[router advertiser] Only start radvd process if device role is 'ToRRouter' (#1569)

dockers/docker-router-advertiser/docker-router-advertiser.supervisord.conf

@@ -8,6 +8,7 @@ command=/usr/bin/start.sh
 priority=1
 autostart=true
 autorestart=false
+startsecs=0
 stdout_logfile=syslog
 stderr_logfile=syslog
 

dockers/docker-router-advertiser/start.sh

@@ -1,11 +1,18 @@
 #!/usr/bin/env bash
 
-# Generate /etc/radvd.conf config file
-sonic-cfggen -d -t /usr/share/sonic/templates/radvd.conf.j2 > /etc/radvd.conf
-
 rm -f /var/run/rsyslogd.pid
 
 supervisorctl start rsyslogd
 
+# Router advertiser should only run on ToR (T0) devices
+DEVICE_ROLE=$(sonic-cfggen -d -v "DEVICE_METADATA.localhost.type")
+if [ "$DEVICE_ROLE" != "ToRRouter" ]; then
+    echo "Device role is not ToRRouter. Not starting router advertiser process."
+    exit 0
+fi
+
+# Generate /etc/radvd.conf config file
+sonic-cfggen -d -t /usr/share/sonic/templates/radvd.conf.j2 > /etc/radvd.conf
+
 # Start the router advertiser
 supervisorctl start radvd