+++ This bug was initially created as a clone of Bug #1828382 +++
Description of problem:
Load balancers (both internal and external) for kube-apiserver should use /readyz for back-end health check.
After scanning the github repo, we found the following platforms do not use /readyz for backend health check.
Please investigate the following, not sure if it needs to be addressed
The above health checks use default TCP rule which breaks graceful termination. When the apiserver receives a KILL signal /readyz will start reporting failure. This gives the load balancer a chance to detect an instance that is rolling out and take appropriate action.
We should use AWS lb rules as a reference for consistency - https://github.com/openshift/installer/blob/master/data/data/aws/vpc/master-elb.tf#L87
healthy_threshold = 2
unhealthy_threshold = 2
interval = 10
port = 6443
protocol = "HTTPS"
path = "/readyz"
Version-Release number of the following components:
Steps to Reproduce:
1. Run an upgrade job on the specified infrastructure.
You will see that the load balancer is sending request to an apiserver while it's down.
An example: https://prow.svc.ci.openshift.org/view/gcs/origin-ci-test/logs/release-openshift-ocp-installer-e2e-azure-serial-4.4/1542
Apr 26 21:45:14.063: INFO: Unexpected error listing nodes: Get https://api.ci-op-hvqc8pgw-0ba00.ci.azure.devcluster.openshift.com:6443/api/v1/nodes?fieldSelector=spec.unschedulable%3Dfalse&resourceVersion=0: dial tcp 188.8.131.52:6443: connect: connection refused
The load balancer should identify the kube-apiserer instance that is being rolled out in time and forward requests to another instance that is serving. Ideally, we should not see any "dial tcp 184.108.40.206:6443: connect: connection refused" error while kube-apiserver is being rolled out.
Bug 1828382 handled installer-provisioned Azure. This clone is for the user-provisioned Azure recommendations. Dropping severity down to medium, because user-provisioned recommendations are suggesting approaches, not telling the user what they should be doing without thinking.
Won't be able to get to it this sprint.
Confirmed both internal and external loadbalancers are using http/https and the /readyz endpoint in UPI Azure using 4.5.0-0.nightly-2020-06-10-224736
*** Bug 1856729 has been marked as a duplicate of this bug. ***
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (OpenShift Container Platform 4.6 GA Images), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.