After using namespaced kubernetes client, we will not need to always set the namespace when creating kubernetes resources(e.g. deployment, pods, configmap, watch, etc.).

Address comments: Update the unit test to verify the configmap watch is created in appropriate namespace

This closes #14570.

[FLINK-20650][k8s] Remove "native-k8s" command and add bash wrapper for JobManager and TaskManager container args

The "native-k8s" command has been deprecated. Flink should use the pass-through mode. Note that Flink needs to add a "bash -c" wrapper so that the environment variables could be expanded when executing in the "docker-entrypoint.sh".

The corresponding PR in flink-docker is https://github.com/apache/flink-docker/pull/49.

This closes #14419

This closes #14416.

This closes #14157.

Only lowercase alphanumeric characters, "-" or "." are allowed.

This closes #14132.

This closes #13871.

This closes #13864.

[FLINK-19542][k8s] Implement LeaderElectionService and LeaderRetrievalService based on Kubernetes API

This closes #13644.

[FLINK-19662][container][runtime][kubernetes][mesos][yarn] Moved ClusterEntrypointUtils into ClusterEntrypoint package.

[FLINK-19662][runtime][kubernetes][yarn][dist] Added dynamic parameters to BashJavaUtils' JobManager argument extraction. Additionally, the Kubernetes and Yarn deployment were extended accordingly.

The parameters are returned using the newly introduced global environment variable DYNAMIC_PARAMETERS.

Before, it was up to the CustomCommandLine implementation whether any
Configuration was passed through from the flink-conf.yaml or wherever
the base Configuration came from.

Now, we make the flow of the Configuration explicit in
CliFrontend.getEffectiveConfiguration(). Instead of relying on the
Configuration we get from the CustomCommandLine we ask the
CustomCommandLine to materialize its settings and add them manually to
an effective Configuration that the CliFrontend controls.

This removes the Configuration parameter from CustomCommandLines that
don't need it anymore, such as DefaultCLI, which means we also have to
touch tests.

This adds a new integration test in CliFrontendITCase that verifies
correct parameter passing and also verifies that command line arguments
override base settings.

This closes #13755.

This closes #13765.

[FLINK-18971][kubernetes] Support to mount kerberos conf as ConfigMap and Keytab as Secrete in Kubernetes

This closes #13313.

This closes #13322.

This closes #13448.

This closes #13263.

This closes #13186.

This closes #12899.