Operators are among the most important components of OKD. Operators are the preferred method of packaging, deploying, and managing services on the control plane. They can also provide advantages to applications that users run.
Operators integrate with Kubernetes APIs and CLI tools such as
oc commands. They provide the means of monitoring applications, performing health checks, managing over-the-air (OTA) updates, and ensuring that applications remain in your specified state.
While both follow similar Operator concepts and goals, Operators in OKD are managed by two different systems, depending on their purpose:
Cluster Operators, which are managed by the Cluster Version Operator (CVO), are installed by default to perform cluster functions.
Optional add-on Operators, which are managed by Operator Lifecycle Manager (OLM), can be made accessible for users to run in their applications.
With Operators, you can create applications to monitor the running services in the cluster. Operators are designed specifically for your applications. Operators implement and automate the common Day 1 operations such as installation and configuration as well as Day 2 operations such as autoscaling up and down and creating backups. All these activities are in a piece of software running inside your cluster.
As a developer, you can perform the following Operator tasks:
Create Go-based Operators, Ansible-based Operators, Java-based Operators, and Helm-based Operators.
Create an application from an installed Operator through the web console.
As a cluster administrator, you can perform the following Operator tasks:
To know all about the cluster Operators that Red Hat provides, see Cluster Operators reference.
To understand more about Operators, see What are Operators?