This release adds improvements related to the following components and concepts.
See the Releases page in the openshift/okd project repository for information on the latest OKD releases.
Operators are pieces of software that ease the operational complexity of running another piece of software. They act like an extension of the software vendor’s engineering team, watching over a Kubernetes environment (such as OKD) and using its current state to make decisions in real time. Advanced Operators are designed to handle upgrades seamlessly, react to failures automatically, and not take shortcuts, like skipping a software backup process to save time.
This feature is now fully supported in OpenShift v4.
The OLM aids cluster administrators in installing, upgrading, and granting access to Operators running on their cluster:
Includes a catalog of curated Operators, with the ability to load other Operators into the cluster
Handles rolling updates of all Operators to new versions
Supports role-based access control (RBAC) for certain teams to use certain Operators
See Understanding the Operator Lifecycle Manager (OLM) for more information.
Red Hat OpenShift v4 has an installer-provisioned infrastructure, where the installation program controls all areas of the installation process. Installer-provisioned infrastructure also provides an opinionated best practices deployment of OpenShift v4 for AWS instances only. This provides a slimmer default installation, with incremental feature buy-in through OperatorHub.
You can also install with a user-provided infrastructure on AWS, bare metal, or vSphere hosts. If you use the installer-provisioned infrastructure installation, the cluster provisions and manages all of the cluster infrastructure for you.
Upgrading from 3.x to 4 is currently not available. You must perform a new installation of OpenShift v4.
Easy, over-the-air upgrades for asynchronous z-stream releases of OpenShift v4 is available. Cluster administrators can upgrade using the Cluster Settings tab in the web console. See Updating a cluster for more information.
OperatorHub is available to administrators and helps with easy discovery and installation of all optional components and applications. It includes offerings from Red Hat products, Red Hat partners, and the community.
Feature | New installer | OperatorHub |
---|---|---|
Console and authentication |
* [x] |
- |
Prometheus cluster monitoring |
* [x] |
- |
Over-the-air updates |
* [x] |
- |
Machine management |
* [x] |
- |
Optional service brokers |
- |
* [x] |
Optional OKD components |
- |
* [x] |
Red Hat product Operators |
- |
* [x] |
Red Hat partner Operators |
- |
* [x] |
Community Operators |
- |
* [x] |
See Understanding the OperatorHub for more information.
Storage support in OpenShift v4 is the same as OpenShift v3 with the exception of the following available in Technology Preview: EFS (CSI Driver handled via Amazon), Manila provisioner/operator, and Snapshot.
Updated guidance around Cluster maximums for OpenShift v4 is now available.
Use the OKD Limit Calculator to estimate cluster limits for your environment.
The Node Tuning Operator is now part of a standard OKD installation in OpenShift v4.
The Node Tuning Operator helps you manage node-level tuning by orchestrating the tuned daemon. The majority of high-performance applications require some level of kernel tuning. The Node Tuning Operator provides a unified management interface to users of node-level sysctls and more flexibility to add custom tuning, which is currently a Technology Preview feature, specified by user needs. The Operator manages the containerized tuned daemon for OpenShift Container Platform as a Kubernetes DaemonSet. It ensures the custom tuning specification is passed to all containerized tuned daemons running in the cluster in the format that the daemons understand. The daemons run on all nodes in the cluster, one per node.
This feature, currently in Technology Preview, enables you to configure horizontal pod autoscaling (HPA) based on the custom metrics API. As part of this Technology Preview, a Prometheus Adapter component can be deployed to provide any app metrics for the custom metrics API.
Limitations:
The adapter only connects to a single Prometheus instance (or a set of load-balanced replicas, using Kubernetes services).
Manually deploying adapter and configuring it to use Prometheus.
Syntax for the Prometheus Adapter configuration could change in the future.
The APIService
configuration to wire Kubernetes' API aggregation to the
instance of the custom metrics adapter will be overwritten in future releases,
if OKD ships an out-of-the-box custom metrics adapter.
An alerting UI is now natively integrated into the OKD web console. You can now view cluster-level alerts and alerting rules from a single place, as well as configure silences.
Telemeter collects anonymized cluster-related metrics to proactively help customers with their OKD clusters. This helps:
Gather crucial health metrics of OKD installations.
Enable a viable feedback loop of OKD upgrades.
Gather the cluster’s number of nodes per cluster and their size (CPU cores and RAM).
Gather the size of etcd.
Gather details about the health condition and status for any OpenShift framework component installed on an OpenShift cluster.
The cluster network is now configured and managed by an Operator. The Operator upgrades and monitors the cluster network.
Multus is a meta plug-in for Kubernetes Container Network Interface (CNI), which enables a user to create multiple network interfaces per pod.
OpenShift v4 features a redesigned Developer Catalog that brings all of the new Operators and existing broker services together, with new ways to discover, sort, and understand how to best use each type of offering. The Developer Catalog is the entry point for a developer to access all services available to them. It merges all capabilities from Operators, the Service Catalog, brokers, and Source-to-Image (S2I).