Wordpress and SQL pod on the top of K8S using ansible.

Welcome again to the another article of automation.

Today we are going to launch wordpress and sql pod over K8S multi-node cluster using Ansible.

In our last article we launched k8S cluster over AWS using Ansible.
Now lets continue further integration using ansible.

Now what we can do is create a role for automating deployment of pod over K8s cluster.

Requisites:

  1. Get epel release software and install
  2. Install python3 and python3-pip
  3. Upgrade aws cli version.

In this demonstration ,I would be using shell module of ansible to do deployment .

You can try Ansible K8S object to deploy pods over Cluster:

We will need credentials for going to instance and do configurations thus ,I have stored all credentials in ansible-vault.

In order to launch pod we need kubernetes client on our computer configured as a client.In earlier integration ,we did the needful.

Also we need WordPress image,may be you create it yourself and deploy or we have wordpress:5.1.1-php7.3-apache .

WordPress uses SQL as a database,thus we require image of that also :

mysql:5.7.

Note: Your WordPress version should be compatible with SQL version.

For more details refer documentation.

To launch pod over K8S we use:

kubectl run <podname> --image=<image_name>

Lets see how we can do this using ansible:

We have used shell module to execute the commands.

For mysql pod we required to pass environment variables:
For more info refer to this

  1. MYSQL_ROOT_PASSWORD
  2. MYSQL_DATABASE
  3. MYSQL_USER
  4. MYSQL_PASSWORD

Once we have launched the pod ,we need to expose Wordpress pod in order to access it .

We have to create service resource for this:
A Kubernetes Service is an abstraction layer which defines a logical set of Pods and enables external traffic exposure, load balancing and service discovery for those Pods.

Although each Pod has a unique IP address, those IPs are not exposed outside the cluster without a Service. Services allow your applications to receive traffic. Services can be exposed in different ways by specifying a type in the ServiceSpec:

  • ClusterIP (default) — Exposes the Service on an internal IP in the cluster. This type makes the Service only reachable from within the cluster.
  • NodePort — Exposes the Service on the same port of each selected Node in the cluster using NAT. Makes a Service accessible from outside the cluster using <NodeIP>:<NodePort>. Superset of ClusterIP.
  • LoadBalancer — Creates an external load balancer in the current cloud (if supported) and assigns a fixed, external IP to the Service. Superset of NodePort.
  • ExternalName — Maps the Service to the contents of the externalName field (e.g. foo.bar.example.com), by returning a CNAME record with its value. No proxying of any kind is set up. This type requires v1.7 or higher of kube-dns, or CoreDNS version 0.0.8 or higher.

We will be using NodePort type to expose the pod using service:

Tadaa!!! Our pod is exposed .

Now,

For this page we need DB end point,thus to get IP of Mysql pod ,we can use:

- name: "Fetching DB IP"
shell: "kubectl get pod sqldb -o wide"
register: dbip

This will help to get ip of the pod .

🎉🎉Finally,we have done our setup using Ansible over K8S …..

k8s_deploy role is available on Github .

Happy learning …..😁😁😁

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Vishugoyal

Vishugoyal

I am pursiing B-tech. and also very fond of learning new technology under the guidance of Vimal Daga sir (World Record Holder).