Cozystack v0.31.0 is a significant release that brings new features, key fixes, and updates to underlying components.
This version enhances GPU support, improves many components of Cozystack, and introduces a more robust release process to improve stability.
Below, we'll go over the highlights in each area for current users, developers, and our community.

## Major Features and Improvements

### GPU support for tenant Kubernetes clusters

Cozystack now integrates NVIDIA GPU Operator support for tenant Kubernetes clusters.
This enables platform users to run GPU-powered AI/ML applications in their own clusters.
To enable GPU Operator, set `addons.gpuOperator.enabled: true` in the cluster configuration.
(@kvaps in https://github.com/cozystack/cozystack/pull/834)

Check out Andrei Kvapil's CNCF webinar [showcasing the GPU support by running Stable Diffusion in Cozystack](https://www.youtube.com/watch?v=S__h_QaoYEk).

<!--
* [kubernetes] Introduce GPU support for tenant Kubernetes clusters. (@kvaps in https://github.com/cozystack/cozystack/pull/834)
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### Cilium Improvements

Cozystack’s Cilium integration received two significant enhancements.
First, Gateway API support in Cilium is now enabled, allowing advanced L4/L7 routing features via Kubernetes Gateway API.
We thank Zdenek Janda @zdenekjanda for contributing this feature in https://github.com/cozystack/cozystack/pull/924.

Second, Cozystack now permits custom user-provided parameters in the tenant cluster’s Cilium configuration.
(@lllamnyp in https://github.com/cozystack/cozystack/pull/917)

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* [cilium] Enable Cilium Gateway API. (@zdenekjanda in https://github.com/cozystack/cozystack/pull/924)
* [cilium] Enable user-added parameters in a tenant cluster Cilium. (@lllamnyp in https://github.com/cozystack/cozystack/pull/917)
-->

### Cross-Architecture Builds (ARM Support Beta)

Cozystack's build system was refactored to support multi-architecture binaries and container images.
This paves the road to running Cozystack on ARM64 servers.
Changes include Makefile improvements (https://github.com/cozystack/cozystack/pull/907)
and multi-arch Docker image builds (https://github.com/cozystack/cozystack/pull/932 and https://github.com/cozystack/cozystack/pull/970).

We thank Nikita Bykov @nbykov0 for his ongoing work on ARM support!

<!--
* Introduce support for cross-architecture builds and Cozystack on ARM:
    * [build] Refactor Makefiles introducing build variables. (@nbykov0 in https://github.com/cozystack/cozystack/pull/907)
    * [build] Add support for multi-architecture and cross-platform image builds. (@nbykov0 in https://github.com/cozystack/cozystack/pull/932 and https://github.com/cozystack/cozystack/pull/970)
-->

### VerticalPodAutoscaler (VPA) Expansion

The VerticalPodAutoscaler is now enabled for more Cozystack components to automate resource tuning.
Specifically, VPA was added for tenant Kubernetes control planes (@klinch0 in https://github.com/cozystack/cozystack/pull/806),
the Cozystack Dashboard (https://github.com/cozystack/cozystack/pull/828),
and the Cozystack etcd-operator (https://github.com/cozystack/cozystack/pull/850).
All Cozystack components that have VPA enabled can automatically adjust their CPU and memory requests based on usage, improving platform and application stability.

<!--
* Add VerticalPodAutoscaler to a few more components:
    * [kubernetes] Kubernetes clusters in user tenants. (@klinch0 in https://github.com/cozystack/cozystack/pull/806)
    * [platform] Cozystack dashboard. (@klinch0 in https://github.com/cozystack/cozystack/pull/828)
    * [platform] Cozystack etcd-operator (@klinch0 in https://github.com/cozystack/cozystack/pull/850)
-->

### Tenant HelmRelease Reconcile Controller

A new controller was introduced to monitor and synchronize HelmRelease resources across tenants.
This controller propagates configuration changes to tenant workloads and ensures that any HelmRelease defined in a tenant
stays in sync with platform updates.
It improves the reliability of deploying managed applications in Cozystack.
(@klinch0 in https://github.com/cozystack/cozystack/pull/870)

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* [platform] Introduce a new controller to synchronize tenant HelmReleases and propagate configuration changes. (@klinch0 in https://github.com/cozystack/cozystack/pull/870)
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### Virtual Machine Improvements

**Configurable KubeVirt CPU Overcommit**: The CPU allocation ratio in KubeVirt (how virtual CPUs are overcommitted relative to physical) is now configurable
via the `cpu-allocation-ratio` value in the Cozystack configmap.
This means Cozystack administrators can now tune CPU overcommitment for VMs to balance performance vs. density.
(@lllamnyp in https://github.com/cozystack/cozystack/pull/905)

**KubeVirt VM Export**: Cozystack now allows exporting KubeVirt virtual machines.
This feature, enabled via KubeVirt's `VirtualMachineExport` capability, lets users snapshot or back up VM images.
(@kvaps in https://github.com/cozystack/cozystack/pull/808)

**Support for various storage classes in Virtual Machines**: The `virtual-machine` application (since version 0.9.2) lets you pick any StorageClass for a VM's 
system disk instead of relying on a hard-coded PVC.
Refer to values `systemDisk.storage` and `systemDisk.storageClass` in the [application's configs](https://cozystack.io/docs/reference/applications/virtual-machine/#common-parameters).
(@kvaps in https://github.com/cozystack/cozystack/pull/974)

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* [kubevirt] Enable exporting VMs. (@kvaps in https://github.com/cozystack/cozystack/pull/808)
* [kubevirt] Make KubeVirt's CPU allocation ratio configurable. (@lllamnyp in https://github.com/cozystack/cozystack/pull/905)
* [virtual-machine] Add support for various storages. (@kvaps in https://github.com/cozystack/cozystack/pull/974)
-->

### Other Features and Improvements

* [platform] Introduce options `expose-services`, `expose-ingress`, and `expose-external-ips` to the ingress service. (@kvaps in https://github.com/cozystack/cozystack/pull/929)
* [cozystack-controller] Record the IP address pool and storage class in Workload objects. (@lllamnyp in https://github.com/cozystack/cozystack/pull/831)
* [apps] Remove user-facing config of limits and requests. (@lllamnyp in https://github.com/cozystack/cozystack/pull/935)

## New Release Lifecycle

Cozystack release lifecycle is changing to provide a more stable and predictable lifecycle to customers running Cozystack in mission-critical environments.

* **Gradual Release with Alpha, Beta, and Release Candidates**: Cozystack will now publish pre-release versions (alpha, beta, release candidates) before a stable release.
  Starting with v0.31.0, the team made three release candidates before releasing version v0.31.0.
  This allows more testing and feedback before marking a release as stable.

* **Prolonged Release Support with Patch Versions**: After the initial `vX.Y.0` release, a long-lived branch `release-X.Y` will be created to backport fixes.
  For example, with 0.31.0’s release, a `release-0.31` branch will track patch fixes (`0.31.x`).
  This strategy lets Cozystack users receive timely patch releases and updates with minimal risks.

To implement these new changes, we have rebuilt our CI/CD workflows and introduced automation, enabling automatic backports.
You can read more about how it's implemented in the Development section below.

For more information, read the [Cozystack Release Workflow](https://github.com/cozystack/cozystack/blob/main/docs/release.md) documentation.

## Fixes

* [virtual-machine] Add GPU names to the virtual machine specifications. (@kvaps in https://github.com/cozystack/cozystack/pull/862)
* [virtual-machine] Count Workload resources for pods by requests, not limits. Other improvements to VM resource tracking. (@lllamnyp in https://github.com/cozystack/cozystack/pull/904)
* [virtual-machine] Set PortList method by default. (@kvaps in https://github.com/cozystack/cozystack/pull/996)
* [virtual-machine] Specify ports even for wholeIP mode. (@kvaps in https://github.com/cozystack/cozystack/pull/1000)
* [platform] Fix installing HelmReleases on initial setup. (@kvaps in https://github.com/cozystack/cozystack/pull/833)
* [platform] Migration scripts update Kubernetes ConfigMap with the current stack version for improved version tracking. (@klinch0 in https://github.com/cozystack/cozystack/pull/840)
* [platform] Reduce requested CPU and RAM for the `kamaji` provider. (@klinch0 in https://github.com/cozystack/cozystack/pull/825)
* [platform] Improve the reconciliation loop for the Cozystack system HelmReleases logic. (@klinch0 in https://github.com/cozystack/cozystack/pull/809 and https://github.com/cozystack/cozystack/pull/810, @kvaps in https://github.com/cozystack/cozystack/pull/811)
* [platform] Remove extra dependencies for the Piraeus operator. (@klinch0 in https://github.com/cozystack/cozystack/pull/856)
* [platform] Refactor dashboard values. (@kvaps in https://github.com/cozystack/cozystack/pull/928, patched by @llamnyp in https://github.com/cozystack/cozystack/pull/952)
* [platform] Make FluxCD artifact disabled by default. (@klinch0 in https://github.com/cozystack/cozystack/pull/964)
* [kubernetes] Update garbage collection of HelmReleases in tenant Kubernetes clusters. (@kvaps in https://github.com/cozystack/cozystack/pull/835)
* [kubernetes] Fix merging `valuesOverride` for tenant clusters. (@kvaps in https://github.com/cozystack/cozystack/pull/879)
* [kubernetes] Fix `ubuntu-container-disk` tag. (@kvaps in https://github.com/cozystack/cozystack/pull/887)
* [kubernetes] Refactor Helm manifests for tenant Kubernetes clusters. (@kvaps in https://github.com/cozystack/cozystack/pull/866)
* [kubernetes] Fix Ingress-NGINX depends on Cert-Manager. (@kvaps in https://github.com/cozystack/cozystack/pull/976)
* [kubernetes, apps] Enable `topologySpreadConstraints` for tenant Kubernetes clusters and fix it for managed PostgreSQL. (@klinch0 in https://github.com/cozystack/cozystack/pull/995)
* [tenant] Fix an issue with accessing external IPs of a cluster from the cluster itself. (@kvaps in https://github.com/cozystack/cozystack/pull/854)
* [cluster-api] Remove the no longer necessary workaround for Kamaji. (@kvaps in https://github.com/cozystack/cozystack/pull/867, patched in https://github.com/cozystack/cozystack/pull/956) 
* [monitoring] Remove legacy label "POD" from the exclude filter in metrics. (@xy2 in https://github.com/cozystack/cozystack/pull/826)
* [monitoring] Refactor management etcd monitoring config. Introduce a migration script for updating monitoring resources (`kube-rbac-proxy` daemonset). (@lllamnyp in https://github.com/cozystack/cozystack/pull/799 and https://github.com/cozystack/cozystack/pull/830)
* [monitoring] Fix VerticalPodAutoscaler resource allocation for VMagent. (@klinch0 in https://github.com/cozystack/cozystack/pull/820)
* [postgres] Remove duplicated `template` entry from backup manifest. (@etoshutka in https://github.com/cozystack/cozystack/pull/872)
* [kube-ovn] Fix versions mapping in Makefile. (@kvaps in https://github.com/cozystack/cozystack/pull/883)
* [dx] Automatically detect version for migrations in the installer.sh. (@kvaps in https://github.com/cozystack/cozystack/pull/837)
* [dx] remove version_map and building for library charts. (@kvaps in https://github.com/cozystack/cozystack/pull/998)
* [docs] Review the tenant Kubernetes cluster docs. (@NickVolynkin in https://github.com/cozystack/cozystack/pull/969)
* [docs] Explain that tenants cannot have dashes in their names. (@NickVolynkin in https://github.com/cozystack/cozystack/pull/980)

## Dependencies

* MetalLB images are now built in-tree based on version 0.14.9 with additional critical patches. (@lllamnyp in https://github.com/cozystack/cozystack/pull/945)
* Update Kubernetes to v1.32.4. (@kvaps in https://github.com/cozystack/cozystack/pull/949)
* Update Talos Linux to v1.10.1. (@kvaps in https://github.com/cozystack/cozystack/pull/931)
* Update Cilium to v1.17.3. (@kvaps in https://github.com/cozystack/cozystack/pull/848)
* Update LINSTOR to v1.31.0. (@kvaps in https://github.com/cozystack/cozystack/pull/846)
* Update Kube-OVN to v1.13.11. (@kvaps in https://github.com/cozystack/cozystack/pull/847, @lllamnyp in https://github.com/cozystack/cozystack/pull/922)
* Update tenant Kubernetes to v1.32. (@kvaps in https://github.com/cozystack/cozystack/pull/871)
* Update flux-operator to 0.20.0. (@kingdonb in https://github.com/cozystack/cozystack/pull/880 and https://github.com/cozystack/cozystack/pull/934)
* Update multiple Cluster API components. (@kvaps in https://github.com/cozystack/cozystack/pull/867 and https://github.com/cozystack/cozystack/pull/947)
* Update KamajiControlPlane to edge-25.4.1. (@kvaps in https://github.com/cozystack/cozystack/pull/953, fixed by @nbykov0 in https://github.com/cozystack/cozystack/pull/983)
* Update cert-manager to v1.17.2. (@kvaps in https://github.com/cozystack/cozystack/pull/975)

## Documentation

* [Installing Talos in Air-Gapped Environment](https://cozystack.io/docs/operations/talos/configuration/air-gapped/):
  new guide for configuring and bootstrapping Talos Linux clusters in air-gapped environments.
  (@klinch0 in https://github.com/cozystack/website/pull/203)

* [Cozystack Bundles](https://cozystack.io/docs/guides/bundles/): new page in the learning section explaining how Cozystack bundles work and how to choose a bundle.
  (@NickVolynkin in https://github.com/cozystack/website/pull/188, https://github.com/cozystack/website/pull/189, and others;
  updated by @kvaps in https://github.com/cozystack/website/pull/192 and https://github.com/cozystack/website/pull/193)

* [Managed Application Reference](https://cozystack.io/docs/reference/applications/): A set of new pages in the docs, mirroring application docs from the Cozystack dashboard.
  (@NickVolynkin in https://github.com/cozystack/website/pull/198, https://github.com/cozystack/website/pull/202, and https://github.com/cozystack/website/pull/204)

* **LINSTOR Networking**: Guides on [configuring dedicated network for LINSTOR](https://cozystack.io/docs/operations/storage/dedicated-network/)
and [configuring network for distributed storage in multi-datacenter setup](https://cozystack.io/docs/operations/stretched/linstor-dedicated-network/).
(@xy2, edited by @NickVolynkin in https://github.com/cozystack/website/pull/171, https://github.com/cozystack/website/pull/182, and https://github.com/cozystack/website/pull/184)

### Fixes

* Correct error in the doc for the command to edit the configmap. (@lb0o in https://github.com/cozystack/website/pull/207)
* Fix group name in OIDC docs (@kingdonb in https://github.com/cozystack/website/pull/179)
* A bit more explanation of Docker buildx builders. (@nbykov0 in https://github.com/cozystack/website/pull/187)

## Development, Testing, and CI/CD

### Testing

Improvements:

* Introduce `cozytest` — a new [BATS-based](https://github.com/bats-core/bats-core) testing framework. (@kvaps in https://github.com/cozystack/cozystack/pull/982)

Fixes:

* Fix `device_ownership_from_security_context` CRI. (@dtrdnk in https://github.com/cozystack/cozystack/pull/896)
* Increase timeout durations for `capi` and `keycloak` to improve reliability during e2e-tests. (@kvaps in https://github.com/cozystack/cozystack/pull/858)
* Return `genisoimage` to the e2e-test Dockerfile (@gwynbleidd2106 in https://github.com/cozystack/cozystack/pull/962)

### CI/CD Changes
                          
Improvements:

* Use release branches `release-X.Y` for gathering and releasing fixes after initial `vX.Y.0` release. (@kvaps in https://github.com/cozystack/cozystack/pull/816)
* Automatically create release branches after initial `vX.Y.0` release is published. (@kvaps in https://github.com/cozystack/cozystack/pull/886)
* Introduce Release Candidate versions. Automate patch backporting by applying patches from pull requests labeled `[backport]` to the current release branch. (@kvaps in https://github.com/cozystack/cozystack/pull/841 and https://github.com/cozystack/cozystack/pull/901, @nickvolynkin in https://github.com/cozystack/cozystack/pull/890)
* Support alpha and beta pre-releases. (@kvaps in https://github.com/cozystack/cozystack/pull/978)
* Commit changes in release pipelines under `github-actions <github-actions@github.com>`. (@kvaps in https://github.com/cozystack/cozystack/pull/823)
* Describe the Cozystack release workflow. (@NickVolynkin in https://github.com/cozystack/cozystack/pull/817 and https://github.com/cozystack/cozystack/pull/897)

Fixes:

* Improve the check for `versions_map` running on pull requests. (@kvaps and @klinch0 in https://github.com/cozystack/cozystack/pull/836, https://github.com/cozystack/cozystack/pull/842, and https://github.com/cozystack/cozystack/pull/845)
* If the release step was skipped on a tag, skip tests as well. (@kvaps in https://github.com/cozystack/cozystack/pull/822)
* Allow CI to cancel the previous job if a new one is scheduled. (@kvaps in https://github.com/cozystack/cozystack/pull/873)
* Use the correct version name when uploading build assets to the release page. (@kvaps in https://github.com/cozystack/cozystack/pull/876)
* Stop using `ok-to-test` label to trigger CI in pull requests. (@kvaps in https://github.com/cozystack/cozystack/pull/875)
* Do not run tests in the release building pipeline. (@kvaps in https://github.com/cozystack/cozystack/pull/882)
* Fix release branch creation. (@kvaps in https://github.com/cozystack/cozystack/pull/884)
* Reduce noise in the test logs by suppressing the `wget` progress bar. (@lllamnyp in https://github.com/cozystack/cozystack/pull/865)
* Revert "automatically trigger tests in releasing PR". (@kvaps in https://github.com/cozystack/cozystack/pull/900)
* Force-update release branch on tagged main commits. (@kvaps in https://github.com/cozystack/cozystack/pull/977)
* Show detailed errors in the `pull-request-release` workflow. (@lllamnyp in https://github.com/cozystack/cozystack/pull/992)

## Community and Maintenance

### Repository Maintenance

Added @klinch0 to CODEOWNERS. (@kvaps in https://github.com/cozystack/cozystack/pull/838)

### New Contributors

* @etoshutka made their first contribution in https://github.com/cozystack/cozystack/pull/872
* @dtrdnk made their first contribution in https://github.com/cozystack/cozystack/pull/896
* @zdenekjanda made their first contribution in https://github.com/cozystack/cozystack/pull/924
* @gwynbleidd2106 made their first contribution in https://github.com/cozystack/cozystack/pull/962

## Full Changelog

See https://github.com/cozystack/cozystack/compare/v0.30.0...v0.31.0
