Operators are among the most important components of OKD. They 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 kubectl
and the OpenShift CLI (oc
). 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.
Operators are designed specifically for Kubernetes-native applications to implement and automate common Day 1 operations, such as installation and configuration. Operators can also automate Day 2 operations, such as autoscaling up or down and creating backups. All of these activities are directed by a piece of software running on your cluster.
While both follow similar Operator concepts and goals, Operators in OKD are managed by two different systems, depending on their purpose:
Managed by the Cluster Version Operator (CVO) and installed by default to perform cluster functions.
Managed by Operator Lifecycle Manager (OLM) and can be made accessible for users to run in their applications. Also known as OLM-based Operators.
As an Operator author, you can perform the following development tasks for OLM-based Operators:
As a cluster administrator, you can perform the following administrative tasks for OLM-based Operators:
For information about the cluster Operators that Red Hat provides, see Cluster Operators reference.
To understand more about Operators, see What are Operators?