traefik-Ingress边缘路由器落地到微服务

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.

它最大的优点是能够与常见的微服务系统直接整合，可以实现自动化动态配置。

2.以下配置文件可以在kubernetes-handbookGitHub仓库中的../manifests/traefik-ingress/目录下找到。

2.1创建ingress-rbac.yaml

将用于service account验证。

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

2.2 创建名为traefik-ingress的ingress，文件名ingress.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: traefik-ingress
namespace: default
spec:
rules:
- host: traefik.nginx.io
http:
paths:
- path: /
backend:
serviceName: my-nginx
servicePort: 80
- host: traefik.frontend.io
http:
paths:
- path: /
backend:
serviceName: frontend
servicePort: 80

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 ingress.yaml来更新。

2.3创建DaemonSet

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。

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: 8580
hostPort: 8580
args:
- --web
- --web.address=:8580
- --kubernetes
nodeSelector:
edgenode: "true"

给nodes打标签

kubectl label nodes node1 edgenode=true
kubectl label nodes node2 edgenode=true

2.4 Traefik UI

使用下面的yaml配置来创建Traefik的Web UI。

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: traefik-ui.local
http:
paths:
- path: /
backend:
serviceName: traefik-web-ui
servicePort: web

访问该地址http://node1:8580/将可以看到dashboard。

2.6在客户端修改hosts 后直接访问

10.2.1.226 traefik.nginx.io
10.2.1.226 traefik.frontend.io