feat: support kernel args management in cluster templates

[utkuozdemir]

Implement kernel args support in cluster templates.

Managing kernel args via templates is opt-in: only and only if the kernelArgs YAML key is defined on a Cluster, ControlPlane, Worker or Machine, the matching KernelArgs resource will be created/updated.

Lower levels override higher levels (Cluster -> MachineSet -> Machine).

Unlike other cluster template managed resources, they will never be destroyed, i.e, when they are removed from a template (removed completely, as in, kernelArgs key doesn't exist) or when omnictl cluster template delete is run. They instead will get updated to have the annotation omni.sidero.dev/managed-by-cluster-templates removed from them.

Add the new flag --include-kernel-args to the omnictl cluster template export command to optionally include them in the exported template. Note: when this flag is set, kernelArgs key is always included at per-machine level, not pulled up even if they are the same for all machines in a machine set or a cluster.

Update the frontend, specifically the kernel args update screen to warn the user if kernel args for that machine is managed by templates, similar to what we do for clusters.

Closes #1940.

[Copilot]

Pull request overview

This PR implements kernel arguments (kernel args) management in cluster templates, allowing users to specify kernel arguments at the Cluster, ControlPlane/Workers (MachineSet), or Machine level. The feature is opt-in and includes support for hierarchical overrides where lower levels (Machine) override higher levels (Cluster).

Key changes:

• Added kernelArgs field to cluster template models with hierarchical override support (Cluster → MachineSet → Machine)
• KernelArgs resources are never destroyed when removed from templates or during template deletion; instead, they are "orphaned" by removing the omni.sidero.dev/managed-by-cluster-templates annotation
• Added --include-kernel-args flag to omnictl cluster template export to optionally export kernel arguments in templates

Reviewed changes

Copilot reviewed 23 out of 23 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
frontend/src/views/omni/Modals/UpdateKernelArgs.vue	Refactored to use composables (useResourceGet) and added ManagedByTemplatesWarning component to alert users when kernel args are template-managed
frontend/src/views/cluster/ManagedByTemplatesWarning.vue	Generalized component to accept any resource (not just clusters) and display appropriate warnings based on resource type
frontend/src/views/omni/Clusters/Management/ClusterScale.vue	Updated prop name from cluster to resource for ManagedByTemplatesWarning component
frontend/src/views/cluster/Config/Patches.vue	Updated prop name from cluster to resource for ManagedByTemplatesWarning component
frontend/src/views/cluster/Config/PatchEdit.vue	Updated prop name from cluster to resource for ManagedByTemplatesWarning component
client/pkg/template/testdata/cluster-with-kernel-args.yaml	Test template demonstrating various kernel args inheritance scenarios (override, inheritance, empty arrays)
client/pkg/template/testdata/cluster-with-kernel-args-resources.yaml	Expected resource output for kernel args template test cases
client/pkg/template/template_test.go	Added comprehensive lifecycle test for kernel args (create, orphan, delete) ensuring they're never destroyed
client/pkg/template/template.go	Core logic for collecting actual kernel args, handling orphaning on sync/delete, and validation of resource conflicts
client/pkg/template/order.go	Added KernelArgsType to canonical resource ordering for proper resource creation/deletion sequencing
client/pkg/template/operations/testdata/export/cluster-template-with-kernel-args.yaml	Test data showing exported template with kernel args at machine level
client/pkg/template/operations/testdata/export/cluster-resources.yaml	Updated test resources to include kernel args resources with managed annotation
client/pkg/template/operations/sync.go	Refactored sync logic into reusable function shared by sync and delete operations
client/pkg/template/operations/export_test.go	Updated tests to verify export with and without kernel args based on flag
client/pkg/template/operations/export.go	Added kernel args collection and export logic with includeKernelArgs flag support
client/pkg/template/operations/delete.go	Updated to use shared sync function for consistency
client/pkg/template/internal/models/models.go	Added kernel args context fields for template translation (cluster/machineset level args)
client/pkg/template/internal/models/machineset.go	Added KernelArgs field, validation, and translation logic with inheritance from cluster level
client/pkg/template/internal/models/machine.go	Added KernelArgs field, validation, and translation logic with inheritance from machineset/cluster levels
client/pkg/template/internal/models/list.go	Updated translation context building to populate kernel args at cluster and machineset levels; exempted KernelArgs from cluster label validation
client/pkg/template/internal/models/kernelargs.go	New wrapper type for kernel args with Get/Set methods and resource builder function
client/pkg/template/internal/models/cluster.go	Added KernelArgs field and validation to Cluster model
client/pkg/omnictl/cluster/template/export.go	Added --include-kernel-args CLI flag to export command

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.