What are Kubernetes Operators & How do they Work (with Examples))

Managing and scaling containerized applications has become a big challenge for developers and operations teams alike in the vast tech space.

That's where Kubernetes Operators come into action.

This blog explores everything you need to know about Kubernetes Operators. From understanding their role in automating complex tasks to witnessing how they seamlessly integrate with your existing infrastructure

What is a Kubernetes Operator?

The Kubernetes Operator is a custom resource controller, an extension of the Kubernetes API. Its main purpose is to simplify and automate the management of complex applications and workloads within a Kubernetes cluster.

This capability automatically empowers users to handle software updates, configuration changes, and even failure scenarios.

This further reduces manual intervention and streamlines the overall container orchestration process.

Also Read: What is Configuration as Code?

How do Kubernetes Operators Work?

Kubernetes custom resources and controllers are used by operators to automate the management of particular workloads and applications.

When users deploy a Kubernetes Operator, it's similar to assigning an expert to a certain service and application. They monitor the behavior of the program constantly to make sure it conforms to the users' desired state.

If anything goes wrong, the Kubernetes Operator swings into action, making the appropriate modifications, and restoring the clusters.

Operators make use of custom resources, which are Kubernetes API extensions that describe the current state of specific applications.

These unique resources act as a medium through which you explain to the Operator what you intend.

The Operator's controller then decodes these custom resources and responds appropriately, carrying out the required operations to preserve the desired state of an application.

Top 6 Kubernetes Operators to Use for Your Deployments

Let's have a look at top 6 Kubernetes Operators you can use for your next deployments.

RBAC Manager Operator

The RBAC Manager Operator is a powerful tool that empowers organizations to manage their Role-Based Access Control (RBAC) setup efficiently.

With this operator on board, you can effortlessly create, modify, and delete roles, assign user roles, and set permissions for those roles.

It ensures smooth sailing by providing key features like role management, assignment management, and detailed insights into role and assignment details.

It allows you to leave notes and comments, collaborate and track changes in your RBAC setup.

Also Read: Differences between Grafana and Datadog

Grafana Operator

Grafana Operator offers a seamless way to handle Grafana, the monitoring and visualization tool.

It comes packed with automation features such as deployment via Terraform, automated scaling using Prometheus Alertmanager, and data protection through automated backups with Arq Backup.

The Operator seamlessly integrates with Prometheus for real-time monitoring of Grafana instances and Elasticsearch for smooth logging.

Also Read: Prometheus Operator Tutorial

HPA Kubernetes Operator

The HPA Kubernetes Operator framework is an open-source project to monitor and manage Kubernetes nodes in a cluster.

It offers a simple yet powerful solution for efficiently overseeing and maintaining the health of your Kubernetes infrastructure.

The operator can be deployed on various environments, such as cloud providers, bare metal, or virtual machines.

Istio Operator

The Istio Operator brings seamless orchestration, security, monitoring, and management to microservices deployed on Kubernetes.

It streamlines various tasks, making installation, upgrades, and troubleshooting of Istio a breeze. The operator API supports all six built-in installation configuration profiles, including demo, default, and remote.

With the Istio Operator, handling Istio in your Kubernetes environment becomes a straightforward process.

Also Read: Consul vs Istio vs Linkerd

Starboard Operator

The Starboard Operator t seamlessly integrates security tools into your Kubernetes environment. With Starboard, you can effortlessly identify and assess risks associated with different resources within your Kubernetes cluster.

The operator automatically updates the security report resource in response to changes in cluster workloads. That ensures real-time vulnerability scans and configuration audits.

Also Read: Splunk vs ELK Stack

Elastic Cloud on Kubernetes (ECK)

The Elastic Cloud on Kubernetes (ECK), also known as Elastic Kubernetes Operator, is the official open-source operator tailored specifically for the Elastic Stack (ELK).

It offers seamless deployment and management of ECK, encompassing essential components like Elasticsearch, Kibana, and Logstash.

ECK empowers users with valuable features, including cluster monitoring, automated upgrades, scheduled backups, and dynamic scalability of local storage.

How Can Operators Manage Kubernetes Applications?

Operators are crucial in managing Kubernetes applications by providing an automated and intelligent approach. They extend the Kubernetes API, allowing users to define custom resources that sum up the operational logic for specific applications.

When deployed, Operators continuously monitor the desired state of these custom resources and take action to ensure the applications conform to the defined state.

This includes provisioning, scaling, upgrading, and even handling failure scenarios.

By automating these complex and repetitive tasks, Operators streamline application management, reduce manual intervention, and enhance the overall efficiency of the Kubernetes ecosystem.

Their ability to understand the nuances of each application's requirements empowers developers and operators to focus on innovation and productivity.

Also Read: Opensearch vs Elasticsearch

What is the Operator SDK in Kubernetes?

The Operator SDK in Kubernetes is a toolkit created to make it easier to create unique Kubernetes operators. It offers programmers the fundamental frameworks and tools they need to create Operators quickly and efficiently.

Developers can concentrate on the distinctive logic of their apps with the operator SDK While leaving the repetitive Operator boilerplate code to SDK.

As a result, it's simpler to construct sophisticated Operators that can handle unique resources and automate intricate activities within Kubernetes.

Developers who want to add potent, automation-driven operators to their Kubernetes applications can benefit greatly from the Operator SDK.

Also Read: Differences between GitOps and DevOps

Kubernetes Operators vs. Helm Charts

Kubernetes Operators and Helm charts are both strong tools in the Kubernetes ecosystem, but they have different uses.

The Kubernetes API extended by Operators allows for the automation of complex application management tasks. They offer intelligent automation and are made to manage the lifespan of particular applications.

On the other hand, Kubernetes applications are defined and deployed using Helm charts. They concentrate on resource templating and configuring, making deploying applications consistently across environments easier.

While Helm charts are excellent for streamlining the deployment of applications, Kubernetes Operators go one step further by automating deployment and day-to-day management tasks, enabling more sophisticated and fine-grained control.

Both are useful tools, and the optimal way to use them will depend upon the particular requirements and complexity of your Kubernetes system.

Also Read: What is Internal Developer Platform?

Kubernetes Operators vs Controllers

Kubernetes Operators and Controllers are both crucial parts of the system, but they have different functions.

Controllers are built-in components of the Kubernetes control plane responsible for maintaining the desired state of resources and handling events within the cluster.

They include ReplicaSet, Deployment, StatefulSet, and more.

The Kubernetes Operators, on the other hand, are custom resource controllers created to extend the Kubernetes API and automate the management of specific applications or custom resources.

Operators are more specialized and cater to the unique requirements of applications. That provides intelligent automation for tasks beyond the scope of built-in controllers.

While Controllers offer fundamental functionality for resource management, Kubernetes Operators offer a higher level of abstraction and customization for complex application orchestration.

This makes them a valuable addition to the Kubernetes ecosystem.

Also Read: Kubernetes Best Practices

Kubernetes Operators vs. CRDs

Kubernetes Operators and Custom Resource Definitions (CRDs) are two separate but related concepts in Kubernetes.

CRDs are an addition to the Kubernetes API that let users create unique resources tailored to the demands of their particular applications.

Users can store and manage application-specific data using these resources, which represent new object types in Kubernetes.

On the other hand, Kubernetes Operators are custom controllers that leverage CRDs to automate the management of these custom resources.

Operators use the Kubernetes API and watch for changes to custom resources, enabling them to take intelligent actions and ensure the desired state of applications.

Frequently Asked Questions

What is the difference between an operator and a controller in Kubernetes?

Controllers maintain the desired state for built-in resources, while operators automate management for custom resources or complex applications.

What are the different types of controllers in Kubernetes?

The controllers in Kubernetes include ReplicaSet, Deployment, StatefulSet, DaemonSet, Job, CronJob, and more.

Further Reading