platform.conf has two different system_mode entries after ansible install

[Allain Legacy]

Brief Description
-----------------
The /etc/platform/platform.conf file has two different system_mode entries after running Ansible remotely to configure a target host. One entries reports "simplex" while the other reports "duplex".

controller-0:~$ cat /etc/platform/platform.conf
nodetype=controller
subfunction=controller
system_type=Standard
security_profile=standard
management_interface=lo
http_port=8080
INSTALL_UUID=de86e7ca-4649-41d2-be34-0c1061802439
UUID=29709c5e-1859-4915-9d1f-3ac803dace20
sdn_enabled=no
region_config=no
system_mode=duplex
sw_version=19.01
security_feature="nopti nospectre_v2"
vswitch_type=none
system_mode=simplex
controller-0:~$

Severity
--------
Unknown system impact. The order of file parsing likely impact which value would be used. The impact may be different depending on which subsystem is reading that value.

Steps to Reproduce
------------------
Remotely install a target using Ansible.

Expected Behavior
------------------
Only 1 "system_mode" entry should exist.

Actual Behavior
----------------
Multiple "system_mode" entries exist.

Reproducibility
---------------
100%

System Configuration
--------------------
Standard

Branch/Pull Time/Commit
-----------------------
Private load rebased to May 10th.

Last Pass
---------
Unknown

Timestamp/Logs
--------------
See data above.

Test Activity
-------------
Developer Testing

[Ghada Khalil (gkhalil)]

Marking as release gating until further investigation. The concern here is that the two values are not the same

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/661392

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/661815

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/661815
Committed: https://git.openstack.org/cgit/starlingx/config/commit/?id=4868debd60f3d27edc477d5825c69ca5a9dc1818
Submitter: Zuul
Branch: master

commit 4868debd60f3d27edc477d5825c69ca5a9dc1818
Author: Tee Ngo <email address hidden>
Date: Tue May 28 11:59:44 2019 -0400

    Remove extra system_mode in platform.conf

    This commit removes the obsolete code that used to serve as a
    workaround for a maintenance issue which has long been resolved.

    The existence of this obsolete code has a side effect as
    described in LP https://bugs.launchpad.net/starlingx/+bug/1829059
    which is observed during bootstrap phase and in duplex systems
    only.

    The impact of this side effect has not been realized as the system
    mode is persisted correctly in sysinv database and both simplex
    and duplex systems have been brought up successfully with Ansible
    bootstrap. However, this could cause some confusion to the users
    who view the platform.conf file on controller-0 or potential
    incorrect value to custom utility tools/processes that obtain this
    parameter from platform.conf before the initial controller-0 unlock.

    Test:
      Verify that /etc/platform/platform.conf on controller-0 in a
      standard system contains only one entry of system_mode
      (system_mode=duplex) after playbook run and and that the
      system can be brought up successfully.

    Closes-Bug: 1829059
    Change-Id: I7706e122ec28cf38d63c3bbcb00825125a32c76d
    Signed-off-by: Tee Ngo <email address hidden>