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Custom application

We will create a simple docker image to customize the HTML and see it running

Requirements

Dockerfile

Let’s create a Dockerfile and push it to Dockerhub.

mkdir docker
cd docker
touch Dockerfile

Open the file and add:

FROM php:7.4-apache
COPY . /var/www/html/

Create a index.php file. We want to PHP print the hostname, so we will know what host we are getting to:

touch index.php

Add the content:

<?php
echo gethostname();
?>

Building the docker image

Now you should have your dockerhub account. Let’s build. Don’t forget to substitute the <your-dockerhub-name> by your account. For example, mine is matwolbec.

docker build -t <your-dockerhub-name>/php-gethostname:v1 -f Dockerfile .

Before we can push it, let’s create the repository on DockerHub: https://hub.docker.com/repository/create. Name it php-gethostname and leave the visibility as Public.

Login on your docker-cli:

docker login

We can now push it to dockerhub:

docker push matwolbec/php-gethostname:v1

We should tag the version as the latest available:

docker tag matwolbec/php-gethostname:v1  matwolbec/php-gethostname:latest
docker push matwolbec/php-gethostname:latest
cd ..

Deploying our image to our Kubeernetes cluster

Open the deployment.yaml and change:

          image: httpd:latest

To:

          image: matwolbec/php-gethostname:latest

And apply:

kubectl apply -f deployment.yaml

You can watch the magic happening with:

kubectl get pods

Destroying

Don’t forget to destroy your resources to avoid charges.

Run:

kubectl delete -f deployment.yaml
terraform destroy

Next steps

Go to Ingress Controller.