Aleksei Sviridkin
dff5f8d19a
## What this PR does Replace the ephemeral `emptyDisk` volume on tenant Kubernetes worker VMs with persistent PVC-backed storage via KubeVirt `dataVolumeTemplates`. Previously, kubelet certificates, kubeconfig, and containerd state were lost on VM reboot, causing the node to fall out of the tenant cluster. **Changes:** - Rename `ephemeralStorage` field to `diskSize` in NodeGroup configuration - Replace `emptyDisk` volume with `dataVolumeTemplates` using CDI blank source - Add `cdi.kubevirt.io/storage.usePopulator: "false"` annotation to work around CDI volume population issues with LINSTOR CSI - Add optional per-nodeGroup `storageClass` field (defaults to cluster default) - Set fixed 2Gi ephemeral-storage resource for virt-launcher pod - Rename internal mount paths from `/ephemeral` to `/persistent` - Add helm unit tests (`cluster_test.yaml`) covering dataVolumeTemplates defaults, custom disk size, storageClass presence/absence, fixed ephemeral-storage, disk name consistency, and CDI populator annotation - Quote storage values in templates (`diskSize`, `storageClassName`) for Helm correctness - Guard bind-mount commands with `mountpoint -q` checks and create target directories to handle fresh images and cloud-init retries - Set `blockSize.matchVolume` on worker node disks for automatic block size detection, fixing DRBD 4Kn compatibility with QEMU **Known gotchas:** - CDI volume population (prime PVC rebind) causes `ClaimMisbound` errors with LINSTOR CSI driver, regardless of StorageClass (`replicated` or `local`). The `usePopulator: false` annotation switches to the legacy import path which works correctly. This is a known CDI issue documented in [kubevirt/containerized-data-importer#3146](https://github.com/kubevirt/containerized-data-importer/issues/3146). - The `replicated` StorageClass with DRBD `suspend-io` quorum policy can cause transient VM IO errors during LINSTOR satellite restarts (quorum loss). The `local` StorageClass is recommended for worker node disks. When `storageClass` is not specified in a nodeGroup, the cluster default StorageClass is used. - Existing clusters will trigger a rolling replacement of all worker nodes on upgrade due to changed KubevirtMachineTemplate hash. - DRBD volumes use 4096-byte logical sectors (`block-size 4096`). Without explicit block size configuration, QEMU defaults to 512-byte sectors, causing immediate IO errors and VM pause. The `blockSize.matchVolume` setting in the disk spec ensures KubeVirt auto-detects the correct sector size from the volume. **Tested on a live cluster:** - Verified DataVolume provisioning with `local` StorageClass - Verified nodes join the tenant cluster and reach Ready state - Verified node survives VM reboot (pod deletion) and returns to Ready with the same Node object, reusing kubelet certificates from persistent disk ### Screenshots N/A — no UI changes. ### Release note ```release-note feat(kubernetes)!: replace ephemeral emptyDisk with persistent storage for worker nodes Worker node VMs now use persistent PVC-backed disks instead of ephemeral emptyDisk volumes. Kubelet certificates, kubeconfig, and containerd state survive VM reboots, preventing nodes from falling out of the tenant cluster. BREAKING CHANGE: The `ephemeralStorage` field in nodeGroups has been renamed to `diskSize`. A new optional `storageClass` field allows per-nodeGroup storage class selection. Users must update their values overrides accordingly. Worker node disks now use `blockSize.matchVolume` to automatically detect the underlying volume's sector size, ensuring compatibility with DRBD-backed storage classes that use 4096-byte logical sectors. ``` <!-- This is an auto-generated comment: release notes by coderabbit.ai --> ## Summary by CodeRabbit * **New Features** * Optional storageClass parameter to select storage class for worker node persistent disks (defaults to cluster default). * Makefile test target added to run Helm unit tests for the chart. * **Configuration Changes** * Worker node storage parameter renamed from ephemeralStorage to diskSize (default: 20Gi). * Kubelet/containerd state moved to persistent disk paths and node ephemeral-storage accounting fixed to 2Gi; disk provisioning aligns block sizing with backing volumes. * **Documentation** * Updated docs and chart/schema to reflect the persistent disk model and new fields. <!-- end of auto-generated comment: release notes by coderabbit.ai -->
Cozystack
Cozystack is a free platform and framework for building clouds.
Cozystack is a CNCF Sandbox Level Project that was originally built and sponsored by Ænix.
With Cozystack, you can transform a bunch of servers into an intelligent system with a simple REST API for spawning Kubernetes clusters, Database-as-a-Service, virtual machines, load balancers, HTTP caching services, and other services with ease.
Use Cozystack to build your own cloud or provide a cost-effective development environment.
Use-Cases
-
Using Cozystack to build a public cloud
You can use Cozystack as a backend for a public cloud -
Using Cozystack to build a private cloud
You can use Cozystack as a platform to build a private cloud powered by Infrastructure-as-Code approach -
Using Cozystack as a Kubernetes distribution
You can use Cozystack as a Kubernetes distribution for Bare Metal
Documentation
The documentation is located on the cozystack.io website.
Read the Getting Started section for a quick start.
If you encounter any difficulties, start with the troubleshooting guide and work your way through the process that we've outlined.
Versioning
Versioning adheres to the Semantic Versioning principles.
A full list of the available releases is available in the GitHub repository's Release section.
Contributions
Contributions are highly appreciated and very welcomed!
In case of bugs, please check if the issue has already been opened by checking the GitHub Issues section. If it isn't, you can open a new one. A detailed report will help us replicate it, assess it, and work on a fix.
You can express your intention to on the fix on your own. Commits are used to generate the changelog, and their author will be referenced in it.
If you have Feature Requests please use the Discussion's Feature Request section.
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License
Cozystack is licensed under Apache 2.0.
The code is provided as-is with no warranties.
Commercial Support
A list of companies providing commercial support for this project can be found on official site.