Comment 2 for bug 1709970

Reviewed: https://review.openstack.org/492651
Committed: https://git.openstack.org/cgit/openstack-dev/devstack/commit/?id=a3488d5f0067b570974c14572c58bbf8cedf7ed2
Submitter: Zuul
Branch: master

commit a3488d5f0067b570974c14572c58bbf8cedf7ed2
Author: Matthew Treinish <email address hidden>
Date: Thu Aug 10 14:55:15 2017 -0400

    Remove proxy-sendcl from mod_proxy_uwsgi apache path

    Calling setenv appears to be globally scoped which is breaking the
    glance path which relies on chunked uploads. The glance path is
    separated by using mod_proxy instead of mod_proxy_uwsgi because
    mod_proxy_uwsgi doesn't support chunked encoding.[1] The proxy-sendcl [2]
    was set on the mod_proxy_uwsgi path just in case someone tried to send a
    chunked request to the api server we would be able to handle it. It
    tells apache to locally cache the chunked request and send the
    content-length as a normal upload to the upstream server. However, if we
    can only set it globally across then small potential benefit is not worth
    having all glance uploads cached by apache. This commit just removes
    setting the flag. In the future if we can have devstack isolate this
    flag it might be worth adding back to the mod_proxy_uwsgi path, but for
    right now it's not worth the tradeoff.

    [1] https://github.com/unbit/uwsgi/issues/1540
    [2] https://httpd.apache.org/docs/2.4/mod/mod_proxy.html#request-bodies

    Depends-On: Idf6b4b891ba31cccbeb53d373b40fce5380cea64
    Change-Id: Iab2e2848877fa1497008d18c05b0154892941589
    Closes-Bug: #1709970