Umbrella Helm Chart for deploying apps to AKS

This helm chart can be used to easily deploy apps to your AKS cluster configured with Pod Identity, an Application Gateway and an Azure Key Vault where pods can directly read secrets from.

This chart is heavily dependent on these resources and builds upon the Fully Configured AKS Terraform Deployment repostitory that deploys these to Azure.

Prequisites:

• helm v3
• azure-cli
• Fully configured AKS deployement

Overview

This repo provides two helm charts:

• /helm-app/ - umbrella helm chart available on Docker Hub
• /helm-app-example/ - app helm chart built on the umbrella helm chart above (as a Chart dependency)

The umbrella helm-app Chart provides these templates:

• deployment.yaml - AKS deployment with the Container Pod
• ingress.yaml - Ingress with all redirect rule (automatically applied to AppGateway)
• kedascalarr.yaml - ScaledObject that allows KEDA to horizontally scale when enabled
• secretproviderclass.yaml - SecretProviderClass that fetches secrets from Azure Key Vault and exposes them to other pods through podidentity
• service.yaml - The service that hosts the app deployment.yaml

Configuration

An example of all configuration parameters and its default values is shown in (./helm-app/values.yaml)[helm-app/values.yaml]. When you use this umbrella helm chart as a dependency, you only have to define the parameters you want to change. Leaving parameters out will automatically set them to their default values.

Config - App

Name	Description	Default
name	App name	app-service-name
aadpodidbinding	Name of your Azure AD Pod Identity binding1	podidentity
replicaCount	Amount of replicas you want for your pod	1
secretEnv (list)	List of Environment Variables fetched from Azure Key Vault	[]
- envName	Environment variable name
- secretKey	Secret name from Azure Key Vault
env (list)	Kubernetes version of the node pool	[]
- key	Environment variable name
- value	Value of environment variable
container (object)	Container object	{}
- image	Container image that runs inside the pod	ghcr.io/your-username/your-repo:your-tag
- port	Container port the image is hosted on	80
- healthCheckHttpGetPath	Path for Application Gateway to check for a healthy endpoint2	/

¹ Equals podidentity binding if you didn't change the default values in the terraform deployment
² Healthy HTTP StatusCode required, between 200 and 399

Config - Ingress

Name	Description	Default
name	Name of your ingress	app-ingress-name
replicaCount	Amount of replicas you want for your ingress	1
dnsName	DNS Name of your Application Gateway Public IP (without https())
paths (list)	List of ingress paths	[]
- path	Path where pod is hosted	/*
- backend: serviceName	Name of the service defined in app	app-service-name
- backend: servicePort	Port where container is hosted	80

Config - SecretStore

Name	Description	Default
provider	Name of your SecretStore provider	azure
usePodIdentity	Boolean to trigger use of Pod Identity	true
keyvaultName	Name of the Azure Key Vault to fetch secrets from	yourkeyvaultname
secrets (array)	List of secrets to fetch (e.g. ["secret1", "secret2"])	[]
tenantId	TenantID of your Azure tenant	00000000-0000-0000-0000-000000000000

Config - Helm

Name	Description	Default
enabled	Boolean to enable KEDA	false
name	Name of your KEDA ScaledObject	app-service-name-keda
authRefName	Name of the TriggerAuthentication connected to KEDA	auth-trigger-app-service-name
scaleTargetRef	Name of the k8s service you would like to scale up/down	app-service-name
minReplicaCount	Minimum pod replica count for your scalable service	1
minReplicaCount	Maximum pod replica count for your scalable service	10
triggers (list)	List of KEDA scalars	[]
- type	Type of KEDA scalar	azure-servicebus
- metadata (object)	Object with KEDA trigger-type specific values for scaling	{}

Usage

1. Clone repo

git clone https://github.com/bart-jansen/secretstore-ingress-apps-helm.git

2. cd into /helm-app-example and make appropriate changes to Chart.yaml and values.yaml

3. Login to your AKS cluster (if you haven't already):

az aks get-credentials -n youraksclustername -g yourresourcegroupname

4. Install Helm Chart:

helm upgrade --install --namespace aksnamespace -f values.yaml your-app-name .