change V1Subject to RbacV1Subject in k8s.py

[merqri]

This change fix - Error: module 'kubernetes.client' has no attribute 'V1Subject'

This error occurs when an attempt is made to create a role binding. The full error looks as follows:

[E 2024-06-03 08:58:36.252 EnterpriseGatewayApp] Error occurred creating role binding for namespace 'jovyan-153ca7c1-c68f-440d-b678-f8926b48afbc': module 'kubernetes.client' has no attribute 'V1Subject'

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[kevin-bates]

Hi @merqri and @fm2022aa. I'm curious why this hasn't always been an issue. Was there a version update that triggered this? Does this only occur under certain custom role configurations? (Sorry, been out of the loop for a while and would like to better understand what prompts this change.)

[kevin-bates]

Sorry, just caught up on #1379.

Since this appears to be due to version changes, do we need to concern ourselves with breaking older installations?

@lresende - looks like you had some thoughts on this (capping client?). Does that prevent use on newer versions of k8s like 1.30 (or even 1.29)?

[lresende]

Capping the client to 1.28 would make it work for current users, but would make it fail for users that have upgraded to >= 1.29 then... Another approach would be to try to check in the code for the current version and use one or the other.

[huynhsontung]

Does that prevent use on newer versions of k8s like 1.30 (or even 1.29)?

@lresende @kevin-bates I am running Kubernetes 1.31 with EG 3.2.2 since 3.2.3 has this issue, and everything works fine as far as I can see. That said, I think this PR is backward-compatible as looking at the commit that changes V1Subject to RbacV1Subject, only the model name is updated. I don't think this is a breaking change in the API, as I couldn't find any mentions of it in the v29 changelog.

[lresende]

@merqri how about we do something like:

+def get_subject_class():
+    """
+    Returns the appropriate Subject class based on the kubernetes client version.
+
+    In kubernetes-client, V1Subject was renamed to RbacV1Subject.
+    This function returns the appropriate class based on the installed version.
+    """
+    # Check if V1Subject exists in the client
+    if hasattr(client, 'V1Subject'):
+        logging.debug("Using client.V1Subject for Kubernetes client version: %s", kubernetes.__version__)
+        return client.V1Subject
+    # Fall back to RbacV1Subject for older versions
+    logging.debug("Using client.RbacV1Subject for Kubernetes client version: %s", kubernetes.__version__)
+    return client.RbacV1Subject
+

and then something like:

-        binding_subjects = client.RbacV1Subject(
+        # Use the appropriate Subject class based on kubernetes client version
+        SubjectClass = get_subject_class()
+        binding_subjects = SubjectClass(
             api_group="", kind="ServiceAccount", name=service_account_name, namespace=namespace
         )

if you are ok I can push an update to your pr.