[receiver/k8sobjectsreceiver] k8sobject receiver support leader election

[Frapschen]

Description

As #38426 move the k8sleaderelector from development to alpha, we can use it in k8sobjectsreceiver.

[Frapschen]

I have test the code in my enviroment. I use this config:

exporters:
  debug: {}
extensions:
  k8s_leader_elector/k8sobjects:
    auth_type: kubeConfig
    context: cluster-bm-admin@cluster-bm
    lease_name: local-test-k8sobjects
    lease_namespace: default
processors:
  batch: {}
receivers:
  k8sobjects:
    auth_type: kubeConfig
    context: cluster-bm-admin@cluster-bm
    k8s_leader_elector: k8s_leader_elector/k8sobjects
    objects:
      - name: events
        mode: pull
        group: events.k8s.io/v1
        interval: 10s
service:
  telemetry:
    logs:
      level: info
    metrics:
      address: 0.0.0.0:1233
  extensions:
    - k8s_leader_elector/k8sobjects
  pipelines:
    logs:
      exporters:
#        - file
        - debug
      processors:
        - batch
      receivers:
        - k8sobjects

test case 1: start two collector instances with leader electon

we can see only the first collector successfully acquired lease and start pull k8s event data

test case 1: The lease resource was accidentally deleted

The first collector print error logs but stil get lease and continue pull event from k8s

test case 1: shutdown the first and wait 3s to restart

The second collector successfully acquired the lease 20 seconds after the first collector shut down.

[atoulme]

you might like to log that error.

[atoulme]

please check the casting to avoid panics.

[atoulme]

Please resolve conflicts and add tests. It would be ideal to have a unit test that covers an election with receivers joining and leaving.

[Frapschen]

@atoulme A normal unit test can‘t achieve your suggestion. I will try to add a new e2e test to address this.

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[rakesh-garimella]

Hi @Frapschen have a look at this unit test may be it gives some inspiration: https://github.com/open-telemetry/opentelemetry-collector-contrib/pull/38429/files#diff-166c09ecb8e6d1da525f46005a9a3f6a8f5a4870b74f60a5e0e9a3adc7b97b60R96 ?

[Frapschen]

https://github.com/open-telemetry/opentelemetry-collector-contrib/pull/38429/files#diff-166c09ecb8e6d1da525f46005a9a3f6a8f5a4870b74f60a5e0e9a3adc7b97b60R96

Thank your, that's help a lot