kubernetes之部署traefik-ingress分为http和https
1 理解Ingress
简单的说,ingress就是从kubernetes集群外访问集群的入口,将用户的URL请求转发到不同的service上。Ingress相当于nginx、apache等负载均衡方向代理服务器,其中还包括规则定义,即URL的路由信息,路由信息得的刷新由Ingress controller来提供。
2 理解Ingress Controller
Ingress Controller 实质上可以理解为是个监视器,Ingress Controller 通过不断地跟 kubernetes API 打交道,实时的感知后端 service、pod 等变化,比如新增和减少 pod,service 增加与减少等;当得到这些变化信息后,Ingress Controller 再结合下文的 Ingress 生成配置,然后更新反向代理负载均衡器,并刷新其配置,达到服务发现的作用。
3 RBAC
在开始之前,需要先了解一下什么是RBAC。RBAC(基于角色的访问控制)使用 rbac.authorization.k8s.io API 组来实现权限控制,RBAC 允许管理员通过 Kubernetes API 动态的配置权限策略。在 1.6 版本中 RBAC 还处于 Beat 阶段,如果想要开启 RBAC 授权模式需要在 apiserver 组件中指定 --authorization-mode=RBAC 选项。
在 RBAC API 的四个重要概念:
Role:是一系列的权限的集合,例如一个角色可以包含读取 Pod 的权限和列出 Pod 的权限
ClusterRole: 跟 Role 类似,但是可以在集群中到处使用( Role 是 namespace 一级的)
RoloBinding:把角色映射到用户,从而让这些用户继承角色在 namespace 中的权限。
ClusterRoleBinding: 让用户继承 ClusterRole 在整个集群中的权限。
4 部署traefik
首先部署一个 ingress controller 类型的 pod,pod中运行的容器是traefik,然后选择是通过基于不同的域名或者不同的 URL,关联到不同的 service。而后通过 ingress 来监控 service 的变化,最终形成相应的配置文件。
4.1 创建ingress-rbac.yaml
将用于service account验证。部署之前先创建 clusterRoleBinding,它的作用是将下面列出的权限授予给 traefik-ingress-controller 这个 ServiceAccount,然后 pod 就由这个用户启动。这样一来,pod 就拥有这些权限了。
$ cat ingress-rbac.yaml apiVersion: v1 kind: ServiceAccount metadata: name: ingress namespace: kube-system --- kind: ClusterRoleBinding apiVersion: rbac.authorization.k8s.io/v1beta1 metadata: name: ingress subjects: - kind: ServiceAccount name: ingress namespace: kube-system roleRef: kind: ClusterRole name: cluster-admin apiGroup: rbac.authorization.k8s.io
4.2 创建DaemonSet
traefik 可以部署为 Deployment 和 DaemonSet 两种模式,如果使用官方提供的 deployment 的安装方式,traefik pod 的 80/443/8080 端口会通过 NodePort 的方式暴露出来,也就是说你无法通过节点的 ip + 80 端口进行访问,因此你前面还得给它加上一个负载均衡器。
而官方的 DaemonSet 就不存在这样的问题了,它使用的是 NET_BIND_SERVICE 这样一个 capabilities,意思是可以直接使用宿主机网络名称空间的端口。使用它之后,你在宿主机上看不到它监听了 80 端口,但是你却可以直接访问,而不是 Deployment 这样的 NodePort 方式。但是 DaemonSet 的缺点也很明显,你的 node 节点数量越多,就越消耗资源。
有没有两全其美的方法呢?那肯定是有的,无论你使用 Deployment 还是 DaemonSet,只要都使用 NET_BIND_SERVICE,然后定义好节点的亲和性或者污点就能让 pod 只运行在特定的节点上,然后域名解析指向这些节点就行。当然前提是这些节点的 80/443 都没有被占用。
我们使用DaemonSet类型来部署Traefik,并使用nodeSelector来限定Traefik所部署的主机。
4.2.1 创建节点标签
选择节点来调度traefik-ingress-lb运行在它上面
kubectl label nodes 172.19.8.114 edgenode=true kubectl label nodes 172.19.8.115 edgenode=true
4.2.2 部署traefik-ingress-controller.yml
apiVersion: extensions/v1beta1 kind: DaemonSet metadata: name: traefik-ingress-lb namespace: kube-system labels: k8s-app: traefik-ingress-lb spec: template: metadata: labels: k8s-app: traefik-ingress-lb name: traefik-ingress-lb spec: terminationGracePeriodSeconds: 60 hostNetwork: true restartPolicy: Always serviceAccountName: ingress containers: - image: traefik name: traefik-ingress-lb resources: limits: cpu: 200m memory: 30Mi requests: cpu: 100m memory: 20Mi ports: - name: http containerPort: 80 hostPort: 80 - name: admin containerPort: 8080 hostPort: 8080 args: - --web - --web.address=:8080 - --kubernetes - --insecureskipverify nodeSelector: edgenode: "true"
4.3 配置traefik UI
使用下面的yaml配置来创建Traefik的Web UI。
$ cat ui.yaml apiVersion: v1 kind: Service metadata: name: traefik-web-ui namespace: kube-system spec: selector: k8s-app: traefik-ingress-lb ports: - name: web port: 80 targetPort: 8580 --- apiVersion: extensions/v1beta1 kind: Ingress metadata: name: traefik-web-ui namespace: kube-system spec: rules: - host: traefikui.test.com http: paths: - path: / backend: serviceName: traefik-web-ui servicePort: web
配置完成后就可以启动treafik ui ingress了。
这其中的backend中要配置default namespace中启动的service名字,如果你没有配置namespace名字,默认使用default namespace,如果你在其他namespace中创建服务想要暴露到kubernetes集群外部,可以创建新的ingress.yaml文件,同时在文件中指定该namespace,其他配置与上面的文件格式相同。。path就是URL地址后的路径,如traefik.frontend.io/path,service将会接受path这个路径,host最好使用service-name.filed1.filed2.domain-name这种类似主机名称的命名方式,方便区分服务。
根据你自己环境中部署的service的名字和端口自行修改,有新service增加时,修改该文件后可以使用kubectl replace -f ui.yaml来更新。
4.3.1 访问测试
修改本地hosts 172.19.8.115 traefikui.test.com
5 配置traefik支持https
5.1 https介绍
设置https有2种方式
1、 client与traefik间采用https加密通信,但traefik与svc间则是明文的http通信
client --- (via https) ---> traefik ---- (via http) ----> services
2、 client与traefik间采用https加密通信,但traefik与svc也是采用https通信
client --- (via https) ---> traefik ---- (via https) ----> services
5.2 配置证书
证书本地存放路径 /etc/kubernetes/ssl/
# mkdir /etc/kubernetes/ssl/ # cd /etc/kubernetes/ssl/ # 将证书存放在此目录 # ls pt1.20201216.key pt1.20201216.pem
5.3 创建secret,保存https证书,注意操作目录,如果不是在此目录下操作,须指定绝对路径,同时配置traefik多域名证书形式,traefik能够自动识别证书
[root@node-01 ssl]# kubectl create secret generic traefik-cert --from-file=/etc/kubernetes/ssl/pt1.20201216.key --from-file=/etc/kubernetes/ssl/pt1.20201216.pem
--from-file=/etc/kubernetes/ssl/pt2.20201216.key --from-file=/etc/kubernetes/ssl/pt2.20201216.pem
-n kube-system
5.4 创建configmap,保存traefik配置
说明:此处两种配置方式,1.所有http请求全部rewrite为https。2.区分http和https两种请求。此处使用第二种
# 1.所有http请求全部rewrite为https [root@node-01 traefik]# cat 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 = "/etc/kubernetes/ssl/pt1.20201216.pem" keyFile = "/etc/kubernetes/ssl/pt1.20201216.key"
[[entryPoints.https.tls.certificates]]
certFile = "/etc/kubernetes/ssl/pt2.20201216.pem"
keyFile = "/etc/kubernetes/ssl/pt2.20201216.key"
# 2.区分http和https两种请求 [root@node-01 traefik]# cat traefik.toml defaultEntryPoints = ["http","https"] [entryPoints] [entryPoints.http] address = ":80" entryPoint = "https" [entryPoints.https] address = ":443" [entryPoints.https.tls] [[entryPoints.https.tls.certificates]] certFile = "/etc/kubernetes/ssl/pt1.20201216.pem" keyFile = "/etc/kubernetes/ssl/pt1.20201216.key"
[[entryPoints.https.tls.certificates]]
certFile = "/etc/kubernetes/ssl/pt2.20201216.pem"
keyFile = "/etc/kubernetes/ssl/pt2.20201216.key"
注意:部署traefik.toml的节点,需要根据traefik.toml中指明的位置存放证书文件
[root@node-01 traefik]# kubectl create configmap traefik-conf --from-file=traefik.toml -n kube-system
[root@node-01 traefik]# kubectl get cm -n kube-system
NAME DATA AGE
traefik-conf 1 13s
查看创建的configmap
[root@node-01 traefik]# kubectl get configmap traefik-conf -o yaml -n kube-system apiVersion: v1 data: traefik.toml: | defaultEntryPoints = ["http","https"] [entryPoints] [entryPoints.http] address = ":80" entryPoint = "https" [entryPoints.https] address = ":443" [entryPoints.https.tls] [[entryPoints.https.tls.certificates]] certFile = "/etc/kubernetes/ssl/pt1.20201216.pem" keyFile = "/etc/kubernetes/ssl/pt1.20201216.key"
[[entryPoints.https.tls.certificates]]
certFile = "/etc/kubernetes/ssl/pt2.20201216.pem"
keyFile = "/etc/kubernetes/ssl/pt2.20201216.key"
kind: ConfigMap metadata: creationTimestamp: "2019-05-07T11:31:07Z" name: traefik-conf namespace: kube-system resourceVersion: "222740" selfLink: /api/v1/namespaces/kube-system/configmaps/traefik-conf uid: 9b315499-70bb-11e9-9a10-fa0caed1a100
5.5 部署traefik,这里主要是要关联创建的secret和configmap,并挂载到pod中的目录。
5.5.1 为主机打标签,确定traefik部署在哪些node上面
kubectl label nodes 172.19.8.114 edgenode=true kubectl label nodes 172.19.8.115 edgenode=true
5.5.2 由于k8s启用了rbac,因此需要创建权限
[root@node-01 traefik]# cat ingress-rbac.yaml apiVersion: v1 kind: ServiceAccount metadata: name: traefik-ingress-controller namespace: kube-system --- kind: ClusterRoleBinding apiVersion: rbac.authorization.k8s.io/v1beta1 metadata: name: traefik-ingress-controller subjects: - kind: ServiceAccount name: traefik-ingress-controller namespace: kube-system roleRef: kind: ClusterRole name: cluster-admin apiGroup: rbac.authorization.k8s.io
我们使用DaemonSet类型来部署Traefik,并使用nodeSelector来限定Traefik所部署的主机。
[root@node-01 traefik]# cat traefik-deployment.yaml kind: DaemonSet apiVersion: extensions/v1beta1 metadata: name: traefik-ingress-controller namespace: kube-system labels: k8s-app: traefik-ingress-lb spec: 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 hostNetwork: true volumes: - name: ssl secret: secretName: traefik-cert - name: config configMap: name: traefik-conf containers: - image: traefik name: traefik-ingress-lb volumeMounts: - mountPath: "/etc/kubernetes/ssl" name: "ssl" - mountPath: "/config" name: "config" resources: limits: cpu: 200m memory: 300Mi requests: cpu: 100m memory: 200Mi ports: - name: http containerPort: 80 hostPort: 80 - name: https containerPort: 443 hostPort: 443 - name: admin containerPort: 8080 hostPort: 8080 args: - --api - --kubernetes - --configfile=/config/traefik.toml - --insecureskipverify nodeSelector: edgenode: "true" #指定部署traefik的主机标签 --- kind: Service apiVersion: v1 metadata: name: traefik-ingress-service namespace: kube-system spec: selector: k8s-app: traefik-ingress-lb ports: - protocol: TCP port: 80 name: web - protocol: TCP port: 443 name: https - protocol: TCP port: 8080 name: admin --- apiVersion: extensions/v1beta1 kind: Ingress metadata: name: traefik-web-ui namespace: kube-system spec: rules: - host: traefikui.test.com http: paths: - path: / backend: serviceName: traefik-ingress-service servicePort: admin
volumes用来引用创建的secret和configmap,volumeMounts 指定将引用的secret和configmap挂载到什么位置。
5.5.3 检查创建的traefik ui
[root@node-01 traefik]# kubectl get pods -A |grep trae kube-system traefik-ingress-controller-6q7hx 1/1 Running 0 14h kube-system traefik-ingress-controller-wgr7d 1/1 Running 0 14h
查看日志,检查有无报错
[root@node-01 traefik]# kubectl logs -f traefik-ingress-controller-wgr7d -n kube-system
测试traefik ui能否正常访问:
通过本地host测试, 172.19.8.115 traefikui.test.com , 访问 http://traefikui.test.com 和 https://traefikui.test.com
6 实战小测
1、client --- (via https) ---> traefik ---- (via http) ----> services
[root@node-01 testnginx]# cat test-nginx.yaml apiVersion: extensions/v1beta1 kind: Deployment metadata: name: my-nginx spec: replicas: 1 template: metadata: labels: app: my-nginx spec: containers: - name: my-nginx image: nginx ports: - containerPort: 443 --- apiVersion: v1 kind: Service metadata: name: my-nginx labels: app: my-nginx spec: ports: - port: 80 protocol: TCP selector: app: my-nginx --- apiVersion: extensions/v1beta1 kind: Ingress metadata: name: my-nginx spec: rules: - host: test.test.com http: paths: - backend: serviceName: my-nginx servicePort: 80 path: / tls: - hosts: - test.test.com
2、client --- (via https) ---> traefik ---- (via https) ----> services
此处使用k8s dashboard测试,因为dashboard里面只开启了443端口
假设dashboard已部署完成。此处只需添加ingress文件即可。
[root@node-01 ~]# cat kubernetes-dashboard-ingress.yaml apiVersion: extensions/v1beta1 kind: Ingress metadata: name: kube-ui namespace: kube-system spec: rules: - host: k8sui.ptengine.jp http: paths: - path: '/' backend: serviceName: kubernetes-dashboard servicePort: 443
测试完成。
此处需要注意traefik开启 --insecureskipverify 否则会出现403报错。