kubernetes使用traefik的https方式访问web应用

背景
之前的文章中，我已经利用kubernetes的traefik服务作为入口，访问了tomcat的相关 服务，但之前的文章是通过http的方式来访问的。在现实应用中，为了安全考虑，肯定有https访问的需求，这里我们就通过traefik来实现https的访问。
之前的文章链接：http://blog.51cto.com/icenycmh/2124502

实验操作
一：想开启https，证书是少不了的。可以自己手动建一个证书，或者利用已经有的证书。这里我用已经申请的一个ssl证书，对应的域名为*.gzshapp.com。

二：创建一个secret，保存https证书。

# ll
total 12
-rw-r--r-- 1 root root 5477 Mar 30 16:32 _.gzshapp.com_bundle.crt
-rw-r--r-- 1 root root 1708 Mar 28 14:01 _.gzshapp.com.key

# kubectl create secret generic traefik-cert --from-file=_.gzshapp.com_bundle.crt --from-file=_.gzshapp.com.key -n kube-system

把证书拷贝到k8s node节点，本例中，存放证书的目录为：/opt/conf/k8s/ssl/。

三：创建一个configmap，保存traefix的配置。
这里的traefix中配置了把所有http请求全部rewrite为https的规则，并配置相应的证书位置：

# vi traefik.toml
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 = "/opt/conf/k8s/ssl/_.gzshapp.com_bundle.crt"
 keyFile = "/opt/conf/k8s/ssl/_.gzshapp.com.key" # kubectl create configmap traefik-conf --from-file=traefik.toml -n kube-system 

把traefik.toml文件拷贝到k8s node节点，本例中，traefik的存放目录为：/opt/conf/k8s/conf/。

四：重新部署Traefix，这里主要是要关联创建的secret和configMap，并挂载相对应的主机目录。

# more traefik-deployment.yaml  apiVersion: extensions/v1beta1 kind: Deployment metadata:
 name: traefik-ingress-lb
 namespace: kube-system
 labels:
 k8s-app: traefik-ingress-lb
spec:
 replicas: 2
 template:
 metadata:
 labels:
 k8s-app: traefik-ingress-lb
 name: traefik-ingress-lb
 spec:
 terminationGracePeriodSeconds: 60
 volumes:
 - name: ssl
 secret:
 secretName: traefik-cert
 - name: config
 configMap:
 name: traefik-conf
 hostNetwork: true
 restartPolicy: Always
 serviceAccountName: ingress
 containers:
 - image: traefik
 name: traefik-ingress-lb
 volumeMounts:
 - mountPath: "/opt/conf/k8s/ssl"
 name: "ssl"
 - mountPath: "/opt/conf/k8s/conf"
 name: "config"
 ports:
 - name: http
 containerPort: 80
 hostPort: 80
 - name: admin
 containerPort: 8580
 hostPort: 8580
 args:
 - --configFile=/opt/conf/k8s/conf/traefik.toml
 - --web
 - --web.address=:8580
 - --kubernetes

# kubectl apply -f traefik-deployment.yaml 

五：测试效果。
这里我们可以登陆traefik-ui界面，可以看到原本http的访问，traefik会直接给我们重定向至https。

# vi ingress-tomcat.yaml 
---
apiVersion: extensions/v1beta1 kind: Ingress metadata:
 name: tomcat-test-web
 namespace: default
 annotations:
 kubernetes.io/ingress.class: traefik
 traefik.frontend.rule.type: PathPrefixStrip
spec:
 rules:
 - host: test.gzshapp.com
 http:
 paths:
 - path: /test1/
 backend:
 serviceName: tomcat-test1
 servicePort: 8080
 - path: /test2/
 backend:
 serviceName: tomcat-test2
 servicePort: 8080

# kubectl apply -f ingress-tomcat.yaml 

这里我们修改ingress的域名为test.gzshapp.com，修改一下host，再访问测试一下：

192.168.232.129 test.gzshapp.com
192.168.232.131 test.gzshapp.com

其他需求
当然，现实环境中肯定针对不同情况，有很多的不同需求。比如，访问需同时支持http和https、只有部分域名需要https强制跳转，后端代理https的应用等。这里我们可以一个个来根据需求配置traefik。
1：同时支持http和https：(把http中的rewrite代码改掉)

defaultEntryPoints = ["http","https"]
[entryPoints]
 [entryPoints.http]
 address = ":80"
 entryPoint = "https"
 [entryPoints.https]
 address = ":443"
 [entryPoints.https.tls]
 [[entryPoints.https.tls.certificates]]
 certFile = "/opt/scripts/traefik/https/_.gzshapp.com_bundle.crt"
 keyFile = "/opt/scripts/traefik/https/_.gzshapp.com.key"

2：仅配置部分域名强制跳转https：(在http.redirect中编写对应域名的正则)

defaultEntryPoints = ["http","https"]
[entryPoints]
 [entryPoints.http]
 address = ":80"
 [entryPoints.http.redirect]
 regex = "^http://test.gzshapp.com/(.*)"
 replacement = "https://test.gzshapp.com/$1"
 [entryPoints.https]
 address = ":443"
 [entryPoints.https.tls]
 [[entryPoints.https.tls.certificates]]
 certFile = "/opt/conf/k8s/ssl/_.gzshapp.com_bundle.crt"
 keyFile = "/opt/conf/k8s/ssl/_.gzshapp.com.key"

3：traefik代理后端https请求：
这里我修改了一下我的tomcat服务，开放了8443的https端口，并修改了一下ingress的配置，如下：

insecureSkipVerify = true
defaultEntryPoints = ["http","https"]
[entryPoints]
 [entryPoints.http]
 address = ":80"
 entryPoint = "https"
 [entryPoints.https]
 address = ":443"
 [entryPoints.https.tls]
 [[entryPoints.https.tls.certificates]]
 certFile = "/opt/conf/k8s/ssl/_.gzshapp.com_bundle.crt"
 keyFile = "/opt/conf/k8s/ssl/_.gzshapp.com.key"