6 Cool Kubernetes Operators and How to Use Them

What Are Kubernetes Operators?

Kubernetes operators are software extensions that enable the automation of operational tasks. This concept was introduced by CoreOS in 2016 and has since gained traction in the DevOps community. Operators allow developers to package, deploy, and manage a Kubernetes application.

They are built to handle the "human knowledge" part of managing services and automating tasks like deployment, scaling, backups, and recovery.

An operator in Kubernetes leverages custom resources to manage applications and their components. Kubernetes operators are created using the Operator Framework—an open-source toolkit that lets you manage Kubernetes native applications in a more effective way. It includes the Operator SDK, Operator Lifecycle Manager, and Operator Metering. It's like having an experienced on-site engineer making real-time decisions on your applications.

The main component of a Kubernetes operator is the custom controller, which contains the domain-specific knowledge required to run an application. The controller watches the state of your application, and when it deviates from the desired state, the operator takes corrective action. Read this blog post for more background on Kubernetes operators.

Benefits of Using Kubernetes Operators

Kubernetes operators have numerous advantages that make them integral to scalable and efficient cloud-native development.

Operators simplify complex software management tasks. You can automate updates, backups, failovers, and scaling, which are otherwise labor-intensive tasks. With operators, you can easily manage stateful applications, which are notoriously difficult to automate and manage. This leads to more efficiency and time-saving.

Operators also handle operational complexity with ease. They encapsulate the human operator's knowledge into software, allowing for automatic adjustment and recovery from failures. They also ensure that applications are running in the desired state, making them self-healing. This reduces the need for manual intervention and decreases the chance of human error.

6 Cool Kubernetes Operators and How to Use Them

Operator Framework

The Operator Framework is an open-source toolkit that allows developers and operators to build, test, and deploy operators. It provides high-level APIs and abstractions to run and manage applications on Kubernetes.

The Operator Framework includes several components, such as the Operator SDK, Operator Lifecycle Manager (OLM), and Operator Metering. The SDK facilitates the development of operators based on Go, Ansible, or Helm. The OLM oversees the installation, update, and management of the lifecycle of all of the operators running across a Kubernetes cluster. Operator Metering is for usage reporting.

How to use it:

To use the Operator Framework, start by installing the Operator SDK which is a component of the framework. This can be done using package managers like yum for Red Hat-based systems or brew for macOS. Once installed, you can create a new operator project using the SDK for your choice of framework (Go, Ansible, or Helm).

After setting up the project, define custom resource definitions (CRDs) for your application. The next step involves writing the reconciliation logic for your operator, which defines how your application should be deployed and managed. Finally, use the Operator Lifecycle Manager (OLM) to deploy and manage your operator in a Kubernetes cluster, ensuring it handles the lifecycle of your application effectively.

Prometheus Operator

The Prometheus operator is a Kubernetes operator that provides easy monitoring definitions for Kubernetes services and deployment. It creates, configures, and manages Prometheus clusters in Kubernetes. Prometheus is an open-source systems monitoring and alerting toolkit that can handle multi-dimensional data collection.

The Prometheus operator also makes it easier to configure and manage instances of Prometheus, Alertmanager, and related monitoring components. It brings the benefits of automation and declarative configuration to monitoring your Kubernetes applications.

How to use it:

To use the Prometheus operator, first, ensure that you have a Kubernetes cluster running. Begin by deploying the Prometheus operator in your cluster, which can typically be done using Helm charts or directly applying YAML files in Kubernetes.

After the operator is deployed, create a ServiceMonitor custom resource for each application you want to monitor. This custom resource specifies how the Prometheus operator should discover and scrape metrics from your application. Finally, configure Prometheus Alertmanager to handle alerts generated by Prometheus.

The etcd Operator

etcd is a distributed reliable key-value store that is simple, secure, and fast. The etcd operator automates tasks related to operating an etcd cluster on Kubernetes. It handles tasks like creating and destroying clusters, resizing clusters, and performing automatic backups.

The etcd operator is particularly useful for managing etcd clusters for large-scale Kubernetes deployments. It simplifies the process of scaling up and down your etcd clusters, making it easier to handle high-load scenarios.

How to use it:

To use the etcd operator, you must first install it in your Kubernetes cluster, which can be achieved through Helm charts or by applying YAML files directly. Once installed, create an EtcdCluster custom resource, specifying the desired number of nodes and configuration for your etcd cluster.

The operator will then automatically create, configure, and manage the etcd nodes. You can also use the operator to perform tasks like backups, restores, and version upgrades by modifying the EtcdCluster resource or using additional custom resources provided by the operator.

Vault Operator

The Vault operator automates tasks related to operating Vault clusters on Kubernetes. Vault is a tool for securely accessing secrets, such as API keys, passwords, or certificates.

This operator provides an easy way to deploy and manage Vault clusters in a Kubernetes environment. The Vault operator is essential for securing your Kubernetes applications. It ensures that your secrets are securely stored and accessed, reducing the risk of security breaches.

How to use it:

Using the Vault operator involves installing the operator in your Kubernetes cluster, similar to the other operators. After installation, create a Vault custom resource, which defines the configuration and deployment details of your Vault cluster.

The operator will use this resource to deploy and manage a Vault instance in your cluster. You can then interact with Vault using its API or CLI, creating and managing secrets as required by your applications.

Rook Operator

The Rook operator is a storage operator for Kubernetes. It automates tasks related to operating storage systems on Kubernetes. Rook turns distributed storage systems into self-managing, self-scaling, and self-healing storage services.

The Rook operator is particularly useful for managing large-scale storage systems. It ensures that your storage services are always available, resilient, and performing optimally.

How to use it:

To use the Rook operator, start by installing it in your Kubernetes cluster, which can be done using Helm or by applying YAML manifests.

Once the Rook operator is installed, define a CephCluster resource to deploy a Ceph storage cluster, specifying the desired configuration and storage resources.

The operator will manage the Ceph cluster, automating tasks like deployment, scaling, and health monitoring. You can then use the Ceph storage provided by Rook for your Kubernetes applications.

Jaeger Operator

Jaeger is an open-source, end-to-end distributed tracing system. The Jaeger operator automates tasks related to operating Jaeger on Kubernetes, such as deploying, configuring, and managing instances of Jaeger.

The Jaeger operator is useful for troubleshooting and monitoring your Kubernetes applications. It provides insights into how your applications are performing, helping you identify and resolve issues faster.

How to use it:

To use the Jaeger operator, install it in your Kubernetes cluster via Helm charts or YAML files. After installation, create a Jaeger custom resource, defining the configuration for your Jaeger instance.

The operator will deploy and manage Jaeger components based on this configuration. You can then integrate Jaeger with your applications for distributed tracing, allowing you to monitor and troubleshoot application performance issues efficiently.

Conclusion

Kubernetes operators are a powerful tool for simplifying and automating the management of your Kubernetes applications. Whether you're dealing with monitoring, storage, secrets management, or distributed tracing, there's likely a Kubernetes operator that can make your life easier.

Start exploring these amazing tools today, and take your Kubernetes game to the next level.