[mythtv-users] Unable to connect to the master backend at 192.168.1.100:6543 (16.04 & 0.28)

[Bill Meek]

On 04/18/2016 09:12 AM, Fred Hamilton wrote:
> Roger nailed it!  I've been running mythbackend with my normal privileges
> and it would say "The backend is currently running", I would select "Stop
> Backend and Continue", and then when exiting I'd choose to restart
> backend.  So I thought each time I ran mythtv-setup I was stopping and
> restarting mythbackend.  But of course it was running the whole time - that
> only works with escalated privileges.  So I stopped and restarted
> mythbackend and now mythweb is working!  mythtv-status is still not working
> 100%, supporting Roger's theory that it's a different pre-existing bug.
>
> Fred, if Roger's test works, there's a solution available for the
>> mythtv-backend
>> .service to prevent the problem. Please confirm if/that the backend can be
>> restarted
>> after boot and works OK.
>
>
> Confirmed - what's the solution?

This issue was worked off-line and Fred confirmed that his system
didn't have an existing ExecStartPre line in the .service file, so
one solution is:

Stop the backend:

     sudo systemctl stop  mythtv-backend

Add a line to the mythtv-backend.service.

This is what I use, but last I heard, 'Ubuntu server' didn't have nm-online, so their
backends wouldn't start and it was removed from the Mythbuntu .service file:

     ExecStartPre=/usr/bin/nm-online --quiet --timeout=5

There's more detail in man nm-online and for systemd, another solution
that I haven't tried:

     https://www.freedesktop.org/wiki/Software/systemd/NetworkTarget/

The way to get the mythtv-backend.service changed locally is to put the changed
copy in /etc/systemd/system/mythtv-backend.service which will override the one
in /lib/systemd/system. That way if a new version is released, your's won't be
changed. Of course if a *fix* is released by Mythbuntu, it will likely be unknown
to you unless you keep checking the version in /lib...

When you're done adding it, do:

     sudo systemctl daemon-reload

Then start the backend again:

     sudo systemctl start  mythtv-backend

You should also check your mythtv-setup's backend start and stop commands. Test
them from the command line. The 'old' System V format: service start/stop mythtv-backend
doesn't work on my system for example. The same is likely true for Upstart commands like
sudo start mythtv.backend.

I'll leave the above to Mythbuntu users. If an upgrade to 16.04 is done,
do the backend start and stop commands get changed automatically? Does
there need to be an accompanying change to /etc/sudoers.d/mythtv to allow
the new systemd commands to be run by mythtv and the login user?

-- 
Bill