Bug 1660598

Follow above steps, this bug can be easily reproduced in v3.11.43

more testing results below:

1. create route with a path and update the host several times, cannot reproduce
   # oc expose svc service-unsecure --name=testpath --hostname=abc.test.example.com --path=/test
   # oc patch route testpath -p '{"spec":{"host":"abc.testpath.example.com"}}'
   # oc patch route testpath -p '{"spec":{"host":"abc.test.example.com"}}'
   # oc patch route testpath -p '{"spec":{"host":"abc.testpath.example.com"}}'
   # oc patch route testpath -p '{"spec":{"host":"abc.test.example.com"}}'
   .......

2. create route without path and update the host several times, cannot reproduce
   # oc expose svc service-unsecure --name=tt --hostname=abc.tt.example.com
   # oc patch route tt -p '{"spec":{"host":"abc.ttnopath.example.com"}}'
   # oc patch route tt -p '{"spec":{"host":"abc.tt.example.com"}}'
   # oc patch route tt -p '{"spec":{"host":"abc.ttnopath.example.com"}}'
   # oc patch route tt -p '{"spec":{"host":"abc.tt.example.com"}}'
   ......

3. create route with a path and update the path several times, the issue occurred at the 3rd update. 
   # oc expose svc service-unsecure --name=testpath --hostname=abc.test.example.com --path=/test
   # oc patch route testpath -p '{"spec":{"path":"/path"}}'
   # oc patch route testpath -p '{"spec":{"path":"/test"}}'
   # oc patch route testpath -p '{"spec":{"path":"/path"}}'            ### -->>> issue here

Version: v3.11.43

one more testing:

create a route and update the path to different value each time, no issue;
update the path to the begging value when the route was created, no issue; 
if update path to any value has been used, then issue occurred.

test steps:
# oc expose svc service-unsecure --name=tt --hostname=abc.tt.example.com         ### no path specified
# oc patch route tt -p '{"spec":{"path":"/one"}}'
# oc patch route tt -p '{"spec":{"path":"/two"}}'
# oc patch route tt -p '{"spec":{"path":"/three"}}'
# oc patch route tt -p '{"spec":{"path":"/four"}}'
# oc patch route tt -p '{"spec":{"path":"/five"}}'
# oc patch route tt -p '{"spec":{"path":""}}'           ### update to beginning value, no issue
# oc patch route tt -p '{"spec":{"path":"/six"}}'
# oc patch route tt -p '{"spec":{"path":"/two"}}'       ### issue occurred, show "HostAlreadyClaimed" when "oc get route"
# oc patch route tt -p '{"spec":{"path":""}}'           ### update to beginning value,  "HostAlreadyClaimed" is gone

Thanks for the reproducers. We'll investigate.

I've made some significant progress on a root cause diagnosis and will provide another update tomorrow (Jan. 22).

*** Bug 1663423 has been marked as a duplicate of this bug. ***

Just a brief update:

We've made more progress today understanding the root cause of the problem. The bug is essentially due to an internal data consistency issue in the route controller process. Unfortunately, we don't yet have the level of clarity we need to:

1. Comprehensively describe the exact failure modes
2. Provide a reliable fix

We'll need more time to follow our current lines of investigation to their conclusions. Progress will pick up again tomorrow (EST time).

Proposed fix: https://github.com/openshift/router/pull/9

verified with atomic-openshift-3.11.82-1.git.0.08bc31b.el7 and the issue has been fixed.

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, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2019:0326

*** Bug 1723527 has been marked as a duplicate of this bug. ***