Kubernetes 1.18部署 Traefik2.0
参考资料：
- Traefik 2.0 官方文档：https://doc.traefik.io/traefik/v2.0/
- Kubernetes 1.18.3 部署 Traefik2.0：https://www.cnblogs.com/heian99/p/14608414.html
1. Traefik 介绍
traefik 是一款反向代理、负载均衡服务，使用 golang 实现的。和 nginx 最大的不同是，它支持自动化更新反向代理和负载均衡配置。在微服务架构越来越流行的今天，一个业务恨不得有好几个数据库、后台服务和 webapp，开发团队拥有一款 “智能” 的反向代理服务，为他们简化服务配置。traefik 就是为了解决这个问题而诞生的。
2.部署 Traefik 2.0
我的K8S环境信息如下：
[root@k8s-master ~]# kubectl get node -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
k8s-master Ready master 5d21h v1.18.0 192.168.0.51 <none> CentOS Linux 7 (Core) 3.10.0-1160.71.1.el7.x86_64 docker://20.10.6
k8s-node1 Ready <none> 5d21h v1.18.0 192.168.0.52 <none> CentOS Linux 7 (Core) 3.10.0-1160.71.1.el7.x86_64 docker://20.10.6
k8s-node2 Ready <none> 5d21h v1.18.0 192.168.0.53 <none> CentOS Linux 7 (Core) 3.10.0-1160.71.1.el7.x86_64 docker://20.10.6
2.1 创建命名空间
kubectl create ns ingress-traefik
2.2 创建CRD资源
Traefik 2.0版本后开始使用CRD来对资源进行管理配置，所以我们需要先创建CRD资源。
traefik-crd.yaml:
## IngressRoute
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: ingressroutes.traefik.containo.us
spec:
scope: Namespaced
group: traefik.containo.us
version: v1alpha1
names:
kind: IngressRoute
plural: ingressroutes
singular: ingressroute
---
## IngressRouteTCP
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: ingressroutetcps.traefik.containo.us
spec:
scope: Namespaced
group: traefik.containo.us
version: v1alpha1
names:
kind: IngressRouteTCP
plural: ingressroutetcps
singular: ingressroutetcp
---
## Middleware
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: middlewares.traefik.containo.us
spec:
scope: Namespaced
group: traefik.containo.us
version: v1alpha1
names:
kind: Middleware
plural: middlewares
singular: middleware
---
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: tlsoptions.traefik.containo.us
spec:
scope: Namespaced
group: traefik.containo.us
version: v1alpha1
names:
kind: TLSOption
plural: tlsoptions
singular: tlsoption
---
## TraefikService
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: traefikservices.traefik.containo.us
spec:
scope: Namespaced
group: traefik.containo.us
version: v1alpha1
names:
kind: TraefikService
plural: traefikservices
singular: traefikservice
---
## TraefikTLSStore
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: tlsstores.traefik.containo.us
spec:
scope: Namespaced
group: traefik.containo.us
version: v1alpha1
names:
kind: TLSStore
plural: tlsstores
singular: tlsstore
---
## IngressRouteUDP
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: ingressrouteudps.traefik.containo.us
spec:
scope: Namespaced
group: traefik.containo.us
version: v1alpha1
names:
kind: IngressRouteUDP
plural: ingressrouteudps
singular: ingressrouteudp
部署 CRD 资源:
kubectl apply -f traefik-crd.yaml
2.3 创建 RBAC 权限
Kubernetes 在 1.6 以后的版本中引入了基于角色的访问控制（RBAC）策略，方便对 Kubernetes 资源和 API 进行细粒度控制。Traefik 需要一定的权限，所以这里提前创建好 Traefik ServiceAccount 并分配一定的权限。
traefik-rbac.yaml：
apiVersion: v1
kind: ServiceAccount
metadata:
namespace: ingress-traefik
name: traefik-ingress-controller
---
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"]
- apiGroups: ["extensions"]
resources: ["ingresses/status"]
verbs: ["update"]
- apiGroups: ["traefik.containo.us"]
resources: ["middlewares"]
verbs: ["get","list","watch"]
- apiGroups: ["traefik.containo.us"]
resources: ["ingressroutes","traefikservices"]
verbs: ["get","list","watch"]
- apiGroups: ["traefik.containo.us"]
resources: ["ingressroutetcps","ingressrouteudps"]
verbs: ["get","list","watch"]
- apiGroups: ["traefik.containo.us"]
resources: ["tlsoptions","tlsstores"]
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
部署 Traefik RBAC 资源:
kubectl apply -f traefik-rbac.yaml
2.4 创建 Traefik 配置文件
由于 Traefik 配置很多，使用 CLI 定义操作过于繁琐，尽量使用将其配置选项放到配置文件中，然后存入 ConfigMap，将其挂入 traefik 中。
traefik-config.yaml:
kind: ConfigMap
apiVersion: v1
metadata:
name: traefik-config
namespace: ingress-traefik
data:
traefik.yaml: |-
serversTransport:
insecureSkipVerify: true
api:
insecure: true
dashboard: true
debug: true
metrics:
prometheus: ""
entryPoints:
web:
address: ":80"
websecure:
address: ":443"
providers:
kubernetesCRD: ""
kubernetesingress: ""
log:
filePath: ""
level: error
format: json
accessLog:
filePath: ""
format: json
bufferingSize: 0
filters:
retryAttempts: true
minDuration: 20
fields:
defaultMode: keep
names:
ClientUsername: drop
headers:
defaultMode: keep
names:
User-Agent: redact
Authorization: drop
Content-Type: keep
部署 Traefik ConfigMap 资源:
kubectl apply -f traefik-config.yaml -n ingress-traefik
2.5 设置Label标签
由于使用的Kubernetes DeamonSet方式部署Traefik，所以需要提前给节点设置Label，当程序部署Pod会自动调度到设置 Label的node节点上。
节点设置 Label 标签:
kubectl label nodes k8s-node1 IngressProxy=true
验证是否成功
[root@k8s-master Traefik2.0]# kubectl get node --show-labels
NAME STATUS ROLES AGE VERSION LABELS
k8s-master Ready master 2d20h v1.18.0 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-master,kubernetes.io/os=linux,node-role.kubernetes.io/master=
k8s-node1 Ready <none> 2d20h v1.18.0 IngressProxy=true,beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node1,kubernetes.io/os=linux
k8s-node2 Ready <none> 2d20h v1.18.0 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node2,kubernetes.io/os=linux
2.6 Kubernetes 部署 Traefik
使用DaemonSet类型部署，以便于在多服务器间扩展，使用 hostport 方式占用服务器 80、443 端口，方便流量进入。
traefik-deploy.yaml:
apiVersion: v1
kind: Service
metadata:
name: traefik
namespace: ingress-traefik
spec:
ports:
- name: web
port: 80
- name: websecure
port: 443
- name: admin
port: 8080
selector:
app: traefik
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: traefik-ingress-controller
namespace: ingress-traefik
labels:
app: traefik
spec:
selector:
matchLabels:
app: traefik
template:
metadata:
name: traefik
labels:
app: traefik
spec:
serviceAccountName: traefik-ingress-controller
terminationGracePeriodSeconds: 1
containers:
- image: traefik:2.2.0
name: traefik-ingress-lb
ports:
- name: web
containerPort: 80
hostPort: 80 #hostPort方式，将端口暴露到集群节点
- name: websecure
containerPort: 443
hostPort: 443 #hostPort方式，将端口暴露到集群节点
- name: admin
containerPort: 8080
resources:
limits:
cpu: 2000m
memory: 1024Mi
requests:
cpu: 1000m
memory: 1024Mi
securityContext:
capabilities:
drop:
- ALL
add:
- NET_BIND_SERVICE
args:
- --configfile=/config/traefik.yaml
volumeMounts:
- mountPath: "/config"
name: "config"
volumes:
- name: config
configMap:
name: traefik-config
tolerations: #设置容忍所有污点，防止节点被设置污点
- operator: "Exists"
nodeSelector: #设置node筛选器，在特定label的节点上启动
IngressProxy: "true"
部署 Traefik:
kubectl apply -f traefik-deploy.yaml
3.Traefik 路由规则基础配置
配置 HTTP 路由规则 （Traefik Dashboard 为例）
Traefik 应用已经部署完成，但是想让外部访问 Kubernetes 内部服务，还需要配置路由规则，这里开启了 Traefik Dashboard 配置，所以首先配置 Traefik Dashboard 看板的路由规则，使外部能够访问 Traefik Dashboard。
traefik-dashboard-route.yaml:
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
name: traefik-dashboard-route
namespace: ingress-traefik
spec:
entryPoints:
- web
routes:
- match: Host(`traefik.test.com`)
kind: Rule
services:
- name: traefik
port: 8080
部署Traefik Dashboard 路由规则对象:
kubectl apply -f traefik-dashboard-route.yaml
查看路由规则：
[root@k8s-master ~]# kubectl get IngressRoute -n ingress-traefik
NAME AGE
traefik-dashboard-route 2d20h
在客户端或者dns设置域名解析，ip为traefik-ingress-controller容器所在的节点IP：
192.168.0.52 traefik.example.cn
浏览器访问http://traefik.example.cn/ 打开Traefik Dashboard：
说明：
traefik-ingress-controller使用hostport方式创建，可以使用iptables查看转发规则，netstat无法查询到监听80端口：
[root@k8s-node1 ~]# iptables -S -t nat | grep :80
-A CNI-DN-f9438f6c8e00bbdb80acd -p tcp -m tcp --dport 80 -j DNAT --to-destination 10.244.1.65:80
-A KUBE-SEP-JUKVSVUESZJEP7XL -p tcp -m comment --comment "ingress-traefik/traefik:admin" -m tcp -j DNAT --to-destination 10.244.1.65:8080
-A KUBE-SEP-L5OLP67V7NUHNITG -p tcp -m comment --comment "ingress-traefik/traefik:web" -m tcp -j DNAT --to-destination 10.244.1.65:80
4. 配置 HTTPS 路由规则
使用Kubernetes 的 Dashboard测试，基于 https 协议方式访问，配置 https 的路由规则并指定证书。
关于dashboard部署方法，可以参考我的另外一篇文章《kubernetes部署dashboard》，部署后的资源信息如下：
[root@k8s-master ~]# kubectl get all -n kubernetes-dashboard
NAME READY STATUS RESTARTS AGE
pod/dashboard-metrics-scraper-7b59f7d4df-fw8zm 1/1 Running 4 3h26m
pod/kubernetes-dashboard-74d688b6bc-2jp9p 1/1 Running 12 3h26m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/dashboard-metrics-scraper ClusterIP 10.96.236.156 <none> 8000/TCP 3h26m
service/kubernetes-dashboard NodePort 10.110.146.86 <none> 443:30372/TCP 3h26m
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/dashboard-metrics-scraper 1/1 1 1 3h26m
deployment.apps/kubernetes-dashboard 1/1 1 1 3h26m
NAME DESIRED CURRENT READY AGE
replicaset.apps/dashboard-metrics-scraper-7b59f7d4df 1 1 1 3h26m
replicaset.apps/kubernetes-dashboard-74d688b6bc 1 1 1 3h26m
测试域名：kubernetes-dashboard.test.com
说明
客户端hosts文件解析如下，域名指向ingress-traefik-controller所在的节点ip：
192.168.0.52 traefik.test.com
192.168.0.52 kubernetes-dashboard.test.com
创建证书文件：
# 创建自签名证书
openssl req -x509 -nodes -days 3650 -newkey rsa:2048 -keyout tls.key -out tls.crt -subj "/CN=kubernetes-dashboard.test.com"
# 将证书存储到Kubernetes Secret中，新建的k8dash-sa-tls必须与k8dash-route中的tls: secretName一致。
kubectl create secret tls k8dash-sa-tls --key=tls.key --cert=tls.crt -n kubernetes-dashboard
创建规则文件k8s-dashboard-route.yaml，内容如下：
[root@k8s-master Traefik2.0]# cat k8s-dashboard-route.yaml
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
name: k8dash-sa-route
namespace: kubernetes-dashboard
spec:
entryPoints:
- websecure
tls:
secretName: k8dash-sa-tls
routes:
- match: Host(`kubernetes-dashboard.test.com`)
kind: Rule
services:
- name: kubernetes-dashboard
port: 443
其中name和port根据部署的kubernetes-dashboard进行查询:
[root@k8s-master Traefik2.0]# kubectl get svc -n kubernetes-dashboard
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
dashboard-metrics-scraper ClusterIP 10.96.236.156 <none> 8000/TCP 3h24m
kubernetes-dashboard NodePort 10.110.146.86 <none> 443:30372/TCP 3h24m
打开任意浏览器输入地址：https://kubernetes-dashboard.test.com 进行访问。
