Helm is the package manager for Kubernetes, it enables us to configure and deploy various Kubernetes resources using Helm Charts. Below are a few examples of charts that you can use to install applications into Kubernetes.
Let's deploy the wordpress Helm Chart. First let's see what resources get deployed.
helm repo add bitnami https://charts.bitnami.com/bitnami
helm install wordpress --create-namespace --dry-run -n wordpress bitnami/wordpressThis should print out all the resources this chart will create, followed by the instruction on how to access the wordpress installation once the deployment is done.
Let's deploy the Chart.
helm install wordpress --create-namespace -n wordpress bitnami/wordpressOnce you have inspected the installed resources you can delete the installation by running the following command.
helm delete wordpress -n wordpress
kubectl delete ns wordpressWe can also use Helm charts to define our own applications so can we dynamically apply configuration and deploy our applications.
Go through the following sections of the Chart Template Guide at the Helm docs:
- Getting Started
- Built-in Objects
- Values Files
- Template Functions and Pipelines
- Flow Control
- Variables
- Debugging Templates
We will spend the rest of this lab trying to deploy a sample application to Kubernetes using Helm and Azure DevOps. The idea is that you deploy the application to a test environment and then on to a production environment.
These environments need to to have their own resources and should be configured seperately.
The sample application to deploy can be found here. By modifying an environment variable called WelcomeMessage, you can change the welcome message displayed at the website.