kubernetes系列教程(十八)TKE中实现ingress服务暴露
上一篇文章中介绍了基于Nginx实现Ingress Controller的实现，介绍了Nginx Ingress Controller安装、相关功能，TLS，高级特性等介绍，本章开始介绍基于腾讯云TKE实现ingress服务暴露。
1. TKE ingress
1.1 TKE ingress架构
TKE是Tencent Kubernetes Engine即腾讯云基于kubernetes提供的公有云上容器云服务，TKE提供了两种暴露服务的方式：service和ingress。
- 内网CLB，四层负载均衡，提供VPC内访问，通过node节点的NodePort转发至service；
- 外网CLB，四层负载均衡，提供公网访问，需要node节点具有访问公网的能力；
- ingress， 七层负载均衡，提供http和https接入，提供ingress控制器的功能，借助NodePort转发
要使用TKE的ingress功能，需要了解一下相关的组件内容：
- l7-lb-controller ingress客户端，安装在kube-system，用于解析ingress配置并更新CLB的规则
- CLB 七层负载均衡，提供ingress controller的功能，根据ingress规则创建http/https监听器，配置转发规则，以NodePort端口绑定后端RS
- Service 用于ingress服务发现，通过NodePort方式接入CLB
- 证书 用于提供https接入，配置在CLB负载均衡上，提供CA签名证书，通过Secrets封装给CLB使用
由于nginx ingress controller是直接以Pod的形势部署在kubernetes集群中，借助于service的服务发现可直接实现和pod通讯，而TKE中ingress controller未直接部署在k8s集群中，网络的接入需借助于service的NodePort实现接入，其数据流如下图：
1.2 ingress虚拟主机
环境说明: 创建两个Deployment并以NodePort方式暴露服务，www1.happylau.cn对应tke-app-1服务，同理www2.happylau.cn对应tke-app-2服务，如下演示操作过程：
1、创建两个Deployments
[_10_2_centos ingress]# kubectl create deployment tke-app-1 --image=nginx:1.7.9 [_10_2_centos ingress]# kubectl create deployment tke-app-2 --image=nginx:1.7.9
2、 将两个Deployment以NodePort的方式暴露服务
[_10_2_centos ~]# kubectl expose deployment tke-app-1 --port=80 --type=NodePort [_10_2_centos ~]# kubectl expose deployment tke-app-2 --port=80 --type=NodePort 查看服务列表 [_10_2_centos ~]# kubectl get services NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 172.16.255.1 <none> 443/TCP 83d tke-app-1 NodePort 172.16.255.91 <none> 80:30597/TCP 2s tke-app-2 NodePort 172.16.255.236 <none> 80:31674/TCP 73s
3、定义ingress规则，定义两个host将不同主机转发至backend不同的service
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: tke-ingress-demo
annotations:
kubernetes.io/ingress.class: qcloud
spec:
rules:
- host: www1.happylau.cn
http:
paths:
- path: /
backend:
serviceName: tke-app-1
servicePort: 80
- host: www2.happylau.cn
http:
paths:
- path: /
backend:
serviceName: tke-app-2
servicePort: 804、 应用ingress规则，并查看ingress详情，可以看到ingress创建了一个公网CLB实例
#应用ingress规则
[_10_2_centos ingress]# kubectl apply -f tke-ingress-demo.yaml
ingress.extensions/tke-ingress-demo created
#查看ingress列表
[_10_2_centos ingress]# kubectl get ingresses
NAME HOSTS ADDRESS PORTS AGE
tke-ingress-demo www1.happylau.cn,www2.happylau.cn 140.143.84.xxx 80 67s
#查看 ingress详情
[_10_2_centos ingress]# kubectl describe ingresses tke-ingress-demo
Name: tke-ingress-demo
Namespace: default
Address: 140.143.84.xxx
Default backend: default-http-backend:80 (<none>)
Rules:
Host Path Backends
---- ---- --------
www1.happylau.cn
/ tke-app-1:80 (172.16.1.15:80)
www2.happylau.cn
/ tke-app-2:80 (172.16.2.17:80)
Annotations:
kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"extensions/v1beta1","kind":"Ingress","metadata":{"annotations":{"kubernetes.io/ingress.class":"qcloud"},"name":"tke-ingress-demo","namespace":"default"},"spec":{"rules":[{"host":"www1.happylau.cn","http":{"paths":[{"backend":{"serviceName":"tke-app-1","servicePort":80},"path":"/"}]}},{"host":"www2.happylau.cn","http":{"paths":[{"backend":{"serviceName":"tke-app-2","servicePort":80},"path":"/"}]}}]}}
kubernetes.io/ingress.class: qcloud
kubernetes.io/ingress.qcloud-loadbalance-id: lb-a0xwhcx3
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal EnsuringIngress 69s (x3 over 89s) loadbalancer-controller Ensuring ingress
Normal CREATE 69s (x2 over 70s) loadbalancer-controller create loadbalancer succ
Normal EnsuredIngress 68s (x3 over 70s) loadbalancer-controller Ensured ingress5、测试验证，将IP和域名写入到hosts文件中，访问域名测试验证，如下通过curl解析的方式测试验证
6、ingress会创建一个CLB，并在CLB中创建监听器、设置转发规则、绑定后端RS，下图是CLB上自动生成的规则
通过上面演示可知：
- 自动创建CLB实例
- CLB实例上配置监听器
- 配置转发规则
- 绑定Node节点
- 绑定端口为service创建的NodePort
1.3 ingress证书加密
TKE支持将在CLB中加载证书实现https加密传输，证书是经过第三方认证的CA签名过的证书，需要先购买好证书，通过Secrets对象在kubernetes集群中定义，如下演示https的实现。
1、 通过Secrets创建证书，先获取到证书的id，如果没有则先创建证书，证书管理，本文以证书id TKPmsWb3 为例，通过stringData能实现base64自动加密
apiVersion: v1
kind: Secret
metadata:
name: ingress-ssl-key
stringData:
qcloud_cert_id: TKPmsWb3
type: Opaque
#生成Secrets对象
[_10_2_centos ingress]# kubectl apply -f ingress-secret.yaml
secret/ingress-ssl-key created
[_10_2_centos ingress]# kubectl get secrets ingress-ssl-key
NAME TYPE DATA AGE
ingress-ssl-key Opaque 1 7s
#查看secrets详情，可得知VEtQbXNXYjM= 已自动通过base64加密
[_10_2_centos ingress]# kubectl get secrets ingress-ssl-key -o yaml
apiVersion: v1
data:
qcloud_cert_id: VEtQbXNXYjM=
kind: Secret
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"v1","kind":"Secret","metadata":{"annotations":{},"name":"ingress-ssl-key","namespace":"default"},"stringData":{"qcloud_cert_id":"TKPmsWb3"},"type":"Opaque"}
creationTimestamp: "2020-01-03T11:53:33Z"
name: ingress-ssl-key
namespace: default
resourceVersion: "7083702418"
selfLink: /api/v1/namespaces/default/secrets/ingress-ssl-key
uid: aaea4a86-2e1f-11ea-a618-ae9224ffad1a
type: Opaque
#可以通过base64查看解密后的内容，和配置文件中定义的id一致
[_10_2_centos ingress]# echo VEtQbXNXYjM= | base64 -d
TKPmsWb32、准备环境，创建一个nginx的Deployment
[_10_2_centos ~]# kubectl create deployment tke-ingress-ssl-demo --image=nginx:1.7.9 deployment.apps/tke-ingress-ssl-demo created [_10_2_centos ~]# kubectl get deployments NAME READY UP-TO-DATE AVAILABLE AGE tke-ingress-ssl-demo 1/1 1 1 6s
3、将Deployment暴露以NodePort类型暴露service
[_10_2_centos ~]# kubectl expose deployment tke-ingress-ssl-demo --port=80 --type=NodePort
service/tke-ingress-ssl-demo exposed
[_10_2_centos ~]# kubectl get service tke-ingress-ssl-demo -o yaml
apiVersion: v1
kind: Service
metadata:
creationTimestamp: "2020-01-03T12:00:05Z"
labels:
app: tke-ingress-ssl-demo
name: tke-ingress-ssl-demo
namespace: default
resourceVersion: "7083890283"
selfLink: /api/v1/namespaces/default/services/tke-ingress-ssl-demo
uid: 94659f42-2e20-11ea-a618-ae9224ffad1a
spec:
clusterIP: 172.16.255.64
externalTrafficPolicy: Cluster
ports:
- nodePort: 30324
port: 80
protocol: TCP
targetPort: 80
selector:
app: tke-ingress-ssl-demo
sessionAffinity: None
type: NodePort #类型为NodePort
status:
loadBalancer: {}4、定义ingress规则，加载证书实现https转发
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: tke-ingress-ssl
annotations:
kubernetes.io/ingress.class: qcloud
qcloud_cert_id: TKPmsWb3
spec:
rules:
- host: www.happylauliu.cn
http:
paths:
- path: /
backend:
serviceName: tke-ingress-ssl-demo
servicePort: 80
tls:
- hosts:
- www.happylauliu.cn
secretName: ingress-ssl-key5、应用ingress规则，并查看详情，此时已正常创建CLB并配置规则
[_10_2_centos ingress]# kubectl apply -f ingress-demo.yaml
ingress.extensions/tke-ingress-ssl created
#查看ingress详情
[_10_2_centos ingress]# kubectl describe ingresses tke-ingress-ssl
Name: tke-ingress-ssl
Namespace: default
Address: 140.143.83.xxx #CLB的外网IP
Default backend: default-http-backend:80 (<none>)
TLS:
ingress-ssl-key terminates www.happylauliu.cn
Rules:
Host Path Backends
---- ---- --------
www.happylauliu.cn
/ tke-ingress-ssl-demo:80 (172.16.0.25:80)
Annotations:
qcloud_cert_id: TKPmsWb3
kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"extensions/v1beta1","kind":"Ingress","metadata":{"annotations":{"kubernetes.io/ingress.class":"qcloud","qcloud_cert_id":"TKPmsWb3"},"name":"tke-ingress-ssl","namespace":"default"},"spec":{"rules":[{"host":"www.happylauliu.cn","http":{"paths":[{"backend":{"serviceName":"tke-ingress-ssl-demo","servicePort":80},"path":"/"}]}}],"tls":[{"hosts":["www.happylauliu.cn"],"secretName":"ingress-ssl-key"}]}}
kubernetes.io/ingress.class: qcloud
kubernetes.io/ingress.qcloud-loadbalance-id: lb-2kcrtwbn #CLB的实例id
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal EnsuringIngress 51s (x3 over 73s) loadbalancer-controller Ensuring ingress
Normal CREATE 51s (x2 over 52s) loadbalancer-controller create loadbalancer succ
Normal EnsuredIngress 49s (x3 over 52s) loadbalancer-controller Ensured ingress6、测试验证，hosts文件中解析www.happylauliu.cn到CLB的VIP，或者DNS解析，打开浏览器访问站点，由于是经过CA认证签名的证书，因此没有提示告警信息，查看证书的详情信息
7、查看CLB的配置可得知，CLB上配置了443的监听端口，并关联了证书，采用单向认证方式
通过CLB的配置规则可知，CLB配置了监听443的监听器，80端口并未设置规则，因此此时无法访问http，如何实现在TKE使用ingress实现http和https共存呢，可以通过定义kubernetes.io/ingress.http-rules和
kubernetes.io/ingress.https-rules实现
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: tke-ingress-ssl
annotations:
kubernetes.io/ingress.class: qcloud
kubernetes.io/ingress.rule-mix: "true" #开启混合规则配置，kubernetes.io/ingress.http-rules配置规则
kubernetes.io/ingress.http-rules: ‘[{"host":"www.happylauliu.cn","path":"/","backend":{"serviceName":"tke-ingress-ssl-demo","servicePort":"80"}}]‘
qcloud_cert_id: TKPmsWb3
spec:
rules:
- host: www.happylauliu.cn
http:
paths:
- path: /
backend:
serviceName: tke-ingress-ssl-demo
servicePort: 80
tls:
- hosts:
- www.happylauliu.cn
secretName: ingress-ssl-key设置ingress.http-rules和ingress.https-rules注解之后，会在监听器中创建http和https的转发规则，并绑定RS，此时访问http和https均能实现站点访问，CLB对应的规则内容如下图：
通过测试访问http://www.happylauliu.cn/和https://www.happylauliu.cn/均能正常访问，如果要实现访问http自动跳转到https，则可以在控制台开启自动跳转的功能，如下图：
开启重定向功能后再次访问http站点后此时会自动跳转到https，如下图所示location已经跳转至https://www.happylauliu.cn/
写在最后
通过上述的演示在腾讯云公有云环境下ingress controller的实现，腾讯云TKE通过使用CLB实现和kubernetes ingress集成，借助于service的NodePort实现转发，通过公有云专用的CLB能够最大程度保障ingress接入性能。同时，ingress能够使用腾讯云上的证书实现https加密功能。
参考文献
Ingress配置：https://kubernetes.io/docs/concepts/services-networking/ingress/
Ingress控制器：https://kubernetes.io/docs/concepts/services-networking/ingress-controllers/
ingress基本配置：https://cloud.tencent.com/document/product/457/31711
ingress证书：https://cloud.tencent.com/document/product/457/40538
CLB配置http自动跳转：https://cloud.tencent.com/document/product/214/8839
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