To get started, it's necessary to create your cluster on Google Cloud. Once you get your cluster created, we can now create our html page that will be our "application".

Creating and Pushing the docker image

Let's create a HTML page and publish it to a docker image.

mkdir simple-app
cd simple-app
touch index.html
vim index.html

The Dockerfile would be something really simple, for example:

FROM nginx:alpine
COPY . /usr/share/nginx/html

The docker image should be in a Docker Registry.

Using helm

If you never used helm, it helps you deploy and manage your kubernetes applications. In this tutorial, helm will be used to kick start our kubernetes deployment.

You should install helm first.

helm create simple-app

This will create all the files from helm.

  .
  ├── Chart.yaml
  ├── charts
  ├── templates
  │   ├── NOTES.txt
  │   ├── _helpers.tpl
  │   ├── deployment.yaml
  │   ├── ingress.yaml
  │   ├── service.yaml
  │   └── tests
  │       └── test-connection.yaml
  └── values.yaml

Let’s open the file values.yaml. We need to point the repository to our container registry URL, and also the tag.

image:
  repository: <YOUR CONTAINER REGISTRY GOES HERE>
  tag: <YOUR TAG GOES HERE>
  pullPolicy:IfNotPresent

In the same file, let’s change the service that comes to be a LoadBalancer and set this to the port 80.

service:
  type:LoadBalancer
  port:80

This will make helm create our external load balancer, and it automatically links it to our application. That's all, the application can be deployed.

helm install ./simple-app

The helm install command creates the external load balancer and setup our application in the cluster.

Once it is deployed, it is possible to run kubectl get services and see that the load balancer is there.

Updating the application

In case you want to update the application, for example, if you want to change the content of our HTML page. You can use the helm upgrade command.

To do it, you need to push a new tag of your container, and run:

  helm upgrade ./simple-app

And helm handles everything for you!

Today we saw how to use helm to deploy a kubernetes application, and how to update it. In this example, just a simple HTML page was used, it was intentional just to show how easy a deploy with kubernetes can be.