Convert arp_update into a 'start-it-once' mode (#1864)

* Run arp_update just once, don't restart it. It will run continuosly with 5 min pauses

dockers/docker-orchagent/supervisord.conf

@@ -61,10 +61,10 @@ stdout_logfile=syslog
 stderr_logfile=syslog
 
 [program:arp_update]
-command=bash -c "/usr/bin/arp_update; sleep 300"
+command=/usr/bin/arp_update
 priority=8
 autostart=false
-autorestart=true
+autorestart=unexpected
 stdout_logfile=syslog
 stderr_logfile=syslog
 

files/scripts/arp_update

@@ -4,14 +4,17 @@
 # arp_update: Send gratuitous ARP requests to VLAN member neighbors to refresh
 # the neighbors state.
 
-VLAN=`sonic-cfggen -d -v 'VLAN.keys() | join(" ") if VLAN'`
-for vlan in $VLAN; do
-    # generate a list of arping commands:
-    #   arping -q -w 0 -c 1 -i <VLAN interface> <IP 1>;
-    #   arping -q -w 0 -c 1 -i <VLAN interface> <IP 2>;
-    #   ...
-    arpingcmd="sed -e 's/ / -i /' -e 's/^/arping -q -w 0 -c 1 /' -e 's/$/;/'"
-    ipcmd="ip -4 neigh show | grep $vlan | cut -d ' ' -f 1,3 | $arpingcmd"
+while /bin/true; do
+  VLAN=`sonic-cfggen -d -v 'VLAN.keys() | join(" ") if VLAN'`
+  for vlan in $VLAN; do
+      # generate a list of arping commands:
+      #   arping -q -w 0 -c 1 -i <VLAN interface> <IP 1>;
+      #   arping -q -w 0 -c 1 -i <VLAN interface> <IP 2>;
+      #   ...
+      arpingcmd="sed -e 's/ / -i /' -e 's/^/arping -q -w 0 -c 1 /' -e 's/$/;/'"
+      ipcmd="ip -4 neigh show | grep $vlan | cut -d ' ' -f 1,3 | $arpingcmd"
 
-    eval `eval $ipcmd`
+      eval `eval $ipcmd`
+  done
+  sleep 300
 done

platform/p4/docker-sonic-p4/supervisord.conf

@@ -133,9 +133,9 @@ stdout_logfile=syslog
 stderr_logfile=syslog
 
 [program:arp_update]
-command=bash -c "/usr/bin/arp_update; sleep 300"
+command=/usr/bin/arp_update
 priority=15
 autostart=false
-autorestart=true
+autorestart=unexpected
 stdout_logfile=syslog
 stderr_logfile=syslog

platform/vs/docker-sonic-vs/supervisord.conf

@@ -116,10 +116,10 @@ stdout_logfile=syslog
 stderr_logfile=syslog
 
 [program:arp_update]
-command=bash -c "/usr/bin/arp_update; sleep 300"
+command=/usr/bin/arp_update
 priority=15
 autostart=false
-autorestart=true
+autorestart=unexpected
 stdout_logfile=syslog
 stderr_logfile=syslog