我们前面介绍过用Service做集群代理，Service一般情况下只作用于内部Pod的代理调度，就算有NodePort类型，其访问节点相对复杂，流程大概如下：
但是我们知道，如果只指定一个NodeIP，随着业务量增大，这个Node的压力就会很大，所以我们可能会在前端再加一个代理，代理几个Node，比如我们在前端加一个NG，流程如下：
在应用小的情况下，这种架构虽然调度复杂，但是也可以使用，但是如果有大量应用，这种管理就非常麻烦，因为 我们要管理大量的NodePort，这个时候使用Ingress就非常方便。
再则，Service的转发不论是iptables还是ipvs，都是4层的，但是在实际中基本都https请求，https是7层，4层是没办法对起进行SSL校验的，如果我们是第二幅流程图，我们可以在前置NG上配置SSL，但是如果我们是第一幅图的流程，我们只能在Pod上配置SSL，因为Service上是无法进行校验，那么就会出现一个问题，SSL的校验是很耗资源的，我们的客户端访问Pod，如果Pod非常多并且访问模式是轮询，那么每访问一次就要做一次SSL校验，这就非常不科学，我们就只有用类似于第二副图的架构，Ingress可以很完美的解决这种问题。
一、Ingress
流程图如上，其中Ingress代理的并不是Pod的Service，而是Pod，之所以在配置的时候是配置的Service，是为了获取Pod的信息。
Ingress提供外部访问集群的入口，将外部的HTTP或者HTTPS请求转发到集群内Service上，流量规则是在Ingress资源上定义。
配置Ingress资源的必要条件是你的kubernetes集群种由Ingress controller。其中Ingress Controller常用的有如下：
- HAProxy Ingress Controller
- Nginx Ingress Controller
- Traefik Ingress Controller
- Kong Ingress Controller
其中最常用的是Nginx Controller和Traefik Ingress Controller。
定义一个简单的Ingresss:
[root@master ingress]# cat ingress-simple-daemo.yaml
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: ingress-simple-daemo
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /
spec:
rules:
- http:
paths:
- path: /joker
backend:
serviceName: nginx
servicePort: 80
简要说明：
apiVersion，kind，metadata，spec都是Kubernetes YAML文件的标准字段，Ingress经常通过annotations来配置一些选项，比如rewrite-target，不同的Ingress Controller支持不同的annotations。对于规则而言，每个HTTP都有如下规则：
- 主机：主机是可选参数，如果不配置表示适用于所有主机HTTP通信，如果配置了表示只适用于该主机；
- 路径：类似于NG的location，每个路径后面都有后端ServiceName和ServicePort；
- 后端：后端是ServiceName和ServicePort组合，符合该规则的流量会转发到这个后端Service上。通常会在Ingress中配置默认后端，以匹配任何不符合规则的请求流量转发；
- 具体的语法规则可以通过kubectl explain ingress来查看。
1.1、Ingress 类型
1.1.1、单服务Ingress
Kubernetes中已经存在一些概念可以暴露单个service（查看替代方案），但是你仍然可以通过Ingress来实现，通过指定一个没有rule的默认backend的方式。比如：
[root@master ingress]# cat single-service-ingress.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: single-service-ingress
spec:
backend:
serviceName: nginx
servicePort: 80
1.1.2、简单展开
如前面描述的那样，kubernete pod中的IP只在集群网络内部可见，我们需要在边界设置一个东西，让它能够接收ingress的流量并将它们转发到正确的端点上。这个东西一般是高可用的loadbalancer。使用Ingress能够允许你将loadbalancer的个数降低到最少，例如，假如你想要创建这样的一个设置：
foo.bar.com -> 178.91.123.132 -> / foo service1:4200
/ bar service2:8080
我们就可以这样配置Ingress：
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: simple-fanout-example
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /
spec:
rules:
- host: foo.bar.com
http:
paths:
- path: /foo
backend:
serviceName: service1
servicePort: 4200
- path: /bar
backend:
serviceName: service2
servicePort: 8080
1.1.3、基于名称的虚拟主机
如果想实现下面这种需求：
foo.bar.com --| |-> foo.bar.com s1:80
| 178.91.123.132 |
bar.foo.com --| |-> bar.foo.com s2:80
我们就可以这样配置Ingress:
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: name-virtual-host-ingress
spec:
rules:
- host: foo.bar.com
http:
paths:
- backend:
serviceName: service1
servicePort: 80
- host: bar.foo.com
http:
paths:
- backend:
serviceName: service2
servicePort: 80
如果要增加配置默认的backend，可以配置成如下Ingress：
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: name-virtual-host-ingress
spec:
rules:
- host: first.bar.com
http:
paths:
- backend:
serviceName: service1
servicePort: 80
- host: second.foo.com
http:
paths:
- backend:
serviceName: service2
servicePort: 80
- http:
paths:
- backend:
serviceName: service3
servicePort: 80
默认backend：一个没有rule的ingress，所有流量都将发送到一个默认backend。你可以用该技巧通知loadbalancer如何找到你网站的404页面，通过制定一些列rule和一个默认backend的方式。如果请求header中的host不能跟ingress中的host匹配，并且/或请求的URL不能与任何一个path匹配，则流量将路由到你的默认backend。
1.1.4、TLS
你可以通过指定包含TLS私钥和证书的secret来加密Ingress。 目前，Ingress仅支持单个TLS端口443，并假定TLS termination。 如果Ingress中的TLS配置部分指定了不同的主机，则它们将根据通过SNI TLS扩展指定的主机名（假如Ingress controller支持SNI）在多个相同端口上进行复用。 TLS secret中必须包含名为tls.crt和tls.key的密钥，这里面包含了用于TLS的证书和私钥，例如：
apiVersion: v1
kind: Secret
metadata:
name: testsecret-tls
namespace: default
data:
tls.crt: base64 encoded cert
tls.key: base64 encoded key
type: kubernetes.io/tls
在Ingress中引用这个secret将通知Ingress controller使用TLS加密从将客户端到loadbalancer的channel：
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: tls-example-ingress
spec:
tls:
- hosts:
- sslexample.foo.com
secretName: testsecret-tls
rules:
- host: sslexample.foo.com
http:
paths:
- path: /
backend:
serviceName: service1
servicePort: 80
注意：各种Ingress controller支持的TLS功能之间存在差距。 请参阅有关nginx，GCE或任何其他平台特定Ingress controller的文档，以了解TLS在你的环境中的工作原理。
1.2、Ingress更新
如果你想更改你现在正工作的Ingress，比如新增一个HOST，可以使用kubectl edit ingress my-ingress进行更新，在保存退出后其会触发Ingress Controller重新配置LB。比如我们现有一个ingress：
[root@master ingress]# kubectl get ingresses.
NAME HOSTS ADDRESS PORTS AGE
* 80 58m
然后我们使用kubectl edit ingress ingress-simple-daemo来新增一个HOST：
......
spec:
rules:
- http:
paths:
- backend:
serviceName: nginx-service
servicePort: 8000
path: /joker
- host: bar.baz.com
http:
paths:
- backend:
serviceName: nginx
servicePort: 80
path: /foo
status:
loadBalancer: {}
保存退出后就会生效：
[root@master ingress]# kubectl describe ingresses ingress-simple-daemo
Name: ingress-simple-daemo
Namespace: default
Address:
Default backend: default-http-backend:80 (<none>)
Rules:
Host Path Backends
---- ---- --------
*
/joker nginx-service:8000 (172.20.2.84:80)
bar.baz.com
/foo nginx:80 (172.20.2.79:80,172.20.2.82:80)
Annotations:
kubernetes.io/ingress.class: traefik
kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"networking.k8s.io/v1beta1","kind":"Ingress","metadata":{"annotations":{"kubernetes.io/ingress.class":"traefik"},"name":"ingress-simple-daemo","namespace":"default"},"spec":{"rules":[{"http":{"paths":[{"backend":{"serviceName":"nginx-service","servicePort":8000},"path":"/joker"}]}}]}}
Events: <none>
二、Nginx Ingress
2.1、安装
2.1.1 在线安装
在线安装直接执行以下命令：
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/static/mandatory.yaml
然后安装NodePort：
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/static/provider/baremetal/service-nodeport.yaml
2.1.2、离线安装
到https://github.com/kubernetes/ingress-nginx/tree/master/deploy/static这个下面下载对应的YAML文件，有configmap.yaml，namespace.yaml，rbac.yaml，with-rbac.yaml，可以写一个如下循环下载：
for yaml in configmap.yaml namespace.yaml rbac.yaml with-rbac.yaml; do wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/static/$yaml;done
然后执行如下命令安装，前提先执行namespace.yaml这个YAML文件：
kubectl apply -f namespace.yaml
kubectl apply -f .
然后我们可以执行以下命令查看：
[root@master nginx]# kubectl get pod -n ingress-nginx
NAME READY STATUS RESTARTS AGE
nginx-ingress-controller-799dbf6fbd-zxvmp 0/1 ContainerCreating 0 12s
然后安装nodePort:
wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/static/provider/baremetal/service-nodeport.yaml
kubectl apply -f service-nodeport.yaml
然后我修改了nodePort的端口，如下：
apiVersion: v1
kind: Service
metadata:
name: ingress-nginx
namespace: ingress-nginx
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
spec:
type: NodePort
ports:
- name: http
port: 80
targetPort: 80
nodePort: 30080
protocol: TCP
- name: https
port: 443
targetPort: 443
nodePort: 30443
protocol: TCP
selector:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
---
然后查看结果：
[root@master nginx]# kubectl get pod -n ingress-nginx
NAME READY STATUS RESTARTS AGE
nginx-ingress-controller-799dbf6fbd-zxvmp 1/1 Running 0 52m
[root@master nginx]# kubectl get svc -n ingress-nginx
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
ingress-nginx NodePort 10.68.194.177 <none> 80:30080/TCP,443:30443/TCP 46m
2.2、使用
先创建Pod，service，定义如下YAML：
[root@master test]# cat nginx-ingress-demo.yaml
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx-deploy
namespace: default
spec:
replicas: 3
selector:
matchLabels:
app: nginx-demo
release: canary
template:
metadata:
name: my-nginx
labels:
app: nginx-demo
release: canary
spec:
containers:
- name: my-nginx
image: nginx
imagePullPolicy: IfNotPresent
ports:
- name: http
containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: nginx-svc
namespace: default
spec:
selector:
app: nginx-demo
release: canary
ports:
- name: http
port: 80
targetPort: 80
然后执行kubectl apply -f nginx-ingress-demo.yaml，查看结果：
[root@master test]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-deploy-549cb5c7ff-65fbb 1/1 Running 0 21s
nginx-deploy-549cb5c7ff-75fmt 1/1 Running 0 21s
nginx-deploy-549cb5c7ff-wg4w7 1/1 Running 0 17s
[root@master test]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.68.0.1 <none> 443/TCP 5d2h
nginx-svc ClusterIP 10.68.214.28 <none> 80/TCP 6m21s
然后定义Ingress Nginx，YAML文件如下：
[root@master test]# cat ingress-nginx.yaml
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: ingress-nginx
annotations:
kubernetes.io/ingress.class: "nginx"
spec:
rules:
- host:
http:
paths:
- path:
backend:
serviceName: nginx-svc
servicePort: 80
然后查看结果：
[root@master test]# kubectl describe ingresses ingress-nginx
Name: ingress-nginx
Namespace: default
Address: 10.68.194.177
Default backend: default-http-backend:80 (<none>)
Rules:
Host Path Backends
---- ---- --------
*
nginx-svc:80 (172.20.1.61:80,172.20.1.62:80,172.20.2.87:80)
Annotations:
kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"networking.k8s.io/v1beta1","kind":"Ingress","metadata":{"annotations":{"kubernetes.io/ingress.class":"nginx"},"name":"ingress-nginx","namespace":"default"},"spec":{"rules":[{"host":null,"http":{"paths":[{"backend":{"serviceName":"nginx-svc","servicePort":80},"path":null}]}}]}}
kubernetes.io/ingress.class: nginx
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal CREATE 11m nginx-ingress-controller Ingress default/ingress-nginx
Normal UPDATE 77s (x3 over 11m) nginx-ingress-controller Ingress default/ingress-nginx
在流量器访问：
2.3、TLS
Nginx Ingress不止支持HTTP，还支持HTTPS。我们使用如下命令手动创建证书：
openssl genrsa -out tls.key 2048
openssl req -new -x509 -key tls.key -out tls.crt -subj "/C=CN/ST=Chongqing/L=Chongqing/OU=DevOps/CN=nginx.joker.com"
然后配置Secrect：
kubectl create secret tls tls-secret --key tls.key --cert tls.crt
然后查看：
[root@master test]# kubectl get secret
NAME TYPE DATA AGE
default-token-gmdbb kubernetes.io/service-account-token 3 5d3h
tls-secret kubernetes.io/tls 2 20s
[root@master test]# kubectl describe secrets tls-secret
Name: tls-secret
Namespace: default
Labels: <none>
Annotations: <none>
Type: kubernetes.io/tls
Data
====
tls.crt: 1302 bytes
tls.key: 1679 bytes
配置Ingress nginx:
[root@master test]# cat ingress-nginx-tls.yaml
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: ingress-nginx-tls
annotations:
kubernetes.io/ingress.class: "nginx"
spec:
tls:
- host:
secretName: tls-secret
rules:
- host:
http:
paths:
- path:
backend:
serviceName: nginx-svc
servicePort: 80
然后查看结果：
[root@master test]# kubectl get ingresses.
NAME HOSTS ADDRESS PORTS AGE
ingress-nginx-tls * 80, 443 4s
浏览器访问：
三、Traefik Ingress
3.1、安装
创建namespace（namespace.yaml）：
apiVersion: v1
kind: Namespace
metadata:
name: ingress-traefik
labels:
app.kubernetes.io/name: ingress-traefik
app.kubernetes.io/part-of: ingress-traefik
---
创建RBAC安全认证（rdac.yaml）：
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: traefik-ingress-controller
namespace: ingress-traefik
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: traefik-ingress-controller
rules:
- apiGroups:
- ""
resources:
- services
- endpoints
- secrets
verbs:
- get
- list
- watch
- apiGroups:
- extensions
resources:
- ingresses
verbs:
- get
- list
- watch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: traefik-ingress-controller
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: traefik-ingress-controller
subjects:
- kind: ServiceAccount
name: traefik-ingress-controller
namespace: ingress-traefik
配置traefik（traefik.yaml）：
---
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
name: traefik-ingress-controller
namespace: ingress-traefik
labels:
k8s-app: traefik-ingress-lb
spec:
replicas: 1
selector:
matchLabels:
k8s-app: traefik-ingress-lb
template:
metadata:
labels:
k8s-app: traefik-ingress-lb
name: traefik-ingress-lb
spec:
serviceAccountName: traefik-ingress-controller
terminationGracePeriodSeconds: 60
# tolerations:
# - operator: "Exists"
# nodeSelector:
# kubernetes.io/hostname: master
containers:
- image: traefik:v1.7.17
name: traefik-ingress-lb
ports:
- name: http
containerPort: 80
- name: admin
containerPort: 8080
args:
- --api
- --kubernetes
- --logLevel=INFO
---
kind: Service
apiVersion: v1
metadata:
name: traefik-ingress-service
namespace: ingress-traefik
spec:
selector:
k8s-app: traefik-ingress-lb
ports:
- protocol: TCP
port: 80
name: web
nodePort: 38000
- protocol: TCP
port: 8080
nodePort: 38080
name: admin
type: NodePort
然后执行如下命令创建：
kubectl apply -f .
查看其结果：
[root@master traefik]# kubectl get svc -n ingress-traefik
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
traefik-ingress-service NodePort 10.68.173.196 <none> 80:38000/TCP,8080:38080/TCP 9m19s
[root@master traefik]# kubectl get pod -n ingress-traefik
NAME READY STATUS RESTARTS AGE
traefik-ingress-controller-86769d5d99-fvf82 1/1 Running 0 7m10s
Traefik提供一个WEB UI工具，就是上面8080端口，可以通过其映射的NodePort端口在浏览器访问，如下：
3.2、使用
使用和上面nginx ingress一样，只是在annotations里配置的kubernetes.io/ingress.class: "traefik"。
3.3、配置
生成SSL证书：
openssl req -newkey rsa:2048 -nodes -keyout tls.key -x509 -days 365 -out tls.crt
创建Secret来存储证书：
# kubectl create secret generic traefik-cert --from-file=tls.crt --from-file=tls.key -n ingress-traefik
配置traefik，让其支持https，配置文件如下：
defaultEntryPoints = ["http", "https"]
[entryPoints]
[entryPoints.http]
address = ":80"
[entryPoints.http.redirect]
entryPoint = "https"
[entryPoints.https]
address = ":443"
[entryPoints.https.tls]
[[entryPoints.https.tls.certificates]]
CertFile = "/ssl/tls.crt"
KeyFile = "/ssl/tls.key"
将上面的 traefik.toml 配置文件通过一个 ConfigMap 对象挂载到 traefik pod 中去。
创建configMap：
# kubectl create configmap traefik-conf --from-file=traefik.toml -n ingress-traefik
更改traefik的YAML文件：
---
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
name: traefik-ingress-controller
namespace: ingress-traefik
labels:
k8s-app: traefik-ingress-lb
spec:
replicas: 1
selector:
matchLabels:
k8s-app: traefik-ingress-lb
name: traefik-ingress-lb
template:
metadata:
labels:
k8s-app: traefik-ingress-lb
name: traefik-ingress-lb
spec:
serviceAccountName: traefik-ingress-controller
terminationGracePeriodSeconds: 60
# tolerations:
# - operator: "Exists"
# nodeSelector:
# kubernetes.io/hostname: master
containers:
- image: traefik:v1.7.17
name: traefik-ingress-lb
volumeMounts:
- name: ssl
mountPath: "/ssl"
- name: config
mountPath: "/config"
ports:
- name: http
containerPort: 80
- name: https
containerPort: 443
- name: admin
containerPort: 8080
args:
- --configfile=/config/traefik.toml
- --api
- --kubernetes
- --logLevel=INFO
volumes:
- name: ssl
secret:
secretName: traefik-cert
- name: config
configMap:
name: traefik-conf
---
kind: Service
apiVersion: v1
metadata:
name: traefik-ingress-service
namespace: ingress-traefik
spec:
selector:
k8s-app: traefik-ingress-lb
ports:
- protocol: TCP
port: 80
name: web
nodePort: 38000
- protocol: TCP
port: 8080
nodePort: 38080
name: admin
type: NodePort
然后生成配置清单，并查看日志观察其是否生效；
# kubectl apply -f traefik.yaml
# kubectl logs traefik-ingress-controller-867f5668dd-7p7tv -n ingress-traefik
time="2019-11-25T08:25:30Z" level=info msg="Using TOML configuration file /config/traefik.toml"
time="2019-11-25T08:25:30Z" level=info msg="No tls.defaultCertificate given for https: using the first item in tls.certificates as a fallback."
time="2019-11-25T08:25:30Z" level=info msg="Traefik version v1.7.17 built on 2019-09-23_06:22:08PM"
time="2019-11-25T08:25:30Z" level=info msg="
Stats collection is disabled.
Help us improve Traefik by turning this feature on :)
More details on: https://docs.traefik.io/v1.7/basics/#collected-data
"
time="2019-11-25T08:25:30Z" level=info msg="Preparing server https &{Address::443 TLS:0xc0002b22d0 Redirect:<nil> Auth:<nil> WhitelistSourceRange:[] WhiteList:<nil> Compress:false ProxyProtocol:<nil> ForwardedHeaders:0xc00050a100} with readTimeout=0s writeTimeout=0s idleTimeout=3m0s"
time="2019-11-25T08:25:30Z" level=info msg="Preparing server traefik &{Address::8080 TLS:<nil> Redirect:<nil> Auth:<nil> WhitelistSourceRange:[] WhiteList:<nil> Compress:false ProxyProtocol:<nil> ForwardedHeaders:0xc00050a120} with readTimeout=0s writeTimeout=0s idleTimeout=3m0s"
time="2019-11-25T08:25:30Z" level=info msg="Starting server on :443"
time="2019-11-25T08:25:30Z" level=info msg="Preparing server http &{Address::80 TLS:<nil> Redirect:0xc000843fc0 Auth:<nil> WhitelistSourceRange:[] WhiteList:<nil> Compress:false ProxyProtocol:<nil> ForwardedHeaders:0xc00050a0e0} with readTimeout=0s writeTimeout=0s idleTimeout=3m0s"
time="2019-11-25T08:25:30Z" level=info msg="Starting server on :8080"
time="2019-11-25T08:25:30Z" level=info msg="Starting provider configuration.ProviderAggregator {}"
time="2019-11-25T08:25:30Z" level=info msg="Starting server on :80"
time="2019-11-25T08:25:30Z" level=info msg="Starting provider *kubernetes.Provider {"Watch":true,"Filename":"","Constraints":[],"Trace":false,"TemplateVersion":0,"DebugLogGeneratedTemplate":false,"Endpoint":"","Token":"","CertAuthFilePath":"","DisablePassHostHeaders":false,"EnablePassTLSCert":false,"Namespaces":null,"LabelSelector":"","IngressClass":"","IngressEndpoint":null,"ThrottleDuration":0}"
time="2019-11-25T08:25:30Z" level=info msg="ingress label selector is: """
time="2019-11-25T08:25:30Z" level=info msg="Creating in-cluster Provider client"
time="2019-11-25T08:25:30Z" level=info msg="Server configuration reloaded on :443"
time="2019-11-25T08:25:30Z" level=info msg="Server configuration reloaded on :8080"
time="2019-11-25T08:25:30Z" level=info msg="Server configuration reloaded on :80"
3.4、Rewrite
测试demo：
apiVersion: v1
kind: Service
metadata:
name: nginx-demo
spec:
selector:
app: nginx
ports:
- name: nginx
port: 80
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx
labels:
app: nginx
spec:
replicas: 2
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx
imagePullPolicy: IfNotPresent
正常访问的ingress如下：
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: nginx-ingress-demo
annotations:
kubernetes.io/ingress.class: "traefik"
spec:
rules:
- host:
http:
paths:
- backend:
serviceName: nginx-demo
servicePort: 80
path: /
但是如果我们把path改为如下：
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: nginx-ingress-demo
annotations:
kubernetes.io/ingress.class: "traefik"
spec:
rules:
- host:
http:
paths:
- backend:
serviceName: nginx-demo
servicePort: 80
path: /app
那么这时候访问就会报404.
这时候我们可以在配置里加上rewrite规则，如下：
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: nginx-ingress-demo
annotations:
kubernetes.io/ingress.class: "traefik"
traefik.ingress.kubernetes.io/rewrite-target: /
spec:
rules:
- host:
http:
paths:
- backend:
serviceName: nginx-demo
servicePort: 80
path: /app
然后就可以正常访问了，如下：
为了更友好化，我们可以定义如下：
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: nginx-ingress-demo
annotations:
kubernetes.io/ingress.class: "traefik"
traefik.ingress.kubernetes.io/rewrite-target: /$2
spec:
rules:
- host:
http:
paths:
- backend:
serviceName: nginx-demo
servicePort: 80
path: /app(/|$)(.*)
但是这种还是会有问题，比如有的静态资源无法正常显示，比如静态资源的路径在/static下面，现在我们做了 url rewrite 过后，要正常访问也需要带上前缀才可以：http://xxx.xxx/static/screen.css，对于图片或者其他静态资源也是如此，当然我们去更改页面引入静态资源的方式为相对路径也是可以的，但是毕竟要修改代码，这个时候我们可以借助 ingress-traefik 中的 configuration-snippet 来对静态资源做一次跳转，如下所示： ```yaml apiVersion: extensions/v1beta1 kind: Ingress metadata: name: nginx-ingress-demo annotations: kubernetes.io/ingress.class: "traefik" traefik.ingress.kubernetes.io/rewrite-target: /$2 traefik.ingress.kubernetes.io/configuration-snippet: | rewrite ^/static/(.*)$ /app/static/$1 redirect; rewrite ^/image/(.*)$ /app/image/$1 redirect; spec: rules: - host: http: paths: - backend: serviceName: nginx-demo servicePort: 80 path: /app(/|$)(.*) ```
这时候就可以正常加载静态资源了。
但是我们还想直接访问主域名，但是会报404，要解决这种问题，可以app-root的注解，这样我们访问主域名的时候就可以跳转到app-root目录（真实存在的路径）下面，如下：
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: nginx-ingress-demo
annotations:
kubernetes.io/ingress.class: "traefik"
traefik.ingress.kubernetes.io/app-root: /app/
traefik.ingress.kubernetes.io/rewrite-target: /$2
traefik.ingress.kubernetes.io/configuration-snippet: |
rewrite ^/static/(.*)$ /app/static/$1 redirect;
rewrite ^/image/(.*)$ /app/image/$1 redirect;
spec:
rules:
- host:
http:
paths:
- backend:
serviceName: nginx-demo
servicePort: 80
path: /app(/|$)(.*)
但是还有一个问题是我们的 path 路径其实也匹配了 /app 这样的路径，可能我们更加希望我们的应用在最后添加一个 / 这样的 slash，同样我们可以通过 configuration-snippet 配置来完成，如下 Ingress 对象：
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: nginx-ingress-demo
annotations:
kubernetes.io/ingress.class: "traefik"
traefik.ingress.kubernetes.io/app-root: /app/
traefik.ingress.kubernetes.io/rewrite-target: /$2
traefik.ingress.kubernetes.io/configuration-snippet: |
rewrite ^(/app)$ $1/ redirect;
rewrite ^/static/(.*)$ /app/static/$1 redirect;
rewrite ^/image/(.*)$ /app/image/$1 redirect;
spec:
rules:
- host:
http:
paths:
- backend:
serviceName: nginx-demo
servicePort: 80
path: /app(/|$)(.*)