Actually, using "copytruncate" option in the logrotate config file
might be a better solution.

Reminder for possible heads up in release notes:

When the user performes update of luci to version in "Fixed in version"
field or higher, hence when updating manually can observe

> warning: /etc/logrotate.d/luci created as /etc/logrotate.d/luci.rpmnew

if some changes were made to /etc/logrotate.d/luci, she is suggested
to drop

>    postrotate
>        /sbin/service luci condrestart 2>/dev/null >/dev/null || :
>    endscript

from that file (or just "cp /etc/logrotate.d/luci{.rpmnew,}")
to avoid now spurious/unneeded restarts of luci when rotating the logs
kicks in.

(This because the file is marked %config(noreplace).)

I missed the "corner case" of initial luci setup:

# paster setup-app /var/lib/luci/etc/luci.ini --no-default-sysconfig
> Traceback (most recent call last):
>   File "/usr/bin/paster", line 9, in <module>
>     load_entry_point('PasteScript==1.7.3', 'console_scripts', 'paster')()
>   File "/usr/lib/python2.6/site-packages/paste/script/command.py", line 84, in run
>     invoke(command, command_name, options, args[1:])
>   File "/usr/lib/python2.6/site-packages/paste/script/command.py", line 123, in invoke
>     exit_code = runner.run(args)
>   File "/usr/lib/python2.6/site-packages/paste/script/appinstall.py", line 68, in run
>     return super(AbstractInstallCommand, self).run(new_args)
>   File "/usr/lib/python2.6/site-packages/paste/script/command.py", line 218, in run
>     result = self.command()
>   File "/usr/lib/python2.6/site-packages/paste/script/appinstall.py", line 446, in command
>     self.logging_file_config(config_file)
>   File "/usr/lib/python2.6/site-packages/paste/script/command.py", line 757, in logging_file_config
>     fileConfig(config_file)
>   File "/usr/lib64/python2.6/logging/config.py", line 84, in fileConfig
>     handlers = _install_handlers(cp, formatters)
>   File "/usr/lib64/python2.6/logging/config.py", line 161, in _install_handlers
>     args = eval(args, vars(logging))
>   File "<string>", line 1, in <module>
> AttributeError: 'file' object has no attribute 'filename'

There was yet another issue found with the new changes:

The problem occurs  when you install luci anew and set LOG_FILE to
a nondefault value, the proceed with "service luci start".
Some early setup tasks (not triggered upon subsequently start of luci)
have to -- by design -- resort to using default log file, but then
it's not precreated with correct owner (root instead) so it subsequently
fails on inability to write to that file.

This is now fixed and both custom + default log files are initially
pre-created with desired owner so this failure can no longer happen.

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://rhn.redhat.com/errata/RHBA-2017-0766.html