Implement List operations for Kubectl

[Copilot]

• Implement ListAsync method with label/field selector support
• Implement synchronous List method
• Update GenericClient to pass filter parameters to underlying API
• Add tests for List functionality
• Move List methods into existing Get files (per review feedback)
• Move List tests into KubectlTests.Get.cs (per review feedback)
• Delete separate List files (per review feedback)

Summary

This PR implements List operations for the Kubectl class, extending the KubectlGet functionality (#1684) to support listing arbitrary groups of resources with filtering.

Changes

• Kubectl.Get.cs / AsyncKubectl.Get.cs: Added List<T> and ListAsync<T> methods supporting:

  • Namespaced and cluster-scoped resource listing
  • Label selector filtering (labelSelector)
  • Field selector filtering (fieldSelector)
  • Pagination via limit and continueToken

• GenericClient.cs: Updated ListAsync and ListNamespacedAsync to pass filter parameters through to the CustomObjects API

• KubectlTests.Get.cs: E2E tests covering namespaces, pods, services, deployments, and selector filtering

Usage

var client = new Kubectl(kubernetes);

// List all namespaces
var namespaces = client.List<V1NamespaceList>();

// List pods in namespace with label selector
var pods = client.List<V1PodList>("default", labelSelector: "app=web,tier=frontend");

// Field selector
var pod = client.List<V1PodList>("default", fieldSelector: "metadata.name=my-pod");

// Pagination
var page1 = client.List<V1PodList>("default", limit: 100);
var page2 = client.List<V1PodList>("default", limit: 100, continueToken: page1.Metadata.ContinueProperty);

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Implement List operations as part of KubectlGet</issue_title>
<issue_description>In #1684 we added the ability to get arbitrary resources, we should extend this capability to match the ability of kubectl to list arbitrary groups of resources. We should include all of the potential capabilities for listing like filtering on labels or other flags.

Here's the help text from kubectl to guide this development:

kubectl get --help
Display one or many resources.

 Prints a table of the most important information about the specified resources. You can filter the list using a label
selector and the --selector flag. If the desired resource type is namespaced you will only see results in the current
namespace if you don't specify any namespace.

 By specifying the output as 'template' and providing a Go template as the value of the --template flag, you can filter
the attributes of the fetched resources.

Use "kubectl api-resources" for a complete list of supported resources.

Examples:
  # List all pods in ps output format
  kubectl get pods
  
  # List all pods in ps output format with more information (such as node name)
  kubectl get pods -o wide
  
  # List a single replication controller with specified NAME in ps output format
  kubectl get replicationcontroller web
  
  # List deployments in JSON output format, in the "v1" version of the "apps" API group
  kubectl get deployments.v1.apps -o json
  
  # List a single pod in JSON output format
  kubectl get -o json pod web-pod-13je7
  
  # List a pod identified by type and name specified in "pod.yaml" in JSON output format
  kubectl get -f pod.yaml -o json
  
  # List resources from a directory with kustomization.yaml - e.g. dir/kustomization.yaml
  kubectl get -k dir/
  
  # Return only the phase value of the specified pod
  kubectl get -o template pod/web-pod-13je7 --template={{.status.phase}}
  
  # List resource information in custom columns
  kubectl get pod test-pod -o custom-columns=CONTAINER:.spec.containers[0].name,IMAGE:.spec.containers[0].image
  
  # List all replication controllers and services together in ps output format
  kubectl get rc,services
  
  # List one or more resources by their type and names
  kubectl get rc/web service/frontend pods/web-pod-13je7
  
  # List the 'status' subresource for a single pod
  kubectl get pod web-pod-13je7 --subresource status
  
  # List all deployments in namespace 'backend'
  kubectl get deployments.apps --namespace backend
  
  # List all pods existing in all namespaces
  kubectl get pods --all-namespaces

Options:
    -A, --all-namespaces=false:
        If present, list the requested object(s) across all namespaces. Namespace in current context is ignored even
        if specified with --namespace.

    --allow-missing-template-keys=true:
        If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to
        golang and jsonpath output formats.

    --chunk-size=500:
        Return large lists in chunks rather than all at once. Pass 0 to disable. This flag is beta and may change in
        the future.

    --field-selector='':
        Selector (field query) to filter on, supports '=', '==', and '!='.(e.g. --field-selector
        key1=value1,key2=value2). The server only supports a limited number of field queries per type.

    -f, --filename=[]:
        Filename, directory, or URL to files identifying the resource to get from a server.

    --ignore-not-found=false:
        If the requested object does not exist the command will return exit code 0.

    -k, --kustomize='':
        Process the kustomization directory. This flag can't be used together with -f or -R.

    -L, --label-columns=[]:
        Accepts a comma separated list of labels that are going to be presented as columns. Names are case-sensitive.
        You can also use multiple flag options like -L label1 -L label2...

    --no-headers=false:
        When using the default or custom-column output format, don't print headers (default print headers).

    -o, --output='':
        Output format. One of: (json, yaml, name, go-template, go-template-file, template, templatefile, jsonpath,
        jsonpath-as-json, jsonpath-file, custom-columns, custom-columns-file, wide). See custom columns
        [https://kubernetes.io/docs/reference/kubectl/#custom-columns], golang template
        [http://golang.org/pkg/text/template/#pkg-overview] and jsonpath template
        [https://kubernetes.io/docs/reference/kubectl/jsonpath/].

    --output-watch-events=false:
        Output watch event objects when --watch or --watch-only is used. Existing objects are output as initial ADDED
        events.

    --raw='':
        Raw URI to request from the server.  Uses the transport specified by the kubeconfig file.

    -R, --recursive=false:
        Process the director...

</details>

- Fixes kubernetes-client/csharp#1692

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[brendandburns]

@copilot instead of creating a different Kubectl.List class can you incorporate this into the existing Kubectl.Get class, please move the tests to the test file for KubectlGet also (and thanks for writing tests!)

[Copilot]

Pull request overview

This PR extends the Kubectl client to support listing arbitrary groups of Kubernetes resources with filtering capabilities, matching the functionality of kubectl get for list operations. The implementation adds List<T> and ListAsync<T> methods that support label selectors, field selectors, and pagination.

Key Changes:

• Added List<T> and ListAsync<T> methods to Kubectl that support namespaced and cluster-scoped resource listing with label/field selector filtering and pagination
• Updated GenericClient.cs to accept filter parameters (labelSelector, fieldSelector, limit, continueToken) and pass them to the Kubernetes CustomObjects API
• Comprehensive E2E tests covering namespaces, pods, services, deployments, and various filtering scenarios

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
src/KubernetesClient.Kubectl/Beta/AsyncKubectl.List.cs	Implements async List method with support for filtering and pagination parameters
src/KubernetesClient.Kubectl/Beta/Kubectl.List.cs	Implements synchronous List method as a wrapper around AsyncKubectl
src/KubernetesClient/GenericClient.cs	Updates ListAsync and ListNamespacedAsync to accept and pass through filter parameters
tests/Kubectl.Tests/KubectlTests.List.cs	Adds comprehensive E2E tests for list functionality including label/field selectors

---

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[Copilot]

The documentation says "The type of Kubernetes resource list to get" but should say "list" instead of "get" since this is a List operation, not a Get operation. Change to: "The type of Kubernetes resource list to list (e.g., V1PodList)."

Suggested change

	/// <typeparam name="T">The type of Kubernetes resource list to get (e.g., V1PodList).</typeparam>
	/// <typeparam name="T">The type of Kubernetes resource list to list (e.g., V1PodList).</typeparam>

[Copilot]

The documentation says "The type of Kubernetes resource list to get" but should say "list" instead of "get" since this is a List operation, not a Get operation. Change to: "The type of Kubernetes resource list to list (e.g., V1PodList)."

Suggested change

	/// <typeparam name="T">The type of Kubernetes resource list to get (e.g., V1PodList).</typeparam>
	/// <typeparam name="T">The type of Kubernetes resource list to list (e.g., V1PodList).</typeparam>

[Copilot]

@copilot instead of creating a different Kubectl.List class can you incorporate this into the existing Kubectl.Get class, please move the tests to the test file for KubectlGet also (and thanks for wri...

Done in commit 78e5790. I've merged the List/ListAsync methods into the existing Kubectl.Get.cs and AsyncKubectl.Get.cs files, moved the tests into KubectlTests.Get.cs, and deleted the separate List files.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: brendandburns, Copilot

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[brendandburns]

@tg123 this is LGTM to me, feel free to merge if/when you think it's ready