ETCD-668: add etcd-backup-server readiness probe

[Elbehery]

This PR adds readiness probe to the etcd-backup-server container.

resolves https://issues.redhat.com/browse/ETCD-668

[openshift-ci-robot]

@Elbehery: This pull request references ETCD-668 which is a valid jira issue.

In response to [this](https://github.com/openshift/cluster-etcd-operator/pull/1335): >This PR adds *readiness probe* to the `etcd-backup-server` container. > >resolves https://issues.redhat.com/browse/ETCD-668 Instructions for interacting with me using PR comments are available [here](https://prow.ci.openshift.org/command-help?repo=openshift%2Fcluster-etcd-operator). If you have questions or suggestions related to my behavior, please file an issue against the [openshift-eng/jira-lifecycle-plugin](https://github.com/openshift-eng/jira-lifecycle-plugin/issues/new) repository.

[openshift-ci[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Elbehery

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[Elbehery]

/retest-required

[Elbehery]

The current implementation is not working, since the liveness probes fails as long as the etcd-backup-server is disabled, which is the default case .. Hence, the installer pod will always fails

{Operator degraded (StaticPods_Error):

 StaticPodsDegraded: pod/etcd-ip-10-0-26-178.us-east-2.compute.internal container "etcd-backup-server" is waiting: 

CrashLoopBackOff: back-off 5m0s restarting failed container=etcd-backup-server pod=etcd-ip-10-0-26-178.us-east-2.compute.internal_openshift-etcd(c69a15af465abb74b4abb4eb99a96b1c) 

StaticPodsDegraded: pod/etcd-ip-10-0-64-201.us-east-2.compute.internal container "etcd-backup-server" is waiting: 

CrashLoopBackOff: back-off 5m0s restarting failed container=etcd-backup-server pod=etcd-ip-10-0-64-201.us-east-2.compute.internal_openshift-etcd(03e9ef5bb03d08bf7a8b34889b9d2658)  Operator degraded (StaticPods_Error): 

StaticPodsDegraded: pod/etcd-ip-10-0-26-178.us-east-2.compute.internal container "etcd-backup-server" is waiting: 

CrashLoopBackOff: back-off 5m0s restarting failed container=etcd-backup-server pod=etcd-ip-10-0-26-178.us-east-2.compute.internal_openshift-etcd(c69a15af465abb74b4abb4eb99a96b1c)

 StaticPodsDegraded: pod/etcd-ip-10-0-64-201.us-east-2.compute.internal container "etcd-backup-server" is waiting: 

CrashLoopBackOff: back-off 5m0s restarting failed container=etcd-backup-server pod=etcd-ip-10-0-64-201.us-east-2.compute.internal_openshift-etcd(03e9ef5bb03d08bf7a8b34889b9d2658)}

see prow

To mitigate this issue, the liveness probe should be added to the staticPodManifest along side the BackupVars ...

[Elbehery]

/label tide/merge-method-squash

[openshift-ci[bot]]

@Elbehery: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/e2e-metal-ovn-ha-cert-rotation-shutdown	5095fcb0b9fa2b341c7295f3b5639b9742d0fb97	link	false	/test e2e-metal-ovn-ha-cert-rotation-shutdown
ci/prow/e2e-aws-etcd-certrotation	5095fcb0b9fa2b341c7295f3b5639b9742d0fb97	link	false	/test e2e-aws-etcd-certrotation
ci/prow/e2e-aws-etcd-recovery	5095fcb0b9fa2b341c7295f3b5639b9742d0fb97	link	false	/test e2e-aws-etcd-recovery
ci/prow/e2e-metal-ovn-sno-cert-rotation-shutdown	5095fcb0b9fa2b341c7295f3b5639b9742d0fb97	link	false	/test e2e-metal-ovn-sno-cert-rotation-shutdown

Full PR test history. Your PR dashboard.

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