alexferl / pk8s

Define Kubernetes manifests in Go

pk8s

!IN DEVELOPMENT!

pk8s (Programmable Kubernetes) is a software development framework designed to facilitate the creation of Kubernetes manifests. It allows developers to define, manage, and reuse Kubernetes manifests programmatically, enhancing efficiency and maintainability.

Concepts

pk8s applications are developed using the Go programming language.

At the core of a pk8s project is the App, which serves as the foundational element. Within an App, users have the flexibility to define multiple Stack, representing various environments, clusters, or team. Each Stack can further encapsulate multiple Chart, which are organized collections of Kubernetes resources such as Deployment, Service, Ingress, ReplicaSet, and more.

Using

CLI

The easiest way to get started is using the CLI.

Quickstart

Install:

go install github.com/alexferl/pk8s/pk8s@latest

Init:

pk8s init infra

Output:

  Your pk8s Go project is ready! 🚀✨

    📤 pk8s export  Export Kubernetes manifests to dist/
    📥 pk8s import  Import custom resource definitions to imports/

  Deploy:
    🛠️ kubectl apply -f dist/

Change directory:

cd infra

Export:

pk8s export

Output:

Generated Kubernetes manifests:
  dev:
    - dist/dev/hello.yaml

And if you check the content of dist/dev/hello.yaml:

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-24cf642e

Note: the apiVersion and kind fields are automatically populated on generation for resources that require them.

You can now edit main.go and add more stacks and charts and repeat the export process to generate new manifests.

Code

If you can't or don't want to use the CLI, you can also directly use the library.

Quickstart

Install:

go get github.com/alexferl/pk8s

Create a main.go file with the following content:

package main

import (
	"github.com/alexferl/pk8s"
	"github.com/alexferl/pk8s/k8s"
)

type ChartParams struct {
	pk8s.ChartParams
}

func NewChart(stack *pk8s.Stack, name string, params *ChartParams) *pk8s.Chart {
	var chartParams pk8s.ChartParams
	if params != nil {
		chartParams = params.ChartParams
	}
	chart := pk8s.NewChart(stack, name, &chartParams)

	deployment := &k8s.DeploymentV1{
		// ...
	}

	chart.Append(deployment)

	return chart
}

func main() {
	app := pk8s.New()
	stack := pk8s.NewStack(app, "dev")

	NewChart(stack, "hello", nil)

	app.Export()
}

Run it:

go run main.go

Output:

Generated Kubernetes manifests:
  dev:
    - dist/dev/hello.yaml

Examples

See the examples directory for more complex examples.

FAQ

1. Who is this for?
   • Software developers, DevOps engineers, and Kubernetes users who prefer defining Kubernetes resources programmatically rather than using YAML.
2. Why not just use cdk8s?
   • cdk8s is a robust tool for managing Kubernetes configurations, but its CLI depends on Node.js since it is fundamentally a JavaScript-based project. While it provides bindings for other languages, such as Go, the generated code may occasionally result in less elegant and idiomatic implementations in those languages.