1. Proposed title of this feature request
Enable ingress backend health logging

2. What is the nature and description of the request?
Customer is seeing server backend health check logs at their Native HAProxy.
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[WARNING] (8) : Server entsysgit-d_ep/gitlabinst is DOWN, reason: Layer6 invalid response, info: "SSL handshake failure", check duration: 184ms. 0 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.
[ALERT] (8) : backend 'entsysgit-d_ep' has no server available!
[WARNING] (8) : Server entsysgit-d_ep/gitlabinst is UP, reason: Layer7 check passed, code: 200, check duration: 10ms. 1 active and 0 backup servers online. 0 sessions requeued, 0 total in queue.
[WARNING] (8) : Server entsysgit-d_ep/gitlabinst is DOWN, reason: Layer6 invalid response, info: "SSL handshake failure", check duration: 185ms. 0 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.
{{[ALERT] (8) : backend 'entsysgit-d_ep' has no server available!
[WARNING] (8) : Server entsysgit-d_ep/gitlabinst is UP, reason: Layer7 check passed, code: 200, check duration: 45ms. 1 active and 0 backup servers online. 0 sessions requeued, 0 total in queue.}}

~~~

Such type of logs cannot be seen at router pod logs. 
Only access logging can be enabled at ingress controller. 
As of now, we cannot enable such type of backend health check logs.

Additional info: 
With enabling and adding "option  log-health-checks" in HAProxy config would enable such logs. But default HAProxy config does not include it. Also, there is no option for now to add this using ingresscontroller.  

3. Why does the customer need this? (List the business requirements here)

They want to assure developers that issues they are experiencing are not down to the pod being marked offline.

4. List any affected packages or components.
OpenShift ingress/ router pods/ Ingresscontroller/