adding dbus and avahi to enable shairport-sync to work correctly

Dockerfile

@@ -13,6 +13,7 @@ RUN set -ex \
   && echo "**** install runtime packages ****" \
   && apk add --no-cache -U --upgrade \
     alsa-utils \
+    dbus \
     librespot@testing \
     shairport-sync@testing \
     snapcast \

root/etc/s6-overlay/s6-rc.d/svc-avahi/data/check

@@ -0,0 +1,9 @@
+#!/bin/sh
+state="$(dbus-send --system --dest=org.freedesktop.Avahi --print-reply / org.freedesktop.Avahi.Server.GetState | grep int32 | awk '{printf $2}')"
+
+# Avahi will return 'state=2' when 'Server startup complete'
+if [ "$state" = 2 ]; then
+    exit 0
+else
+    exit 1
+fi

root/etc/s6-overlay/s6-rc.d/svc-avahi/finish

@@ -0,0 +1,2 @@
+#!/command/execlineb -S0
+/run/s6/basedir/bin/halt

root/etc/s6-overlay/s6-rc.d/svc-avahi/notification-fd

@@ -0,0 +1 @@
+3

root/etc/s6-overlay/s6-rc.d/svc-avahi/run

@@ -0,0 +1,4 @@
+#!/usr/bin/with-contenv bash
+
+echo "Starting avahi"
+exec s6-notifyoncheck avahi-daemon --no-chroot

root/etc/s6-overlay/s6-rc.d/svc-avahi/type

@@ -0,0 +1 @@
+longrun

root/etc/s6-overlay/s6-rc.d/svc-dbus/data/check

@@ -0,0 +1,2 @@
+#!/bin/sh
+exec dbus-send --system / org.freedesktop.DBus.Peer.Ping > /dev/null 2> /dev/null

root/etc/s6-overlay/s6-rc.d/svc-dbus/finish

@@ -0,0 +1,2 @@
+#!/command/execlineb -S0
+/run/s6/basedir/bin/halt

root/etc/s6-overlay/s6-rc.d/svc-dbus/notification-fd

@@ -0,0 +1 @@
+3

root/etc/s6-overlay/s6-rc.d/svc-dbus/run

@@ -0,0 +1,5 @@
+#!/usr/bin/with-contenv bash
+
+echo "Starting dbus"
+mkdir -p /var/run/dbus
+exec s6-notifyoncheck dbus-daemon --system --nofork --nopidfile

root/etc/s6-overlay/s6-rc.d/svc-dbus/type

@@ -0,0 +1 @@
+longrun