watch loses resource version when watching custom object list

[juliantaylor]

kubernetes often resets watches when no changes happen (kubernetes/kubernetes#55230 (comment)), thus I have added a restart at the last resource version to my application

But the python api library resets this to zero on iteration of this loop and thus retrieves all objects again.
https://github.com/kubernetes-client/python-base/blob/83ebb9d5fdc0d46bbb2e30afcd8eec42c5da4ad1/watch/watch.py
This happens in current master using the list_cluster_custom_object function as a watch running against kubernetes 1.12.3.

Can this please be updated to respect the resource version set by the application or fix that it resets to version zero each time.

[juliantaylor]

reproducing script:

manifests:

apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
  name: mycustoms.crd.mycustom.org
spec:
  version: v1
  group: crd.mycustom.org
  names:
    kind: MyCustom
    plural: mycustoms
    singular: mycustom
  scope: Namespaced
  subresources:
    status: {}
---
apiVersion: crd.mycustom.org/v1
kind: MyCustom
metadata:
  name: customobj
  namespace: default
spec:
  data: test

import kubernetes as k8s
k8s.config.load_kube_config()
api = k8s.client.CustomObjectsApi()
group = "crd.mycustom.org"
plural = "mycustoms"
version = "v1"
items = api.list_cluster_custom_object(group=group, plural=plural, version=version)
ver = items["metadata"]["resourceVersion"]

kwargs = {}
kwargs["resource_version"] = ver
kwargs["watch"] = True
for event in k8s.watch.Watch().stream(api.list_cluster_custom_object, group, version, plural, **kwargs):
    print(event["metadata"]["resourceVersion"])

Run with printing the resource version in kubernetes/client/apis/custom_objects_api.py list_cluster_custom_object_with_http_info

[('resourceVersion', '1209375'), ('watch', True)] # correct first watch
[('resourceVersion', 0), ('watch', True)] # incorrect version on first reset

[juliantaylor]

probably a duplicate of #693

[max-rocket-internet]

probably a duplicate of what issue? You've linked back to this one. Maybe you meant #693 ?

[juliantaylor]

fixed and updated the reproducer with manifests