PACS Wordpress Kubernetes Deployment

This repository provides the details of the kubernetes deployment of a three-tier wordpress application that can be used for benchmarking several auto-scaling algorithms. This repository provides you with the yaml files needed to deploy the structure and get the kubernetes deployment up and running.

Deployment Structure

This three-tier wordpress application consists of MySql 5.6 as the database, Wordpress with PHP 7.3 FPM as the application server and Nginx 1.7.9 as the web server.

Deployment Procedure

• Before setting up the kubernetes cluster, we need an NFS server to serve the static files used by Wordpress and Nginx. All instances of our web server and application server will use this file server.

• Follow This Tutorial for setting up the NFS server. In /etc/exports, use the following as the permission for the /var/nfs/general:

(rw,sync,no_subtree_check,no_root_squash)

• Don't forget to allow NFS server access to your cluster either by setting your cluster's IP range in /etc/exports or by setting the client IP to * to allow any host to connect and limit the access to the NFS server via your firewall.

You need to open ports 111 and 2049 for both TCP and UDP for NFS to function properly.

• Note your NFS server IP address since you will have to input this into your yaml files. We will call this value NFS_SERVER_IP from now on.

• Make a copy of the wordpress yaml template:

cp ./yaml/wordpress-deployment-template.yaml ./yaml/wordpress-deployment.yaml

• For security reasons, update lines 57-64 with new values from this address.

• Upload line 137 with the IP address of your NFS server (NFS_SERVER_IP).

• In case you want to use your private docker registry for faster pulls from your cluster, first upload the Wordpress FPM docker image to your private registry using docker pull wordpress:php7.3-fpm-alpine, then docker tag wordpress:php7.3-fpm-alpine -t YOUR_PRIVATE_DOCKER_REGISTRY_ADDRESS/wordpress:php7.3-fpm-alpine and then docker push YOUR_PRIVATE_DOCKER_REGISTRY_ADDRESS/wordpress:php7.3-fpm-alpine. After doing this step, update line 179 of wordpress-deployment.yaml with YOUR_PRIVATE_DOCKER_REGISTRY_ADDRESS/wordpress:php7.3-fpm-alpine as the docker image address.

• Deploy the structure to your kubernetes cluster using Kustomization:

kubectl apply -k ./yaml/

• It should take about 5 minutes for the whole deployment to get to the Running state. To monitor the progrss, you can use kubectl get events -w, kubectl get deploy -w, or kubectl get pods -w. After the service is up and running, you can use kubectl get svc to get a list of services along the IP of the load balancer assigned to them:

NAME              TYPE           CLUSTER-IP     EXTERNAL-IP      PORT(S)          AGE
kubernetes        ClusterIP      X.X.X.X        <none>           443/TCP          14d
wordpress         ClusterIP      X.X.X.X        <none>           9000/TCP         14d
wordpress-mysql   ClusterIP      None           <none>           3306/TCP         14d
wordpress-nginx   LoadBalancer   X.X.X.X        X.X.X.X          80:32349/TCP     14d

The external IP in the EXTERNAL-IP column of the row wordpress-nginx is the IP you can use to access your wordpress setup. Open this IP address and finish the wordpress setup.

Deploying the Locust Load Tester

In case you want to use the pacs Locust Load Tester within the kubernetes cluster to test your autoscaling algorithm, you could do so by deploying our locust load tester to your cluster. This alleviates the effect of network latency and jitter in your results. Here are the steps to set this up:

• Create a copy of the template yaml file:

cp ./lt-yaml/lt-template.yaml ./lt-yaml/lt.yaml

• In lt-yaml/lt.yaml file, update the external ip to access your wordpress application on line 41 (--host=http://EXTERNAL_IP/).

• Deploy the load tester to your kubernetes cluster:

kubectl apply -f ./lt-yaml/lt.yaml

• Wait for the deployment to become available. Get the external IP for the locust server using kubectl get svc and open EXTERNAL_LOCUST_IP:8089 in your browser.

• Load test your setup with different number of users.

• In case you want to reset the locust deployment:

kubectl scale deploy/wordpress-lt --replicas=0

# Wait for the pods to be terminated
kubectl get deploy/wordpress-lt

# Create the pod again
kubectl scale deploy/wordpress-lt --replicas=1

• To fix the redirect issue

Edit your current theme's functions.php and add following line after the opening PHP tag to disable canonical redirection.

remove_filter('template_redirect','redirect_canonical'); save and exit.