Comment 4 for bug 1946280

Reviewed: https://review.opendev.org/c/openstack/charm-ceph-radosgw/+/817582
Committed: https://opendev.org/openstack/charm-ceph-radosgw/commit/31a4584169c1c78e59dc505de4163d528d1cae0a
Submitter: "Zuul (22348)"
Branch: master

commit 31a4584169c1c78e59dc505de4163d528d1cae0a
Author: Cornellius Metto <email address hidden>
Date: Thu Nov 11 16:03:13 2021 +0000

    Enable HAProxy HTTP Health Checks

    Ceph radosgw supports [0] the swift health check endpoint
    "/swift/healthcheck". This change adds the haproxy
    configuration [1] necessary to take the response of "GET
    /swift/healthcheck" into account when determining the health
    of a radosgw service.

    For testing, I verified that:
    - HAProxy starts and responds to requests normally with this
      configuration.
    - Servers with status != 2xx or 3xx are removed from the
      backend.
    - Servers that take too long to respond are also removed
      from the backend. The default timeout value is 2s.

    [0] https://tracker.ceph.com/issues/11682
    [1] https://www.haproxy.com/documentation/hapee/2-0r1/onepage/#4.2-option%20httpchk

    Closes-Bug: 1946280
    Change-Id: I82634255ca3423fec3fc15c1e714dcb31db5da7a