTARTS AGE
nginx-7d8856bf4f-cxnx8 1/1 Running 0 5m1s
nginx-7d8856bf4f-hhk7x 1/1 Running 0 5m1s
(3)创建Service
接下来创建访问该应用Pod的Service对象,type为ClusterIP,内容如下:
[root@k8s-master yaml]# cat ingress-sv.yaml
apiVersion: v1
kind: Service
metadata:
name: nginx
namespace: ns-ingress-test
spec:
ports:
- port: 80
targetPort: 80
selector:
app: ingress-nginx
type: ClusterIP
执行完成后,检查Service状态
[root@k8s-master yaml]# kubectl get svc -n ns-ingress-test
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
nginx ClusterIP 10.106.13.73 <none> 80/TCP 20s
到此为止,我们通过Service的IP就可以访问下nginx了。
[root@k8s-master yaml]# curl 10.106.13.73:80
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
....
可以看到访问正常,说明Nginx应用运行正常。
(4)创建Ingress
这也是关键一步,通过Ingress配置访问策略,其yaml文件内容如下
[root@k8s-master yaml]# cat ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: nginx
namespace: ns-ingress-test
annotations:
kubernetes.io/ingress.class: "nginx" # 指定 Ingress Controller 的类型
spec:
ingressClassName: nginx
rules:
- host: k8s.nginx.cn
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: nginx
port:
number: 80
这里较简单,通过域名k8s.nginx.cn,访问后端Service,并指定ingressClassName为Ingress controller的名称。执行完成后,看下Ingress的状态。
[root@k8s-master yaml]# kubectl get ingress -A
NAMESPACE NAME CLASS HOSTS ADDRESS PORTS AGE
ns-ingress-test nginx nginx k8s.nginx.cn 80 20m
(5)检测
到此为止,我们就可以通过域名在外网访问服务了。在客户端windows的hosts文件中增加域名映射
xx.xx.xx.xx k8s.nginx.cn
xx.xx.xx.xx为所在节点的公网IP,配置完成后可以通过浏览器访问
七、总结
本章节介绍网络通讯的实现原理以及Service的相关核心概念,
1、介绍了同一Pod内容器间,同一节点不同Pod,以及不同节点Pod的通讯原理和实现。
2、Service,为同一组Pod提供统一的访问入口,通过Selector选择同组Pod,Service有四种类型,分别为ClusterIP,NodePort,LoadBalancer,ExternalNamed。Service是通过iptabels记录虚拟IP与后端Pod IP的关系,并实现流量的四层转发和负载。
3、Endpoint,Endpoint是管理后端应用的IP列表,通过Endpoint实现Service与后端应用的解耦。通过Service+手动配置Endpoint,实现对集群外应用的访问。
4、Endpointslice,在大规模集群中,Endpoint存在性能上的限制,Endpointslice通过分片管理,降低Master和各Node之间的网络传输数据量及提高整体性能。
5、Headless Service,是Service的一个变种,采用ClusterIP:None标记,一般应用于仅需要使用Service服务发现,不需要服务路由的场景中。
6、Ingress,Ingress可以实现七层路由的转发,Ingress负责规则的配置,而真正的流量转发则是由Ingress Controller实现。
附:
K8S初级入门系列之四-Namespace/ConfigMap/Secret
K8S初级入门系列之六-控制器(RC/RS/Deployment)
K8S初级入门系列之七-控制器(Job/CronJob/Daemonset)
附件
demo-1.3.1.yaml文件内容
apiVersion: v1
kind: Namespace
metadata:
labels:
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
name: ingress-nginx
---
apiVersion: v1
automountServiceAccountToken: true
kind: ServiceAccount
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx
namespace: ingress-nginx
---
apiVersion: v1
kind: ServiceAccount
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-admission
namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx
namespace: ingress-nginx
rules:
- apiGroups:
- ""
resources:
- namespaces
verbs:
- get
- apiGroups:
- ""
resources:
- configmaps
- pods
- secrets
- endpoints
verbs:
- get
- list
- watch
- apiGroups:
- ""
resources:
- services
verbs:
- get
- list
- watch
- apiGroups:
- networking.k8s.io
resources:
- ingresses
verbs:
- get
- list
- watch
- apiGroups:
- networking.k8s.io
resources:
- ingresses/status
verbs:
- update
- apiGroups:
- networking.k8s.io
resources:
- ingressclasses
verbs:
- get
- list
- watch
- apiGroups:
- ""
resourceNames:
- ingress-controller-leader
resources:
- configmaps
verbs:
- get
- update
- apiGroups:
- ""
resources:
- configmaps
verbs:
- create
- apiGroups:
- coordination.k8s.io
resourceNames:
- ingress-controller-leader
resources:
- leases
verbs:
- get
- update
- apiGroups:
- coordination.k8s.io
resources:
- leases
verbs:
- create
- apiGroups:
- ""
resources:
- events
verbs:
- create
- patch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-admission
namespace: ingress-nginx
rules:
- apiGroups:
- ""
resources:
- secrets
verbs:
- get
- create
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
labels:
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx
rules:
- apiGroups:
- ""
resources:
- configmaps
- endpoints
- nodes
- pods
- secrets
- namespaces
verbs:
- list
- watch
- apiGroups:
- coordination.k8s.io
resources:
- leases
verbs:
- list
- watch
- apiGroups:
- ""
resources:
- nodes
verbs:
- get
- apiGroups:
- ""
resources:
- services
verbs:
- get
- list
- watch
- apiGroups:
- networking.k8s.io
resources:
- ingresses
verbs:
- get
- list
- watch
- apiGroups:
- ""
resources:
- events
verbs:
- create
- patch
- apiGroups:
- networking.k8s.io
resources:
- ingresses/status
verbs:
- update
- apiGroups:
- networking.k8s.io
resources:
- ingressclasses
verbs:
- get
- list
- watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-admission
rules:
- apiGroups:
- admissionregistration.k8s.io
resources:
- validatingwebhookconfigurations
verbs:
- get
- update
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx
namespace: ingress-nginx
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: ingress-nginx
subjects:
- kind: ServiceAccount
name: ingress-nginx
namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-admission
namespace: ingress-nginx
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: ingress-nginx-admission
subjects:
- kind: ServiceAccount
name: ingress-nginx-admission
namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
labels:
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: ingress-nginx
subjects:
- kind: ServiceAccount
name: ingress-nginx
namespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-admission
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: ingress-nginx-admission
subjects:
- kind: ServiceAccount
name: ingress-nginx-admission
namespace: ingress-nginx
---
apiVersion: v1
data:
allow-snippet-annotations: "true"
kind: ConfigMap
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-controller
namespace: ingress-nginx
---
apiVersion: v1
kind: Service
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-controller
namespace: ingress-nginx
spec:
externalTrafficPolicy: Local
ipFamilies:
- IPv4
ipFamilyPolicy: SingleStack
ports:
- appProtocol: http
name: http
port: 80
protocol: TCP
targetPort: http
- appProtocol: https
name: https
port: 443
protocol: TCP
targetPort: https
selector:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
type: LoadBalancer
---
apiVersion: v1
kind: Service
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-controller-admission
namespace: ingress-nginx
spec:
ports:
- appProtocol: https
name: https-webhook
port: 443
targetPort: webhook
selector:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
type: ClusterIP
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-controller
namespace: ingress-nginx
spec:
minReadySeconds: 0
revisionHistoryLimit: 10
selector:
matchLabels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
template:
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
spec:
hostNetwork: true
containers:
- args:
- /nginx-ingress-controller
- --publish-service=$(POD_NAMESPACE)/ingress-nginx-controller
- --election-id=ingress-controller-leader
- --controller-class=k8s.io/ingress-nginx
- --ingress-class=nginx
- --configmap=$(POD_NAMESPACE)/ingress-nginx-controller
- --validating-webhook=:8443
- --validating-webhook-certificate=/usr/local/certificates/cert
- --validating-webhook-key=/usr/local/certificates/key
env:
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
- name: LD_PRELOAD
value: /usr/local/lib/libmimalloc.so
image: registry.cn-hangzhou.aliyuncs.com/google_containers/nginx-ingress-controller:v1.3.1
imagePullPolicy: IfNotPresent
lifecycle:
preStop:
exec:
command:
- /wait-shutdown
livenessProbe:
failureThreshold: 5
httpGet:
path: /healthz
port: 10254
scheme: HTTP
initialDelaySeconds: 10
periodSeconds: 10
successThreshold: 1
timeoutSeconds: 1
name: controller
ports:
- containerPort: 80
name: http
protocol: TCP
- containerPort: 443
name: https
protocol: TCP
- containerPort: 8443
name: webhook
protocol: TCP
readinessProbe:
failureThreshold: 3
httpGet:
path: /healthz
port: 10254
scheme: HTTP
initialDelaySeconds: 10
periodSeconds: 10
successThreshold: 1
timeoutSeconds: 1
resources:
requests:
cpu: 100m
memory: 90Mi
securityContext:
allowPrivilegeEscalation: true
capabilities:
add:
- NET_BIND_SERVICE
drop:
- ALL
runAsUser: 101
volumeMounts:
- mountPath: /usr/local/certificates/
name: webhook-cert
readOnly: true
dnsPolicy: ClusterFirst
nodeSelector:
kubernetes.io/os: linux
serviceAccountName: ingress-nginx
terminationGracePeriodSeconds: 300
volumes:
- name: webhook-cert
secret:
secretName: ingress-nginx-admission
---
apiVersion: batch/v1
kind: Job
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-admission-create
namespace: ingress-nginx
spec:
template:
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-admission-create
spec:
hostNetwork: true
containers:
- args:
- create
- --host=ingress-nginx-controller-admission,ingress-nginx-controller-admission.$(POD_NAMESPACE).svc
- --namespace=$(POD_NAMESPACE)
- --secret-name=ingress-nginx-admission
env:
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
image: registry.cn-hangzhou.aliyuncs.com/google_containers/kube-webhook-certgen:v1.3.0
imagePullPolicy: IfNotPresent
name: create
securityContext:
allowPrivilegeEscalation: false
nodeSelector:
kubernetes.io/os: linux
restartPolicy: OnFailure
securityContext:
fsGroup: 2000
runAsNonRoot: true
runAsUser: 2000
serviceAccountName: ingress-nginx-admission
---
apiVersion: batch/v1
kind: Job
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-admission-patch
namespace: ingress-nginx
spec:
template:
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-admission-patch
spec:
hostNetwork: true
containers:
- args:
- patch
- --webhook-name=ingress-nginx-admission
- --namespace=$(POD_NAMESPACE)
- --patch-mutating=false
- --secret-name=ingress-nginx-admission
- --patch-failure-policy=Fail
env:
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
image: registry.cn-hangzhou.aliyuncs.com/google_containers/kube-webhook-certgen:v1.3.0
imagePullPolicy: IfNotPresent
name: patch
securityContext:
allowPrivilegeEscalation: false
nodeSelector:
kubernetes.io/os: linux
restartPolicy: OnFailure
securityContext:
fsGroup: 2000
runAsNonRoot: true
runAsUser: 2000
serviceAccountName: ingress-nginx-admission
---
apiVersion: networking.k8s.io/v1
kind: IngressClass
metadata:
labels:
app.kubernetes.io/component: controller
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: nginx
spec:
controller: k8s.io/ingress-nginx
---
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
metadata:
labels:
app.kubernetes.io/component: admission-webhook
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
app.kubernetes.io/version: 1.3.1
name: ingress-nginx-admission
webhooks:
- admissionReviewVersions:
- v1
clientConfig:
service:
name: ingress-nginx-controller-admission
namespace: ingress-nginx
path: /networking/v1/ingresses
failurePolicy: Fail
matchPolicy: Equivalent
name: validate.nginx.ingress.kubernetes.io
rules:
- apiGroups:
- networking.k8s.io
apiVersions:
- v1
operations:
- CREATE
- UPDATE
resources:
- ingresses
sideEffects: None
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