how to get apiGroupList use kubernetes-client?

[gewei2000]

how to get apiGroupList use kubernetes-client?

[rohanKanojia]

Do you mean ApiService? If yes, you can get them like this:

try (KubernetesClient client = new DefaultKubernetesClient()) {
    client.apiServices().list().getItems().stream()
            .map(APIService::getMetadata)
            .map(ObjectMeta::getName)
            .forEach(System.out::println);
}

[gewei2000]

Do you mean ApiService? If yes, you can get them like this:

try (KubernetesClient client = new DefaultKubernetesClient()) {
    client.apiServices().list().getItems().stream()
            .map(APIService::getMetadata)
            .map(ObjectMeta::getName)
            .forEach(System.out::println);
}

io.fabric8.kubernetes.api.model.APIGroupList，this model

[gewei2000]

Do you mean ApiService? If yes, you can get them like this:

try (KubernetesClient client = new DefaultKubernetesClient()) {
    client.apiServices().list().getItems().stream()
            .map(APIService::getMetadata)
            .map(ObjectMeta::getName)
            .forEach(System.out::println);
}

I want to get preferred version, but I don't how to get APIGroupList use this client

[rohanKanojia]

@gewei2000 : ohk, we're missing support for this. We don't have DSL support for it yet. We'll provide it's support before upcoming release. Internally we're using APIGroup by manually hitting using okhttp:

kubernetes-client/openshift-client/src/main/java/io/fabric8/openshift/client/OpenshiftAdapterSupport.java

Lines 70 to 76 in 8932e4d

	OkHttpClient httpClient = clientWithOpenShiftOAuthInterceptor(((BaseClient)client).getHttpClient(), config);
	try {
	Request.Builder requestBuilder = new Request.Builder()
	.get()
	.url(URLUtils.join(masterUrl.toString(), APIS));
	Response response = httpClient.newCall(requestBuilder.build()).execute();
	APIGroupList apiGroupList = Serialization.unmarshal(response.body().string(), APIGroupList.class);

[manusa]

This would be really useful to get the cluster available API groups and API resources:

$ kubectl proxy --port=8081
$ curl localhost:8081/apis
# For any of the available groups
$ curl localhost:8081/apis/apps/v1

The response for the APIResourceList provides the required information to interact with any group/resource in K8s. This is really useful when we need to deal with Custom Resources and we don't have a definition (CRD) for them.
An improvement for the GenericKubernetesResource operations DSL method, might include querying these endpoints and then retrieving the necessary data to infer the plural and scope of the resource.

Relates to #2929

[shawkins]

I could take this for 5.8. ApiGroup is now annotated appropriately, so it will just take a couple of other changes to expose it via the dsl.

[manusa]

Take into account that this is not really a resource, just an additional HTTP endpoint exposed by Kubernetes.

So not the same operations that apply to the rest of resources apply for this. It makes sense in the scope of an API group (e.g. client.apps() or client.network()).

So if API groups and versions could be interfaced appropriately should be easy.

[manusa]

But maybe as a first approach, something to be able to request information for a specific group, version is what we really want here.

[shawkins]

Sure, I was initially thinking that it would be something like getting a handler for the ApiGroup / ApiGroupList and exposing only the list operation. But looking at it more, that doesn't work so well with the expectations in base operation. It would be simpler to move the isAdaptable logic into a
ApiGroupLIst KubernetesClient.getApiGroups() method. and/or support getting a single one as well.

[manusa]

ApiGroupLIst KubernetesClient.getApiGroups() method. and/or support getting a single one as well.

Yes, so basically we are looking at what was exposed in my comment, get a list of the available groups and then for each group, be able to retrieve the available resources with their required info (plural, scope, etc.)

These new methods can be then used by the GenericResource loader to perform operations on any available resource (as discussed #3392 (comment) & #3392 (comment)).

Some pseudo-logic:

1. Check in client cache if a given group exists

• If it doesn't, reload group cache by using kubernetesClient.getApiGroups() (how to get apiGroupList use kubernetes-client?  #3294)

2. Check in client cache if a given resource (group+version+kind) exists

• If it doesn't, reload resource cahce by using kubernetesClient.getApiResources(ApiGroup) (Support for fetching APIResourceList #3303)

3. Use the information from the cached ApiResource(s) to determine the required plural and scope for the GenericKubernetesResourceOperationsImpl