Merge pull request kubernetes-sigs#9559 from g-gaston/in-place-working-group

📖 Add In-place upgrades feature group

Author: k8s-ci-robot

docs/community/20231016-in-place-upgrades.md

@@ -0,0 +1,53 @@
+---
+title: Feature Group for In-place Upgrades support in Cluster API
+authors:
+  - "@g-gaston"
+reviewers:
+    - "@dharmjit"
+    - "@vincepri"
+    - "@sbueringer"
+    - "@fabriziopandini"
+creation-date: 2023-10-16
+last-updated: 2023-10-16
+status: proposed
+see-also:
+  - https://github.com/kubernetes-sigs/cluster-api/issues/9489
+  - https://docs.google.com/document/d/1CqQ1SAqJD264PsDeMj_Z3HhZxe7DViNkpJ9d5q-2Zck
+---
+# In-place upgrades Feature Group
+
+This document briefly outlines the scope, communication media, and stakeholders for a formal Feature Group dedicated to defining a Cluster API-approved solution to upgrade the kubernetes components running in CAPI managed nodes without replacing those machines.
+
+## User Story and Problem Statement
+
+As a CAPI Kubernetes cluster admin I want to upgrade the k8s components (for example, a minor Kubernetes upgrade) of my cluster without replacing the machines.
+
+At present, CAPI has "immutable infrastructure" as one of its axioms: once created, Machines are not updated, they are just replaced (a new one is created and old one is deleted). As a consequence, the only supported upgrade strategy is rolling update. However, for certain use cases (such as Single-Node Clusters with no spare capacity, Multi-Node Clusters with VM/OS customizations for high-performance/low-latency workloads or dependency on local persistent storage), upgrading a cluster via RollingUpdate strategy could either be not feasible or a costly operation (requiring to re-apply customizations on newer nodes and hence more downtime).
+
+## Scope
+
+The scope of this effort will be the following:
+
+1. Define the scope of what In-place upgrades means in the context of Cluster API.
+2. Write a CAPI proposal with the recommended solution.
+
+## Communication
+
+We will meet on [Wednesdays at 08:00 PT (Pacific Time)][zoomMeeting]. [Convert to your timezone](https://dateful.com/time-zone-converter?t=09:00&tz=PT%20%28Pacific%20Time%29). Meeting notes will be documented in this [Google Doc](https://docs.google.com/document/d/1GmRd6MyQ0mWAoJV6rCHhZTSTtKMKHdJzhXm0BLBXOnw).
+
+Regular, summarized updates of group progress will be provided during weekly Cluster API office hours on Wednesdays @ 10:00 PT on [Zoom][zoomMeeting].
+
+Chat with stakeholders on Kubernetes [Slack](http://slack.k8s.io/) in the [cluster-api](https://kubernetes.slack.com/archives/C8TSNPY4T) channel.
+
+## Stakeholders
+
+Primary Stakeholders are listed below:
+
+- Mayur Das (@mayur-tolexo, VMware)
+- Alexander Demicev (@alexander-demicev, SUSE)
+- Scott Dodson (@sdodson, Red Hat)
+- Guillermo Gaston (@g-gaston, AWS)
+- Furkat Gofurov (@furkatgofurov7, SUSE)
+- Dharmjit Singh (@dharmjit, VMware)
+
+[zoomMeeting]: https://zoom.us/j/861487554