Chapter 1. Operators overview
Operators are among the most important components of OpenShift Container Platform. 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 OpenShift Container Platform are managed by two different systems, depending on their purpose:
- Cluster Operators
- Managed by the Cluster Version Operator (CVO) and installed by default to perform cluster functions.
- Optional add-on Operators
- Managed by Operator Lifecycle Manager (OLM) and can be made accessible for users to run in their applications. Also known as OLM-based Operators.
1.1. For developers
As an Operator author, you can perform the following development tasks for OLM-based Operators:
- Install Operator SDK CLI.
- Create Go-based Operators, Ansible-based Operators, Java-based Operators, and Helm-based Operators.
- Use Operator SDK to build, test, and deploy an Operator.
- Install and subscribe an Operator to your namespace.
- Create an application from an installed Operator through the web console.
Additional resources
1.2. For administrators
As a cluster administrator, you can perform the following administrative tasks for OLM-based Operators:
- Manage custom catalogs.
- Allow non-cluster administrators to install Operators.
- Install an Operator from OperatorHub.
- View Operator status.
- Manage Operator conditions.
- Upgrade installed Operators.
- Delete installed Operators.
- Configure proxy support.
- Use Operator Lifecycle Manager on restricted networks.
For information about the cluster Operators that Red Hat provides, see Cluster Operators reference.
1.3. Next steps
To understand more about Operators, see What are Operators?