Host Wordpress site on Google Cloud using Kubernetes.

The purpose of this guide is a step-by-step explanation of how to create an enterprise grade, scalable, Wordpress website on google cloud. I will explain how to configure and host the site as well as how to scale the node count when needed.

Pre-requisites

Sign up for the free trail of google cloud here

Initialize a Kubernetes cluster:

• go to your cloud dashboard, search for Kubernetes Clusters
• click Create Cluster and follow the defaults.

Once created, open a Google Cloud shell by going back to your Kubernetes Clusters page, Open your newly created cluster, and click Connect.

You are ready to go!

Notes

Credit to groovemonkey for some of his explanations on GC specific kubernetes deployments.

Check out the Wordpress docker documentation here

Pay attention to:

• environment variables that the container uses (INPUT)
• which processes run inside the container
• service ports that are exposed by the container (OUTPUT)

Infrastructure Diagram:

On the left is a traditional diagram for this 3-tier web application. On the right, you see how each part of that infrastructure maps to kubernetes concepts.

Don't worry if this doesn't make sense at the beginning.

Some config data            (k8s ConfigMaps and Secrets)

MySQL Container             (k8s replicaset)
MySQL Service               (k8s service)
    |
    |
WordPress Container         (k8s deployment)
[ apache and php-fpm ]
    |
    |
DO Loadbalancer             (k8s service)

0. Pull config files

pull config files from this repository.

git clone "https://github.com/chsclarke/WordpressOnCloud.git"

1. Mysql Setup

Create an all-in-one secret for sql server:

kubectl create secret generic wp-db-secrets --from-literal=MYSQL_ROOT_PASSWORD="someComplexPassword"

save this password. you will need it to log into the sql server.

Create your mysql volume and replicaset. Expose this new internal service.

kubectl apply -f manifests/mysql-volume-claim.yaml
kubectl apply -f manifests/mysql-replicaset.yaml
kubectl apply -f manifests/mysql-service.yaml

Get a shell inside the mysql container, log into mysql, and set up the DB:

kubectl get pods
kubectl exec -it mysql-abcde -- bash    # replace mysql-abcde with the actual pod name

# use the sql root password you created earlier
mysql -u root -p

# In your mysql shell:
CREATE DATABASE wordpress;

Ctrl-c, Ctrl-d to get back out.

Check out what we just created!

kubectl get pv
kubectl get secrets
kubectl get replicasets
kubectl get pods
kubectl describe pod $YOURPOD
kubectl logs $YOURPOD

2. Wordpress Setup

Edit the config file at configs/apache.conf if you want to use a domain name for your WordPress site.

# If you were putting a custom apache config file on your containers, this is the pattern
# you would use:
# kubectl create cm --from-file configs/apache.conf apache-config

kubectl apply -f manifests/wordpress-datavolume-claim.yaml
kubectl apply -f manifests/wordpress-deployment.yaml

Check out the pattern for getting a single config file into a container in wordpress-deployment.yaml. This is currently the best practice. Yuck!

3. Load Balancer Setup

It's just exposing our app to the Internet, not really load-balancing (because we're running a stateful singleton).

kubectl apply -f manifests/DO-loadbalancer.yaml

View your work!

Grab the load balancer's external IP here:

kubectl get services

You can also see this in your DO dashboard: Networking --> Load Balancers.

Paste the IP address under (wordpress-lb,EXTERNAL-IP) into your browser and you will see your Wordpress site!

If your website is using too many resources, scale it down to 0 to stop paying:

kubectl scale deployment wordpress --replicas=0

To scale the website up to handle increased traffic, scale it up as much as you want:

kubectl scale deployment wordpress --replicas=AS_MUCH_AS_YOU_NEED

Cleanup

To delete everything and start over, go into your DO dashboard and:

1. Delete the kubernetes cluster
2. Networking --> Load Balancers --> LB Settings --> Delete
3. Volumes --> Delete your volumes

Restarting from a blank slate:

See ~/02-digitalocean-setup.md, or:

1. In your DO dashboard, create a new 'tl-testcluster' kubernetes cluster
2. Download the cluster config file (scroll down)
3. mv ~/Downloads/tl-testcluster-kubeconfig.yaml ~/.kube/config
4. Once kubectl get nodes shows your nodes as READY (~5min), continue with the next step.
5. cd digitalocean-cloud-controller-manager
6. kubectl apply -f releases/secret.yml
7. kubectl apply -f releases/v0.1.8.yml
8. cd $THIS_PROJECT/projects/wordpress/
9. Start with the MySQL Setup section at the beginning of this document