OpenShift.tv: Ask an OpenShift Admin - What’s new in OpenShift 4.7

Good luck and good fortune aligned this week so that the live stream happened on the same day that OpenShift 4.7 was released as generally available. We spent the hour today focused on the new features, capabilities, and functions in 4.7 that are relevant to administrators. See the supporting links section below for the full list of topics and where to find them in the documentation, and don’t hesitate to reach out if you have questions!

If you’re interested in more streaming content, please subscribe to the OpenShift.tv streaming calendar to see the upcoming episode topics and to receive any schedule changes. If you have questions or topic suggestions for the OpenShift Administrator’s Office Hour, please contact us via Discord, Twitter, or come join us live, Wednesdays at 11am EST / 1600 UTC, on YouTube and Twitch.

Episode 18 recorded stream:

Supporting links for today’s topic:

• OpenShift 4.7 release notes, for the full list of new features and changes. Importantly, please don’t forget to check the known issues before upgrading your clusters!
• This OpenShift release is based on Kubernetes 1.20, if you’re interested in more information about what’s in k8s 1.20, see this blog post from Red Hat’s Guarav Singh.
• The OpenShift docs team has been hard at work. They don’t just document the how and why of features, but also spend a lot of time focusing on usability of the documentation. 
• OpenShift 4.6 introduced a section for post-installation configuration.
• OpenShift 4.7 adds sections for role-based organization of the documentation, so you can quickly find the most important documents if you’re an architect, administrator, SRE, or developer. Additionally, there is now documentation on how to validate an install, along with many other new sections.
• Some configuration actions result in the nodes being rebooted. Sometimes this is unavoidable, but OpenShift 4.7 is taking steps to reduce the times that has to happen. You can see the list of changes which no longer result in node reboots here.
• 4.7 introduces IPSec encryption for Pod communications when using the OVN-Kubernetes SDN. More information, including specific traffic flows which are encrypted, can be found here, and you can see how to enable the functionality (at install time only) here.
• The NMState Operator, newly in tech preview with 4.7, brings the ability to configure node networking using a k8s-native paradigm. This is particularly useful if your nodes have additional NICs that need to be configured, for example to connect to an iSCSI storage network, for specialized network configurations, or simply to enable Pod access to additional networks.
• The horizontal Pod autoscaler (HPA) has worked with CPU utilization triggers since it was first introduced to OpenShift. With the release of 4.7, it now works based on memory utilization too! If your application teams are creating Pods with huge memory requests to compensate for the lack of HPA functionality, they can now rely on OpenShift to scale as needed!
• As administrators we often have goals in mind for how we want our nodes to be utilized. Maybe we want to spread the workload across all available nodes so there’s no risk of contention. Maybe we want to pack as much workload on to as few nodes as possible so that the node autoscaler can reduce the cluster size (and save some money in hosting costs!). OpenShift 4.7 has made two features available to make this much, much easier: the Pod descheduler, which is generally available, uses descheduler profiles to combine multiple strategies for maximum effect. And, scheduler profiles provide guidance to the Kubernetes scheduler on how we want Pods to be spread (or not) across the cluster.
• OpenShift GitOps provides declarative configuration for cloud-native applications, including the code, components, and infrastructure deployed to OpenShift. With 4.7, the GitOps Operator provides a way to quickly get started with Argo CD. If you’re interested in learning more, the GitOps Guide to the Galaxy provides a bi-weekly way to interact with us to learn more!

Other links and materials referenced during the stream:

• We discussed how updates to 4.7 may take some time to appear in the stable release channel(s). Be sure to keep an eye on the update graph page, or simply check the update page in your cluster, to see when it’s available.
• We also discussed DHCP and static IPs for control plane nodes. This topic is one that’s come up both internally and externally fairly frequently, and it turns out that OpenShift 4.7 has added some functionality when deploying full-stack automation with physical servers (a.k.a. bare metal IPI). When the nodes detect that their DHCP lease is configured to be infinite, they will automatically convert to using a static IP. Neat!