local-looper: Utilise service watchdog.

cmd/local-looper/README.md

@@ -1,6 +1,6 @@
 # DESCRIPTION
 	local looper is a process which will continually loop a pcm audio file
-	(like looper). The intended hardware for this system is a raspberry pi
+	(like looper: "av/cmd/looper/"). The intended hardware for this system is a raspberry pi
 	zero W, with a USB sound card (AUDIODEV=hw:(1,0)).
 
 # AUTHORS

cmd/local-looper/looper.service

@@ -7,5 +7,9 @@ User=pi
 WorkingDirectory=/home/pi/
 ExecStart=/bin/bash /home/pi/looper.sh
 
+Type=notify
+WatchdogSec=70s
+Restart=on-failure
+
 [Install]
 WantedBy=multi-user.target

cmd/local-looper/looper.sh

@@ -1,6 +1,9 @@
 #!/bin/bash
 
+systemd-notify --ready
+
 export AUDIODEV=hw:1,0
 while true; do
   play -q -V0 -t raw -r 44.1k -e signed -b 16 -c 1 /home/pi/shrimp.pcm
+  systemd-notify --status="service is running" WATCHDOG=1
 done