Ksctl Application Controller

Documentation on ksctl application controller

Categories:

It helps in deploying applications using crd to help manage with installaztion, upgrades, downgrades, uninstallaztion. from one version to another and provide a single place of truth where to look for which applications are installed

Types

Stack

For defining a hetrogenous components we came up with a stack which contains M number of components which are different applications with their versions

Info

this is current available on all clusters created by ksctl@v1.2.0

Note

It has a dependency on ksctl agent

About Lifecycle of application stack

once you have kubectl apply the stack it will start deploying the applications in the stack, if you want to upgrade the applications in the stack you can edit the stack and change the version of the application and apply the stack again, it will uninstall the previous version and install the new version. Basically it performs reinstall of the stack which might cause downtime

Supported Apps and CNI

Name	Type	Category	Ksctl_Name	More Info
Argo-CD	standard	CI/CD	standard-argocd	Link
Argo-Rollouts	standard	CI/CD	standard-argorollouts	Link
Istio	standard	Service Mesh	standard-istio	Link
Cilium	standard	-	cilium	Link
Flannel	standard	-	flannel	Link
Kube-Prometheus	standard	Monitoring	standard-kubeprometheus	Link
SpinKube	production	Wasm	production-spinkube	Link
WasmEdge and Wasmtime	production	Wasm	production-kwasm	Link

Note on wasm category apps

Only one of the app under the category wasm can be installed at a time we you might need to uninstall one to get another running

also the current implementation of the wasm catorgoty apps annotate all the nodes with kwasm as true

Components in Stack

All the stack are a collection of components so when you are overriding the stack values you need to tell which component it belongs to and then specifiy the value in a map[string]any format

Argo-CD

How to use it (Basic Usage)

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: argocd
spec:
	stacks:
	- stackId: standard-argocd
		appType: app

Overrides available

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: argocd
spec:
	stacks:
	- stackId: standard-argocd
		appType: app
		overrides:
			argocd:
				version: <string> # version of the argocd
				noUI: <bool> # to disable the UI
				namespace: <string> # namespace to install argocd
				namespaceInstall: <bool> # to install namespace specific argocd

Argo-Rollouts

How to use it (Basic Usage)

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: argorollouts
spec:
	stacks:
	- stackId: standard-argorollouts
		appType: app

Overrides available

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: argorollouts
spec:
	stacks:
	- stackId: standard-argorollouts
		appType: app
		overrides:
			argorollouts:
				version: <string> # version of the argorollouts
				namespace: <string> # namespace to install argocd
				namespaceInstall: <bool> # to install namespace specific argocd

Istio

How to use it (Basic Usage)

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: istio
spec:
	stacks:
	- stackId: standard-istio
		appType: app

Overrides available

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: istio
spec:
	stacks:
	- stackId: standard-istio
		appType: app
		overrides:
			istio:
				version: <string> # version of the istio
				helmBaseChartOverridings: <map[string]any> # helm chart overridings, istio/base
				helmIstiodChartOverridings: <map[string]any> # helm chart overridings, istio/istiod

Cilium

Currently we cannot install via the ksctl crd as cni are needed to be installed when configuring otherwise it will cause network issues

still we have cilium can be installed and only configuration available are version, we are working towards how can we allow users to specify the overridings in the cluster creation

anyways here is how it is done

we can consider using a file spec instead of cmd parameter, until that is done you have to wait

How to use it (Basic Usage)

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: cilium
spec:
	stacks:
	- stackId: cilium
		appType: app

Overrides available

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: cilium
spec:
	stacks:
	- stackId: cilium
		appType: app
		overrides:
			cilium:
				version: <string> # version of the cilium
				ciliumChartOverridings: <map[string]any> # helm chart overridings, cilium

Flannel

Currently we cannot install via the ksctl crd as cni are needed to be installed when configuring otherwise it will cause network issues

still we have flannel can be installed and only configuration available are version, we are working towards how can we allow users to specify the overridings in the cluster creation

we can consider using a file spec instead of cmd parameter, until that is done you have to wait

How to use it (Basic Usage)

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: flannel
spec:
	stacks:
	- stackId: flannel
		appType: cni

Overrides available

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: flannel
spec:
	stacks:
	- stackId: flannel
		appType: cni
		overrides:
			flannel:
				version: <string> # version of the flannel

Kube-Prometheus

How to use it (Basic Usage)

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: monitoring
spec:
	stacks:
	- stackId: standard-kubeprometheus
		appType: app

Overrides available

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: monitoring
spec:
	stacks:
	- stackId: standard-kubeprometheus
		appType: app
		overrides:
			kube-prometheus:
				version: <string> # version of the kube-prometheus
				helmKubePromChartOverridings: <map[string]any> # helm chart overridings, kube-prometheus

SpinKube

How to use it (Basic Usage)

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: wasm-spinkube
spec:
	stacks:
	- stackId: production-spinkube
		appType: app

Demo app

kubectl apply -f https://raw.githubusercontent.com/spinkube/spin-operator/main/config/samples/simple.yaml
kubectl port-forward svc/simple-spinapp 8083:80
curl localhost:8083/hello

Overrides available

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: wasm-spinkube
spec:
	stacks:
	- stackId: production-wasmedge-kwasm
		appType: app
		overrides:
			spinkube-operator:
				version: <string> # version of the spinkube-operator-shim-executor are same for shim-execuator, runtime-class, shim-executor-crd, spinkube-operator
				helmOperatorChartOverridings: <map[string]any> # helm chart overridings, spinkube-operator

			spinkube-operator-shim-executor:
				version: <string> # version of the spinkube-operator-shim-executor are same for shim-execuator, runtime-class, shim-executor-crd, spinkube-operator

			spinkube-operator-runtime-class:
				version: <string> # version of the spinkube-operator-shim-executor are same for shim-execuator, runtime-class, shim-executor-crd, spinkube-operator

			spinkube-operator-crd:
				version: <string> # version of the spinkube-operator-shim-executor are same for shim-execuator, runtime-class, shim-executor-crd, spinkube-operator

			cert-manager:
				version: <string>
				certmanagerChartOverridings: <map[string]any> # helm chart overridings, cert-manager

			kwasm-operator:
				version: <string>
				kwasmOperatorChartOverridings: <map[string]any> # helm chart overridings, kwasm/kwasm-operator

Kwasm

How to use it (Basic Usage)

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: wasm-kwasm
spec:
	stacks:
	- stackId: production-kwasm
		appType: app

Demo app(wasmedge)

---
apiVersion: v1
kind: Pod
metadata:
	name: "myapp"
	namespace: default
	labels:
		app: nice
spec:
	runtimeClassName: wasmedge
	containers:
	- name: myapp
		image: "docker.io/cr7258/wasm-demo-app:v1"
		ports:
		- containerPort: 8080
			name: http
	restartPolicy: Always
---
apiVersion: v1
kind: Service
metadata:
	name: nice
spec:
	selector:
		app: nice
	type: ClusterIP
	ports:
	- name: nice
		protocol: TCP
		port: 8080
		targetPort: 8080

Demo app(wasmtime)

apiVersion: batch/v1
kind: Job
metadata:
  name: nice
  namespace: default
  labels:
    app: nice
spec:
  template:
    metadata:
      name: nice
      labels:
        app: nice
    spec:
      runtimeClassName: wasmtime
      containers:
      - name: nice
        image: "meteatamel/hello-wasm:0.1"
      restartPolicy: OnFailure

#### For wasmedge
# once up and running
kubectl port-forward svc/nice 8080:8080

# then you can curl the service
curl localhost:8080

#### For wasmtime
# just check the logs

Overrides available

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: wasm-wasmedge
spec:
	stacks:
	- stackId: production-kwasm
		appType: app
		overrides:
			kwasm-operator:
				version: <string>
				kwasmOperatorChartOverridings: <map[string]any> # helm chart overridings, kwasm/kwasm-operator

Example usage

Lets deploy argocd@v2.9.X, kube-prometheus-stack@v55.X.Y

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: monitoring-plus-gitops
spec:
	components:
		- appName: standard-argocd
			appType: app
			version: v2.9.12

		- appName: standard-kubeprometheus
			appType: app
			version: "55.0.0"

You can see once its deployed it fetch and deploys them

Lets try to upgrade them to their latest versions

kubeclt edit stack monitoring-plus-gitops

apiVersion: application.ksctl.com/v1alpha1
kind: Stack
metadata:
	name: monitoring-plus-gitops
spec:
	components:
		- appName: standard-argocd
			appType: app
			version: latest

		- appName: standard-kubeprometheus
			appType: app
			version: latest

once edited it will uninstall the previous install and reinstalls the latest deployments

Feedback

Was this page helpful?

Glad to hear it! Please tell us how we can improve.

Sorry to hear that. Please tell us how we can improve.

Last modified December 2, 2024: moved the develop branch (ce07c8f)