Comment 4 for bug 1647421

Reviewed: https://review.opendev.org/693645
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=139b496ef957364caee6861fd16676cdfb76a38b
Submitter: Zuul
Branch: master

commit 139b496ef957364caee6861fd16676cdfb76a38b
Author: Reedip <email address hidden>
Date: Mon Nov 11 10:54:42 2019 +0900

    Dont schedule Network, respecting network_auto_schedule config

    Currently, if dhcp mapping from a network is removed, it is reassigned
    to the network. This is because of the Network Scheduler's schedule
    function, which considers balancing the networks with the agents, whether
    enable_dhcp is set on its subnets or not. It does not take into account
    the network_auto_schedule config option. This is particularly disturbing
    when considering backends which have their provide their own DHCP.

    With this patch, if network_auto_schedule is set to False, networks wont
    be automatically scheduled to DHCP Agents. If DHCP is to be mapped to a
    network, it can be mapped using the CLI itself.

    While it may seem that this change is breaking what is already working,
    but as mentioned earlier, if there are network backends which provide DHCP
    support themselves, they wont need the automatic mapping, which the term
    "network_auto_schedule" actually stands for.

    Closes-Bug: #1647421
    Change-Id: If1a6a2a174d0f737415efa2abce518722316a77b