Can we play sound in systemd service + no login?

[knorth55]

Yes, there is a solution.

We cannot play sound in systemd service + no login normally.
this is because pulseaudio starts when user log in.
when you login to some user, the pulseaudio user service starts and /run/user/{u-id}/pulse will be created.
but without login, /run/user/{u-id}/pulse will not created, so sound_play cannot play the sound.
i found a solution and there are 2 things to do in the solution.

1. run pulseaudio in system wide mode (not user mode)
2. set XDG_RUNTIME_DIR properly in your service

run pulseaudio in system wide mode (not user mode)

disable user pulseaudio service

sudo systemctl --global disable pulseaudio.service pulseaudio.socket

enable system pulseaudio service

put the following pulseaudio.service file in /etc/systemd/system

[Unit]
Description=PulseAudio system server

[Service]
Type=notify
ExecStart=/usr/bin/pulseaudio --daemonize=no --system --realtime --disallow-exit --disallow-module-loading --log-target=journal
Restart=on-failure

[Install]
WantedBy=multi-user.target

change /etc/pulse/default.pa and /etc/pulse/system.pa

set this in default.pa and system.pa

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

change /etc/pulse/client.conf

set this in /etc/pulse/client.conf

default-server = /var/run/pulse/native
autospawn = no

change /etc/pulse/daemon.conf

set this in /etc/pulse/daemon.conf

exit-idle-time = -1

add all users in audio, bluetooth pulse-access groups

sudo adduser {user name} audio
sudo adduser {user name} bluetooth
sudo adduser {user name} pulse-access

set XDG_RUNTIME_DIR properly in your service

set XDC_RUNTIME_DIR in your service file

[Service]
Environment=XDG_RUNTIME_DIR=/var/run

Reboot

Then you can now play sound from systemd

ref. https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/SystemWide/