East-West-cpx-ingress-proxy.md

Load balance microservice to microservice (East-West) traffic using Citrix ADC CPX

In this example, Citrix ADC CPX (a containerized form-factor) is used to route the East-West traffic between microservices (tea-bevarage and coffee-bevarage) of a sample application (hotdrink-app). An Ingress rule is deployed to send requests for the microservice to a frontend-hotdrink microservice.

This type of deployment is called as a Service Mesh lite topology, where Citrix ADC CPX load balances the East-West microservice traffic. In this example, Citrix ADC CPX is deployed as an independent pod and not as a sidecar container proxy.

Prerequisite

Ensure that you have installed and set up a Kubernetes cluster (The following example is tested in on-prem Kubernetes cluster v1.22.1).

Perform the following:

1. Deploy Citrix ADC CPX to load balance the East-West traffic in the Kubernetes cluster and verify the installation using the following commands.

    kubectl create -f https://raw.githubusercontent.com/citrix/cloud-native-getting-started/master/beginners-guide/manifest/cpx.yaml
   
    kubectl get pods -l app=cpx-ingress
   

   

2. Deploy the hotdrink application (front-end hotdrink, tea, and coffee microservices) in the Kubernetes cluster and verify the installation.

Deploy Hotdrink beverage microservices application in team-hotdrink namespace Hotdrink beverage application has tea and coffee microserives having E-W communication enabled. Tea and Coffee beverage apps uses Citrix ADC CPX for E-W communication in ServiceMesh lite deployment. We create two service kinds for each tea and coffee services. One service will point to CPX where the FQDN of the microservice (for example, coffee) should point to the Citrix ADC CPX IP address instead of the Cluster IP of the target microservice (coffee). And another service as headless service to represent tea or coffee service. Detailed Service Mesh lite deployment using headless service is explained here

    kubectl create -f https://raw.githubusercontent.com/citrix/cloud-native-getting-started/master/beginners-guide/manifest/hotdrink-app.yaml

    kubectl get pods -l app=tea-beverage

    kubectl get pods -l app=coffee-beverage

    kubectl get pods -l app=frontend-hotdrinks

![hotdrink-app](images/hotdrink-app.PNG)

3. Deploy an Ingress rule that sends traffic for 'http://hotdrink.beverages.com' to frontend-hotdrink microservice (based on whether the user request is for tea-beverage or coffee-beverage microservice, thefrontend-hotdrink microservice routes the request to tea-beverage or coffee-beverage).

   kubectl create -f https://raw.githubusercontent.com/citrix/cloud-native-getting-started/master/beginners-guide/manifest/hotdrink-ingress.yaml
   
   kubectl get ingress
   
   kubectl get svc cpx-service
   

4. Send some traffic to the frontend-hotdrink microservice.

    curl -s -H "Host: hotdrink.beverages.com " http://<MasterNode IP:<NodePort> | grep hotdrink
   

   

5. Validate the East-West traffic communication flow by performing the following steps.

   1. Edit the host file on your local machine and add DNS entries for accessing microservices though Internet and save the file.

         <K8s cluster MasterNode IP> hotdrink.beverages.com
      

      Note: Following are the path to host files depending on your operating system:

      • For Windows: C:\Windows\System32\drivers\etc\hosts
      • For Mac: /etc/hosts

   2. In a local machine, access the following URL from your browser.

       http://hotdrink.beverages.com:<NodePort>
      

      

      Note: If you are unable to view the front-end hotdrink microservice app (due to any firewall settings), access the URL from the Kubernetes cluster host machine.

   3. Click TEA image and you can see that you are redirected to the tea microservice. The front-end hotdrink microservice has called the tea microservice).

   4. Check the hit count for front-end hotdrink, and tea microservices.

       kubectl get pods -l app=cpx-ingress
      
       kubectl exec -it cpx-ingress-9f56bcbd6-9mx2z bash
      
       cli_script.sh "sh cs vserver"
      
       cli_script.sh "sh cs vserver k8s-10.244.1.120_80_http"
      

      

6. (Optional) Clean up the deployments using the following commands.

        kubectl delete -f https://raw.githubusercontent.com/citrix/cloud-native-getting-started/master/beginners-guide/manifest/cpx.yaml
        
        kubectl delete -f https://raw.githubusercontent.com/citrix/cloud-native-getting-started/master/beginners-guide/manifest/hotdrink-app.yaml
        
        kubectl delete -f https://raw.githubusercontent.com/citrix/cloud-native-getting-started/master/beginners-guide/manifest/hotdrink-ingress.yaml
   

For more information on the Citrix ingress controller, see the Citrix ingress controller documentation.

For more tutorials, see beginners-guides.