[mythtvnz] New install - mythbackend password not accepted

[Paul]

On 7/04/21 10:10 pm, Stephen Worthington wrote:
> On Wed, 7 Apr 2021 15:31:30 +1200, you wrote:
>
>> I installed your helper scripts and it is looking good but with a couple
>> of idiosyncrasies.
>>
>> I was running htop on a second workspace to monitor the stopping and
>> starting of the backend.
>>
>> When I start myth backend setup  a small dialogue opens stating that
>> myth backend needs to be closed > selecting 'Yes' results in a mythtv
>> dialogue asking for a password - which won't accept the sudo password or
>> any password in the known universe. NB there are two users: the Xubuntu
>> user called myth and mythtv , I don't know if that is enlightening.
> There should not be a password request here.  The question about
> shutting down mythbackend is new in v31 I think, and will always be
> there, but after that there should not be any further dialogs - the
> helper script should be run and mythbackend should shut down.
>
> However, shutting down mythbackend has a complication.  When MythTV
> programs such as mythbackend or mythfrontend are requested to shut
> down externally, there is a bug in the MythTV codebase that happens.
> The request to shut down is a "kill -15" aka "kill -SIGTERM".  When
> MythTV code receives one of these signals, it mostly shuts down except
> for one final thread, which keeps on running.  Sending a second "kill
> -15" shortly after the first one will shut down this final thread. The
> systemd .service file for mythbackend (mythtv-backend.service) does
> not know about this problem as installed from the packages.  It only
> sends one "kill -15" and then waits for mythbackend to stop - and
> keeps on waiting and waiting and when it finally times out (90?
> seconds later), it does a kill -9 on mythbackend which then kills off
> the last thread.  The kill -9 happening does no damage as mythbackend
> is no longer doing anything, just waiting in that final thread.  But
> that long timeout will be affecting you as mythbackend will still be
> running when mythtv-setup starts.  So I think you need to install my
> fix for this problem:
>
> https://lists.archive.carbon60.com/mythtv/users/627999
> (search that page for "mythbackendstop.sh")
>
> Installing this fix will not fix the problem of a password dialog
> popping up - that should not be happening with my helper scripts in
> place.
>
>> The password dialogue is despatched into the land of wind and ghosts
>> with a simple esc keystroke or clicking 'X' or "Cancel"
>>
>> A terminal window shows myth backend setup starting.
>>
>> Myth backend setup opens and states the backend is running and htop
>> confirms this > selecting 'stop backend' closes the message box and
>> ,after 10 seconds,myth backend setup is ready for use.
>>
>> Exiting myth backend setup results in the GUI closing , A terminal
>> window shows myth backend  starting, a mythtv dialogue asking for a
>> password appears which is  closed with an "esc" . A dialogue opens
>> asking if I want to run mythfilldatabase.
> I am afraid I just do not understand where that password dialog is
> coming from, unless the sudoers setup is not correct.  Check that
> setup by doing these commands:
>
> ll /etc/sudoers.d/mythtv-systemctl-helper
> cat /etc/sudoers.d/mythtv-systemctl-helper
>
> This is what I get:
>
> root at mypvr:/usr/local/bin# ll /etc/sudoers.d/mythtv-systemctl-helper
> -r--r----- 1 root root 70 Jun  7  2020
> /etc/sudoers.d/mythtv-systemctl-helper
> root at mypvr:/usr/local/bin# cat /etc/sudoers.d/mythtv-systemctl-helper
> mythtv,%mythtv ALL=NOPASSWD:/usr/local/bin/mythtv-systemctl-helper.sh
>
> If the sudoers setup was wrong, dismissing the password dialog should
> result in the helper script never being run, so mythbackend would just
> keep on running.
>
>> htop confirms myth backend is running.
>>
>> When the helper script commands had the error (typo) the 10 second delay
>> was where the Myth backend setup would hang indefinitely.
>>
>> Except for the irrelevant password requests it seems to be behaving
>> pretty much the same as my existing Mythbuntu 16.04 installation.
>>
>>
>>>    mysql> select * from settings where data like '%helper%' order by hostname;
>>> +---------------------+-----------------------------------------------------------+-------------+
>>> | value               | data                                                      | hostname    |
>>> +---------------------+-----------------------------------------------------------+-------------+
>>> | ServerHaltCommand   | sudo /home/mythtv/bin/mythtv-systemctl-helper.sh halt     | NULL        |
>>> | BackendStopCommand  | sudo /home/mythtv/bin/mythtv-systemctl-helper.sh stop     | NULL        |
>>> | BackendStartCommand | sudo /home/mythtv/bin/mythtv-systemctl-helper.sh start    | NULL        |
>>> | HaltCommand         | sudo /home/mythtv/bin/mythtv-systemctl-helper.sh poweroff | myth-system |
>>> | RebootCommand       | sudo /home/mythtv/bin/mythtv-systemctl-helper.sh reboot   | myth-system |
>>> +---------------------+-----------------------------------------------------------+-------------+
>>> 5 rows in set (0.00 sec)
> That all looks right.
>
>> Set up will continue over following days.
>>
>> Thanks
>>
>> Paul
> BTW The same shutdown bug happens in mythfrontend, so I have a script
> that sends it two "kill -15" that I use to shut it down when it
> freezes on a bug or otherwise.  Running "killm" will kill only
> "mythfrontend.real" and the mythfrontend script will then restart it.
> Running "killm x" (any parameter value) will kill the "mythfrontend"
> script and then kill "mythfrontend.real", so it will not restart.
>
> To install killm on Ubuntu run this:
>
> sudo su
> cd /usr/local/bin
> wget http://www.jsw.gen.nz/mythtv/killm
> chown root:root killm
> chmod u=rwx,og=rx killm
> exit
>
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I'll check the sudoers.d helper and make the other changes regarding the 
shutdown bug .

One thing I wondered about regarding the helper script was ,in your 
installation procedure ,for the helper script in /mythtv/bin you issue: 
chmod ug=rx,o= mythtv-systemctl-helper.sh  command and for the one in 
/etc/sudoers.d you use: chmod ug=r,o= mythtv-systemctl-helper  without x 
to make executable. Was this intentional? or a typo?

I'll be busy for the following 2 days and be  making the changes on 
Saturday.

-Paul