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Setting up HTTP Load Balancing with Ingress

Create a backend service

Create a simple web services, analogous to those encountered in the previous chapter but of type NodePort, that are listening on a HTTP server on port 80. When you create a Service of type NodePort, Kubernetes makes your Service available on a randomly selected high port number (in the range 30000-32767) on all the nodes in your cluster.

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$ kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
coffee-svc   NodePort    10.110.66.194   <none>        80:31156/TCP   3d1h
tea-svc      NodePort    10.96.32.111    <none>        80:30458/TCP   3d1h
# Verify that the service is working
$ curl 10.110.66.194
Server address: 172.16.231.221:8080
Server name: coffee-6f4b79b975-v7cv2
Date: 30/Oct/2020:16:33:20 +0000
URI: /
Request ID: 8d870888961431bf04dd2305d614004f

Create an Ingress resource

Now we create an Ingress resource, to make your HTTP web server application publicly accessible. The following command defines an Ingress resource that forwards traffic that requests http://webserver-bar.com to the webserver

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: lb
  annotations:
    kubernetes.io/ingress.class: "openstack"
    octavia.ingress.kubernetes.io/internal: "false"	# Set true, if you don't want your Ingress to be accessible from the public internet
spec:
  rules:
  - host: webserver-bar.com
    http:
      paths:
      - path: /tea
        pathType: Prefix
        backend:
          service:
            name: tea-svc
            port:
              number: 80
      - path: /coffee
        pathType: Prefix
        backend:
          service:
            name: coffee-svc
            port:
              number: 80

Verify that Ingress Resource has been created. Please note that the IP address will not be defined right away (wait for the ADDRESS field to get populated). It is possible to follow the implementation of the LoadBalancer LB step by step, from the creation of its components (Listener, Pool, Policy) to the assignment of the FIP, from the log of the Pod of the Ingress Controller (the whole operation can take a few minutes).

$ kubectl get ing
NAME   CLASS    HOSTS               ADDRESS          PORTS   AGE
lb     <none>   webserver-bar.com   131.154.97.200   80      3d1h

Go to OpenStack and check that the LB has been created in the Project/Network/LoadBalancer tab.