## What this PR does
This PR refactors the apiserver REST handlers to use typed objects
(`appsv1alpha1.Application`) instead of `unstructured.Unstructured`,
eliminating
the need for runtime conversions and simplifying the codebase.
Additionally, it fixes an issue where `UnstructuredList` objects were
using
the first registered kind from `typeToGVK` instead of the kind from the
object's field when multiple kinds are registered with the same Go type.
This is a more comprehensive fix for the problem addressed in
https://github.com/cozystack/cozystack/pull/1630, which was reverted in
https://github.com/cozystack/cozystack/pull/1677.
The fix includes the upstream fix from kubernetes/kubernetes#135537,
which enables short-circuit path for `UnstructuredList` similar to
regular
`Unstructured` objects, using GVK from the object field instead of
`typeToGVK`.
### Changes
- Refactored `rest.go` handlers to use typed `Application` objects
- Removed `unstructured.Unstructured` conversions
- Fixed `UnstructuredList` GVK handling
- Updated dependencies in `go.mod`/`go.sum`
- Added e2e test for OpenAPI validation
- Updated Dockerfile
### Release note
```release-note
[apps] Refactor apiserver to use typed objects and fix UnstructuredList GVK handling
This change refactors the apiserver REST handlers to use typed Application objects instead of unstructured.Unstructured, eliminating runtime conversions and simplifying the codebase. Additionally, it fixes an issue where UnstructuredList objects were incorrectly using the first registered kind from typeToGVK instead of the kind from the object's field when multiple kinds are registered with the same Go type. This fix includes the upstream fix from kubernetes/kubernetes#135537.
```
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Chores**
* Added a module replacement in dependency configuration to ensure
reproducible builds.
* **Refactor**
* REST internals now use strongly-typed Application and TenantModule
resources and return typed API objects with consistent metadata.
* **Tests**
* Strengthened end-to-end checks for resource kinds and added a
create/delete namespace scenario.
<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
## What this PR does
This patch fixes an issue with the Cozystack API server that causes it
to respond with the first registered dynamic list kind when listing
dynamic resources. E.g., when running `k get postgreses`, the raw JSON
response from the cozystack API would be
```json
{
"apiVersion":"apps.cozystack.io/v1alpha1",
"kind":"BootBoxList",
"items": [
{
"apiVersion":"apps.cozystack.io/v1alpha1",
"kind":"Postgres",
...
},
...
],
...
}
```
The root cause is the way the `Typer` interface is implemented for the
`runtime.Scheme` where the dynamic types are registered. Since the base
type for all dynamic types is a `&cozyv1alpha1.Application{}`, all types
are registered under the same key and the `Typer` defaults to the first
`GroupVersionKind` that was registered. Only when a correctly formed
`&unstructured.Unstructured{}` is returned by the API, is this resolving
logic circumvented and the `GroupVersionKind` is instead inferred from
the fields of the returned object. Even an `UnstructuredList` is not
acceptable as a return type, instead the `items` key should be directly
set on the underlying `map[string]interface{}`.
This patch implements the changes detailed above. Additionally, the
following features, fixes, and improvements are added:
* Makefile targets to build and run the Cozystack API locally, against a
Kubernetes server in the environment's KUBECONFIG. Debugging with
Delve is also supported.
* CI tests are added to verify the new changes.
* A bug in the registration of the corev1alpha1 types is fixed.
* Updated the `ConvertToTable` function to properly handle list kinds
which might be of the `&unstructured.Unstructured{}` concrete type
(not an `UnstructuredList`).
* The scheme used by the API server's Client and WatchClient is
separated from the scheme used to serve dynamic types.
* The client config for reading the runtime configuration now uses the
controller-runtime, which handles flags and environment variables
properly, unlike `clientcmd`.
### Release note
```release-note
[api] Fix incorrect list kind for list requests to the Cozystack API for
dynamic resources. Add Makefile targets for local testing. Minor schema
building improvements.
```
Signed-off-by: Timofei Larkin <lllamnyp@gmail.com>
Andrei Kvapil