Container cloud platform No.4~kubernetes service exposed Ingress

This is the fourth in a container cloud platform, then on a continuing,
first kubernetes services expose the following ways:

NodePort
Loadbalance
ClusterIP
Ingress

This article is close to the first architecture diagram, only introduces Ingress, and the rest will be described in detail later. .

What is Ingress?

Ingress is an API object that manages external access to services in the cluster. The typical access method is HTTP. Of course, TCP can also be managed.
Ingress can provide load balancing, SSL termination, and domain-based virtual hosting.
The vernacular is: Expose the services deployed by the kubernetes cluster so that users or services outside the cluster can access it.

There are many controllers that can provide ingress for kubernetes. This article uses a HAProxy-based controller: Haproxy Ingreess.
HAProxy is a fast and reliable TCP and HTTP reverse proxy and load balancer.
Of course, a kubernetes cluster can also deploy multiple ingress controllers at the same time.

HAProxy Ingress

HAProxy Ingress obtains the pod status of the services backend by monitoring the Kubernetes API, and dynamically updates the configuration file of haproxy to achieve load balancing.
It allows thousands of requests per second per agent, regardless of the size of the cluster, with very low latency.

A brief introduction, and then the actual combat.

Deploy HAProxy Ingress to kubernetes cluster

Download the yaml deployment file:wget https://haproxy-ingress.github.io/resources/haproxy-ingress.yaml
Modify haproxy-ingress.yaml, because now using the 1.19 version, and some api version has expired, you need to modify the next
rbac.authorization.k8s.io/v1beta1change rbac.authorization.k8s.io/v1, if you do not have to modify Warning, but does not affect the current

deploy:kubectl apply -f haproxy-ingress.yaml

[root@k8s-master001 opt]# kubectl  apply -f haproxy-ingress.yaml 
namespace/ingress-controller created
serviceaccount/ingress-controller created
Warning: rbac.authorization.k8s.io/v1beta1 ClusterRole is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io/v1 ClusterRole
clusterrole.rbac.authorization.k8s.io/ingress-controller created
Warning: rbac.authorization.k8s.io/v1beta1 Role is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io/v1 Role
role.rbac.authorization.k8s.io/ingress-controller created
Warning: rbac.authorization.k8s.io/v1beta1 ClusterRoleBinding is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io/v1 ClusterRoleBinding
clusterrolebinding.rbac.authorization.k8s.io/ingress-controller created
Warning: rbac.authorization.k8s.io/v1beta1 RoleBinding is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io/v1 RoleBinding
rolebinding.rbac.authorization.k8s.io/ingress-controller created
configmap/haproxy-ingress created
daemonset.apps/haproxy-ingress created

View deployment status

[root@k8s-master001 opt]# kubectl  get all -n ingress-controller
NAME                             DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR AGE
daemonset.apps/haproxy-ingress   0         0         0       0            0           role=ingress-controller   6m2s

What the hell, why is there no pod related to haproxy?
Container cloud platform No.4~kubernetes service exposed Ingress

Now look at the haproxy-ingress.yaml file and find that it defines the nodeSelector node label selector, but now the cluster node does not have any machine with this label, so you need to set a reasonable label for the node, or you will not create a pod
now manually Add a label to master003role=ingress-controller
```
[root@k8s-master001 opt]#  kubectl label node k8s-master003 role=ingress-controller
node/k8s-master003 labeled
```

Let's check again, there is already haproxy-ingress-6mfqr, the status is Running, which means it has been deployed, is it easy~~~

[root@k8s-master001 opt]# kubectl  get all -n ingress-controlle
NAME                        READY   STATUS    RESTARTS   AGE
pod/haproxy-ingress-6mfqr   1/1     Running   1          2m40s

NAME                             DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR             AGE
daemonset.apps/haproxy-ingress   1         1         1       1            1           role=ingress-controller   18m

Use Ingress to expose services

Here we use the nginx deployed in the previous article as an example, deploy the previous article, and now check the nginx status

[root@k8s-master001 ~]# kubectl  get po,svc
NAME          READY   STATUS    RESTARTS   AGE
pod/nginx-0   1/1     Running   0          32h

NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
service/kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP        2d2h
service/nginx        NodePort    10.106.27.213   <none>        80:30774/TCP   32h

You can see that there is a service named nginx

[root@k8s-master001 ~]# cat ingress.yaml 
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: nginx
  annotations:
    kubernetes.io/ingress.class: haproxy
spec:
  rules:
  - host: nginx.ieasou.cn
    http:
      paths:
       - path: /
         backend:
           serviceName: nginx
           servicePort: 80

If you execute the deployment, there will be a Warning, because the kubernetes apiVersion is updated, and extensions/v1beta1 will no longer be supported in the future. This does not affect it. Ignore it first.

[root@k8s-master001 ~]# kubectl  apply -f ingress.yaml
Warning: extensions/v1beta1 Ingress is deprecated in v1.14+, unavailable in v1.22+; use networking.k8s.io/v1 Ingress
ingress.extensions/nginx configured

View deployment results

[root@k8s-master001 ~]# kubectl  get ing 
NAME    CLASS    HOSTS             ADDRESS   PORTS   AGE
nginx   <none>   nginx.test.cn             80      21m

Now, you need to resolve nginx.test.cn to the IP of the node where haproxy-ingresss is located. In this article, if haproxy-ingresss is deployed to master003 (10.26.25.22) for
testing, you can directly modify the /etc/hosts file, and then you can access nginx.test. cn

[root@k8s-master001 ~]# curl -I nginx.text.cn
HTTP/1.1 200 OK
server: nginx/1.19.2
date: Sat, 12 Sep 2020 12:40:01 GMT
content-type: text/html
content-length: 612
last-modified: Tue, 11 Aug 2020 14:50:35 GMT
etag: "5f32b03b-264"
accept-ranges: bytes
strict-transport-security: max-age=15768000

As you can see from the result, the status code is returned, indicating that the deployed nginx service can be accessed.
Container cloud platform No.4~kubernetes service exposed Ingress

Note: The pictures in the article are from the Internet. If there is any infringement, please contact me to delete it in time.
Tips: For more good articles, please pay attention to the public * "Rookie Operation and Maintenance Talk"! ! !