PulseAudio + qemu-kvm VNC gives no sound

[Lucio Seki <ls...@redhat.com>]

Hi there,

Could you folks please help me understand how PulseAudio + VNC should work?

I followed the Audio support (via PulseAudio) guide [0], and I'm able to
make Guacd connect to the PulseAudio server running on my laptop.
But I hear no sound coming from the remote machine.


What I've done so far:
===

I'm running everything on my laptop.
The "remote machine" is a RHEL 8.4 VM, running on top of qemu-kvm. I access
it through the qemu-kvm built-in VNC server.
The Guacamole and Guacd services are running as separate Podman containers.
From my browser, I can access my remote machine's graphical interface
through the Guacamole containers.

Now I want to hear the sound coming from the remote machine.
I added the following line to my local machine's `/etc/pulse/default.pa`:

load-module module-native-protocol-tcp auth-anonymous=1

... and added the following parameters to the request to Guacamole:

'guac.enable-audio': "true",
'guac.audio-servername': "192.168.122.10",

`192.168.122.10` is my laptop's virbr0 interface IP address.
When I connect to the remote machine, Guacd logs show the following lines:

guacd[105]: INFO: Connecting to PulseAudio...
guacd[105]: INFO: Authorizing PulseAudio connection...
guacd[105]: INFO: Sending client name...
guacd[105]: INFO: PulseAudio now ready
guacd[105]: INFO: Will use default sink:
"alsa_output.usb-Dell_DELL_Slim_Soundbar_SB521A_SB521A-00.analog-stereo"
guacd[105]: INFO: Starting streaming from "DELL Slim Soundbar SB521A Analog
Stereo"
guacd[105]: INFO: PulseAudio stream being created...
guacd[105]: INFO: PulseAudio stream now ready

`DELL Slim Soundbar ...` is the speaker attached to my laptop.


What I was expecting:
===

I thought I could hear the sounds coming from the remote machine, by simply
running `speaker-test` there.


What I'm getting:
===

I hear no sound at all.
My speaker is working fine, as I can hear sounds from my local machine.

What am I doing wrong?

[0]
https://guacamole.apache.org/doc/gug/configuring-guacamole.html#audio-support-via-pulseaudio

-- 

Lucio Seki

He / Him / His

Senior Systems Administrator, RH Training - Learning Platforms

Red Hat <https://www.redhat.com/>

lucio@redhat.com
<https://www.redhat.com/>