[LAD] Simple Pipewire test request

[Fernando Lopez-Lezcano]

On 7/8/21 11:29 AM, John Murphy wrote:
> On Thu, 8 Jul 2021 08:56:56 -0700 Fernando Lopez-Lezcano wrote:
>> On 7/7/21 11:24 AM, John Murphy wrote:
>>> On Wed, 7 Jul 2021 19:01:25 +0100 Keith Edmunds wrote:
>>>> Try:
>>>>
>>>> /usr/bin/pw-record /home/john/crontest.wav > /tmp/cronjob.txt 2>&1
>>>>
>>>> ...and have a look in /tmp/cronjob.txt after it's run
>>>
>>> /tmp/cronjob.txt says error: pw_context_connect() failed: Host is down
>>>
>>> I've no idea what that means, or why that should be so.
>>
>> https://docs.pipewire.org/group__pw__core.html
>>
>> ----
>> Connect to a PipeWire instance.
>>
>> Returns
>>       a The Core Global Object on success or NULL with errno set on
>> error. The core will have an id of PW_ID_CORE (0)
>> ----
>>
>> So it would seem that the pipewire client cannot connect to the server
>> (or something like that). Could be ownership, permissions, even selinux
>> if it is running.
> 
> Thanks for the thoughts. There are some selinux libs installed,
> but not much else. I added a job to /etc/crontab like:
> 
> 04 19 * * * root /usr/bin/pw-record /home/john/crontest.wav > /tmp/cronjob.txt 2>&1
> and see the same error in the text file.

Maybe running as root is actually not enough :-(

I don't know how to fix this but it is likely that this does not 
establish a "session" (or "seat") and then dbus is not running and then 
nothing that depends on it can work. Maybe running the cron job as a 
normal user? I don't know how you can convince the system that you 
really are allowed to do all this...

< and if selinux is involved, maybe you can look at what is in the logs? 
/var/log/secure, /var/log/messages, and hunt for denials or permission 
problems? >

-- Fernando


>> It could also be that running things from cron does not establish a
>> "session" and then you do not have access permission to audio devices
>> and such (and dbus, as suggested elsewhere in the thread).
> 
> It's a long time since I've used root for anything, but I think it
> would still have the required permissions to do anything. I begin to
> wonder if this is by design, but I still don't know if it works for
> anyone else.
>