K8S-Ingress-Controller

service是将一组pod管理起来，提供了一个cluster ip和service name的统一访问入口，屏蔽了pod的ip变化。
ingress 是一种基于七层的流量转发策略，即将符合条件的域名或者location流量转发到特定的service上，而ingress仅仅是一种规则，k8s内部并没有自带代理程序完成这种规则转发。
ingress-controller 是一个代理服务器，将ingress的规则能真正实现的方式，常用的有 nginx,traefik,haproxy。但是在k8s集群中，建议使用traefik，性能比haroxy强大，更新配置不需要重载服务，是首选的ingress-controller。
github地址：https://github.com/containous/traefik

一、准备traefik镜像

#准备镜像
[root@hdss1-55 ~]# cd /data/k8s-yaml/
[root@hdss1-55 k8s-yaml]# mkdir traefik
[root@hdss1-55 k8s-yaml]# cd traefik/
[root@hdss1-55 traefik]# docker pull traefik:v1.7.2-alpine
v1.7.2-alpine: Pulling from library/traefik
4fe2ade4980c: Pull complete 
8d9593d002f4: Pull complete 
5d09ab10efbd: Pull complete 
37b796c58adc: Pull complete 
Digest: sha256:cf30141936f73599e1a46355592d08c88d74bd291f05104fe11a8bcce447c044
Status: Downloaded newer image for traefik:v1.7.2-alpine
docker.io/library/traefik:v1.7.2-alpine
#将奖项push到仓库里
[root@hdss1-55 traefik]# docker images|grep traefik
traefik                         v1.7.2-alpine                   add5fac61ae5        2 years ago         72.4MB
[root@hdss1-55 traefik]# docker tag add5fac61ae5 harbor.od.com/public/traefik:v1.7.2
[root@hdss1-55 traefik]# docker push harbor.od.com/public/traefik:v1.7.2
The push refers to repository [harbor.od.com/public/traefik]
a02beb48577f: Pushed 
ca22117205f4: Pushed 
3563c211d861: Pushed 
df64d3292fd6: Pushed 
v1.7.2: digest: sha256:6115155b261707b642341b065cd3fac2b546559ba035d0262650b3b3bbdd10ea size: 1157

二、准备资源配置清单

root@hdss1-55 traefik]# ls
ds.yaml  ingress.yaml  rbac.yaml  svc.yaml
[root@hdss1-55 traefik]# cat ds.yaml 
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: traefik-ingress
  namespace: kube-system
  labels:
    k8s-app: traefik-ingress
spec:
  template:
    metadata:
      labels:
        k8s-app: traefik-ingress
        name: traefik-ingress
    spec:
      serviceAccountName: traefik-ingress-controller
      terminationGracePeriodSeconds: 60
      containers:
      - image: harbor.od.com/public/traefik:v1.7.2
        name: traefik-ingress
        ports:
        - name: controller
          containerPort: 80
          hostPort: 81
        - name: admin-web
          containerPort: 8080
        securityContext:
          capabilities:
            drop:
            - ALL
            add:
            - NET_BIND_SERVICE
        args:
        - --api
        - --kubernetes
        - --logLevel=INFO
        - --insecureskipverify=true
        - --kubernetes.endpoint=https://172.16.1.60:7443
        - --accesslog
        - --accesslog.filepath=/var/log/traefik_access.log
        - --traefiklog
        - --traefiklog.filepath=/var/log/traefik.log
        - --metrics.prometheus
[root@hdss1-55 traefik]# cat ingress.yaml 
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: traefik-web-ui
  namespace: kube-system
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: traefik.od.com
    http:
      paths:
      - path: /
        backend:
          serviceName: traefik-ingress-service
          servicePort: 8080
[root@hdss1-55 traefik]# cat rbac.yaml 
apiVersion: v1
kind: ServiceAccount
metadata:
  name: traefik-ingress-controller
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
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: kube-system
[root@hdss1-55 traefik]# cat svc.yaml 
kind: Service
apiVersion: v1
metadata:
  name: traefik-ingress-service
  namespace: kube-system
spec:
  selector:
    k8s-app: traefik-ingress
  ports:
    - protocol: TCP
      port: 80
      name: controller
    - protocol: TCP
      port: 8080
      name: admin-web

三、依次执行创建

在172.16.1.54上执行
[root@hdss1-54 ~]# kubectl apply -f http://k8s-yaml.od.com/traefik/rbac.yaml
serviceaccount/traefik-ingress-controller created
clusterrole.rbac.authorization.k8s.io/traefik-ingress-controller created
clusterrolebinding.rbac.authorization.k8s.io/traefik-ingress-controller created
[root@hdss1-54 ~]# kubectl apply -f http://k8s-yaml.od.com/traefik/ds.yaml
daemonset.extensions/traefik-ingress created
[root@hdss1-54 ~]# kubectl apply -f http://k8s-yaml.od.com/traefik/svc.yaml
service/traefik-ingress-service created
[root@hdss1-54 ~]# kubectl apply -f http://k8s-yaml.od.com/traefik/ingress.yaml
ingress.extensions/traefik-web-ui created

四、配置反向代理

#172.16.1.51和172.16.1.52同样的配置
[root@hdss1-51 ~]# vim /etc/nginx/conf.d/od.com.conf
server {
    server_name *.od.com;
  
    location / {
        proxy_pass http://default_backend_traefik;
        proxy_set_header Host       $http_host;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
    }
}

upstream default_backend_traefik {
    # 所有的nodes都放到upstream中
    server 172.16.1.53:81    max_fails=3 fail_timeout=10s;
    server 172.16.1.54:81    max_fails=3 fail_timeout=10s;
}

[root@hdss1-51 ~]# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
[root@hdss1-51 ~]# nginx -s reload

五、配置域名解析

回滚一条记录

[root@hdss1-51 ~]# vim /var/named/od.com.zone 
$ORIGIN od.com.
$TTL 600  ; 10 minutes
@       IN SOA  dns.od.com. dnsadmin.od.com. (
        **2020101904** ; serial
        10800      ; refresh (3 hours)
        900        ; retry (15 minutes)
        604800     ; expire (1 week)
        86400      ; minimum (1 day)
        )
        NS   dns.od.com.
$TTL 60 ; 1 minute
dns                A    172.16.1.51
harbor             A    172.16.1.55
k8s-yaml           A    172.16.1.55
**traefik            A    172.16.1.60**

[root@hdss1-51 ~]# systemctl restart named