Pulseaudio 作为系统范围的 systemd 服务

Question

我想在无外设的 CentOS 7 服务器上运行 Pulseaudio 系统。如果我 startx 但在文本模式（运行级别 3 等效）脉冲音频客户端失败，Pulseaudio 效果很好。

所以我创建了一个 systemd 服务文件：

[Unit]
Description=PulseAudio Daemon

[Install]
WantedBy=multi-user.target

[Service]
Type=simple
PrivateTmp=true
ExecStart=/usr/bin/pulseaudio --system --realtime --disallow-exit --no-cpu-limit 

它开始了，但我在 journalctl 中看到以下内容：

Jan 19 13:31:47 lserver.mydomain pulseaudio[2523]: W: [pulseaudio] main.c: Running in system mode, but --disallow-module-loading not set!
Jan 19 13:31:47 lserver.mydomain pulseaudio[2523]: N: [pulseaudio] main.c: Running in system mode, forcibly disabling SHM mode!
Jan 19 13:31:47 lserver.mydomain pulseaudio[2523]: N: [pulseaudio] main.c: Running in system mode, forcibly disabling exit idle time!
Jan 19 13:31:47 lserver.mydomain pulseaudio[2523]: W: [pulseaudio] main.c: OK, so you are running PA in system mode. Please note that you most likely shouldn't be doing that.
Jan 19 13:31:47 lserver.mydomain pulseaudio[2523]: W: [pulseaudio] main.c: If you do it nonetheless then it's your own fault if things don't work as expected.
Jan 19 13:31:47 lserver.mydomain pulseaudio[2523]: W: [pulseaudio] main.c: Please read http://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/WhatIsWrongWithSystemWide/ for an explanation why system mode is usually a bad idea.
Jan 19 13:31:48 lserver.mydomain pulseaudio[2523]: N: [pulseaudio] alsa-util.c: Disabling timer-based scheduling because running inside a VM.
Jan 19 13:31:48 lserver.mydomain pulseaudio[2523]: N: [pulseaudio] alsa-util.c: Disabling timer-based scheduling because running inside a VM.
Jan 19 13:31:48 lserver.mydomain pulseaudio[2523]: W: [pulseaudio] authkey.c: Failed to open cookie file '/var/run/pulse/.config/pulse/cookie': No such file or directory
Jan 19 13:31:48 lserver.mydomain pulseaudio[2523]: W: [pulseaudio] authkey.c: Failed to load authentication key '/var/run/pulse/.config/pulse/cookie': No such file or directory
Jan 19 13:31:48 lserver.mydomain pulseaudio[2523]: W: [pulseaudio] authkey.c: Failed to open cookie file '/var/run/pulse/.pulse-cookie': No such file or directory
Jan 19 13:31:48 lserver.mydomain pulseaudio[2523]: W: [pulseaudio] authkey.c: Failed to load authentication key '/var/run/pulse/.pulse-cookie': No such file or directory
Jan 19 13:31:48 lserver.mydomain systemd[1]: Got message type=signal sender=org.freedesktop.DBus destination=n/a object=/org/freedesktop/DBus interface=org.freedesktop.DBus member=NameOwnerChanged cookie=56 reply_cookie=0 error=n/a
Jan 19 13:31:48 lserver.mydomain systemd-logind[575]: Got message type=signal sender=org.freedesktop.DBus destination=n/a object=/org/freedesktop/DBus interface=org.freedesktop.DBus member=NameOwnerChanged cookie=56 reply_cookie=0 error=n/a
Jan 19 13:31:48 lserver.mydomain systemd-logind[575]: Got message type=signal sender=org.freedesktop.DBus destination=n/a object=/org/freedesktop/DBus interface=org.freedesktop.DBus member=NameOwnerChanged cookie=57 reply_cookie=0 error=n/a
Jan 19 13:31:48 lserver.mydomain systemd[1]: Got message type=signal sender=org.freedesktop.DBus destination=n/a object=/org/freedesktop/DBus interface=org.freedesktop.DBus member=NameOwnerChanged cookie=57 reply_cookie=0 error=n/a

并尝试访问音频失败：

speaker-test 1.1.1

Playback device is default
Stream parameters are 48000Hz, S16_LE, 1 channels
Using 16 octaves of pink noise
ALSA lib pulse.c:243:(pulse_connect) PulseAudio: Unable to connect: Access denied

Playback open error: -111,Connection refused

在扬声器测试后，日志显示：

Jan 19 14:06:39 lserver.ocg.ca pulseaudio[2795]: W: [pulseaudio] protocol-native.c: Denied access to client with invalid authentication data.

用户 root 被添加到“音频”组。并且speaker-test 正在以root 身份运行。有人可以建议如何解决这个问题吗？

Answer 1

经过一些实验，我发现修改 /etc/pulse/system.pa 以允许匿名：

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

音频现在可以正常播放。希望这有助于其他需要系统模式脉冲的人