The Kubernetes Operator Pattern

Daniel Chernenkov
2 min readJan 13, 2023

Kubernetes Operator is a powerful tool for managing and scaling applications on the Kubernetes platform. It allows developers to easily create, configure, and manage applications within a Kubernetes cluster.

One of the key benefits of using Kubernetes Operator is its ability to automate tasks that would otherwise have to be done manually. For example, an operator can automatically scale an application based on resource usage, or automatically update the application to the latest version. This can save a lot of time and effort for developers, and also ensures that applications are running smoothly and efficiently.

Another benefit of Kubernetes Operator is its ability to manage the entire application lifecycle. This includes creating and configuring the application, scaling it up or down as needed, and performing updates and upgrades. This makes it easier for developers to focus on writing code and creating new features, rather than managing the infrastructure.

Kubernetes Operator is also highly customizable, allowing developers to tailor it to their specific needs. This includes creating custom resources and controllers, as well as integrating with other tools and services.

Overall, Kubernetes Operator is an incredibly powerful tool for managing and scaling applications on the Kubernetes platform. It can save time and effort for developers, and also ensures that applications are running smoothly and efficiently. It’s an essential tool for anyone working with Kubernetes and looking to take their applications to the next level.

package main

import (
"fmt"
"time"

"github.com/operator-framework/operator-sdk/pkg/sdk"
sdkVersion "github.com/operator-framework/operator-sdk/version"
"github.com/sirupsen/logrus"
_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
)

func main() {
sdk.ExposeMetricsPort()

resource := "example.com/v1alpha1"
kind := "Example"
namespace, err := sdk.GetWatchNamespace()
if err != nil {
logrus.Fatalf("Failed to get watch namespace: %v", err)
}
resyncPeriod := time.Duration(5) * time.Second
logrus.Infof("Watching %s, %s, %s, %d", resource, kind, namespace, resyncPeriod)
sdk.Watch(resource, kind, namespace, resyncPeriod)
sdk.Handle(sdk.NewHandler())
sdk.Run(nil)
}

This code sets up a basic operator that watches for changes to a specific resource, in this case “example.com/v1alpha1”, and a specific kind, in this case “Example”. It also sets up a resync period of 5 seconds, so the operator will check for changes every 5 seconds.

It’s important to note that this is just a basic example and depending on your use case, you might need to add more functionality to your operator. Additionally, this example is written in Go, but you can also write Kubernetes Operators using other languages such as Python.

I recommend you to check the Kubernetes Operator Framework documentation for more detailed and specific examples: https://kubernetes.io/docs/concepts/extend-kubernetes/operator/

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Daniel Chernenkov

I specialize in leading complex software projects and system designs, coordinating with diverse, international teams.