Add allNamespaces() method to KubectlGet

[Copilot]

KubectlGet lacks the --all-namespaces (-A) flag from kubectl get, making it impossible to explicitly request cluster-wide listing.

Changes

• Add allNamespaces() fluent method to KubectlGet
• When set, overrides any namespace setting and performs cluster-wide listing
• Add unit tests for the new flag and its precedence over namespace()

Usage

// Equivalent to: kubectl get pods --all-namespaces
List<V1Pod> pods = Kubectl.get(V1Pod.class)
    .apiClient(apiClient)
    .allNamespaces()
    .execute();

// allNamespaces() takes precedence over namespace()
List<V1Pod> pods = Kubectl.get(V1Pod.class)
    .namespace("default")
    .allNamespaces()  // ignores "default", lists all
    .execute();

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• groovy.jfrog.io
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.11/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.11/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.11 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.11/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/java/java org.codehaus.plexus.classworlds.launcher.Launcher -pl extended spotless:check (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>KubectlGet doesn't fully match the CLI implementation</issue_title>
<issue_description>The current implementation of KubectlGet doesn't fully match the kubectl implementation.

For context, here is the help text for kubectl get:

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 directory used in -f, --filename recursively. Useful when you want to manage related manifests
        organized within the same directory.

    -l, --selector='':
        Selector (label query) to filter on, supports '=', '==', and '!='.(...

</details>

- Fixes kubernetes-client/java#4445

<!-- START COPILOT CODING AGENT TIPS -->
---

✨ Let Copilot coding agent [set things up for you](https://github.com/kubernetes-client/java/issues/new?title=✨+Set+up+Copilot+instructions&body=Configure%20instructions%20for%20this%20repository%20as%20documented%20in%20%5BBest%20practices%20for%20Copilot%20coding%20agent%20in%20your%20repository%5D%28https://gh.io/copilot-coding-agent-tips%29%2E%0A%0A%3COnboard%20this%20repo%3E&assignees=copilot) — coding agent works faster and does higher quality work when set up for your repo.

[brendandburns]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

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

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [brendandburns]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment