out_rdkafka2: enable idempotency for kafka producers

[dipendra-singh]

Which issue(s) this PR fixes:
None.

What this PR does / why we need it:
In order to enable Idempotency for kafka producers, rdkafka allowes us to enable this. (here)

Docs Changes:
README.md : Added to usage template for better visibility.

Release Note:
Same as the title.

[ashie]

Any rdkafka options can be set by rdkafka_options parameter.
e.g.)

<match tag>
  @type rdkafka2
   rdkafka_options {                                                                                                                                        
     "enable.idempotence" : true
   }
   ....
</match>

Is there any reason to add a new specific parameter for idempotence?

[dipendra-singh]

@ashie To keep the consistency between this and other plugins. One needs to explore rdkafka options to have similar features to that of other plugins.

[ashie]

Ah, I see. Thanks for clarification.
It seems reasonable.

fluent-plugin-kafka/lib/fluent/plugin/out_kafka2.rb

Line 37 in ea0f10a

config_param :idempotent, :bool, :default => false, :desc => 'Enable idempotent producer'

[dipendra-singh]

hey @ashie
Can we close this?

[github-actions]

This PR has been automatically marked as stale because it has been open 90 days with no activity. Remove stale label or comment or this PR will be closed in 30 days

[ashie]

Thanks for your contribution!
I'm sorry for delay merging this.