wangyang0918 opened a new pull request #13644:
URL: https://github.com/apache/flink/pull/13644
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## What is the purpose of the change
This is the first PR of
[FLIP-144](https://cwiki.apache.org/confluence/display/FLINK/FLIP-143%3A+Unified+Sink+API),
adding the `KubernetesLeaderElectionService` and
`KubernetesLeaderRetrievalService`. You could find more design details in the
FLIP doc.
In this PR, we add some necessary interfaces for the ConfigMap operations.
The most important one is `FlinkKubeClient#checkAndUpdateConfigMap`. Benefit
from [resource
version](https://kubernetes.io/docs/reference/using-api/api-concepts/#resource-versions)
and combined with `FlinkKubeClient#getConfigMap(String)`, we could perform a
get-check-and-update transactional operation. Since concurrent modification
could happen on a same ConfigMap, the update operation may fail. We need to
retry internally. The max retry attempts could be configured via `
org.apache.flink.kubernetes.configuration.KubernetesConfigOptions#KUBERNETES_MAX_RETRY_ATTEMPTS`.
## Brief change log
* edad84f4f497a7a987a05bc41ceb3e75e58ec37a Use a more generic
WatchCallbackHandler to replace PodCallbackHandler
* 02cf691f7deda6cf128a0fbd2bb0cdf6baf7390e Add public interfaces for
ConfigMap operations(e.g. create/get/update/delete)
* 8f868c13655b9d11149bf7ba6b2803c3ffff1391 Extract some common logics from
ZooKeeperLeaderElectionService to AbstractLeaderElectionService
* c32eeb3b2a45a5bb349394f9651c2e54b80bbfc3 Implement LeaderElectionService
and LeaderRetrievalService based on Kubernetes API
## Verifying this change
* Add unit tests for Fabric8KubeClient new added interfaces
* Add unit tests `KubernetesLeaderElectionServiceTest` and
`KubernetesLeaderRetrievalServiceTest` for LeaderElection and LeaderRetrieval
## Does this pull request potentially affect one of the following parts:
- Dependencies (does it add or upgrade a dependency): (yes / **no**)
- The public API, i.e., is any changed class annotated with
`@Public(Evolving)`: (yes / **no**)
- The serializers: (yes / **no** / don't know)
- The runtime per-record code paths (performance sensitive): (yes / **no**
/ don't know)
- Anything that affects deployment or recovery: JobManager (and its
components), Checkpointing, Kubernetes/Yarn/Mesos, ZooKeeper: (**yes** / no /
don't know)
- The S3 file system connector: (yes / **no** / don't know)
## Documentation
- Does this pull request introduce a new feature? (**yes** / no)
- If yes, how is the feature documented? (will add doc in a separate
ticket)
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