Vtysh support for multi asic (sonic-net#5479)

Signed-off-by: Arvindsrinivasan Lakshmi Narasimhan <[email protected]>

dockers/docker-fpm-frr/base_image_files/vtysh

@@ -1,4 +1,37 @@
 #!/bin/bash
+# read SONiC immutable variables
+[ -f /etc/sonic/sonic-environment ] && . /etc/sonic/sonic-environment
+
+function help()
+{
+    echo -e "Usage: $0 -n [0 to $(($NUM_ASIC-1))] [OPTION]... " 1>&2; exit 1;
+}
+
+DEV=""
+PLATFORM=${PLATFORM:-`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`}
+
+# Parse the device specific asic conf file, if it exists
+ASIC_CONF=/usr/share/sonic/device/$PLATFORM/asic.conf
+[ -f $ASIC_CONF ] && . $ASIC_CONF
+
+if [[ ($NUM_ASIC -gt 1) ]]; then
+    while getopts ":n:h:" opt; do
+        case "${opt}" in
+            h) help
+               ;;
+            n) DEV=${OPTARG}
+               [ $DEV -lt $NUM_ASIC -a  $DEV -ge 0 ] || help
+               ;;
+        esac
+    done
+
+    if [ -z "${DEV}" ]; then
+        help
+    fi
+
+    # Skip the arguments -n <inst> while passing to docker command
+    shift 2
+fi
 
 # Determine whether stdout is on a terminal
 if [ -t 1 ] ; then
@@ -7,10 +40,10 @@ if [ -t 1 ] ; then
   TTY=$(tty)
   function cleanup
   {
-    docker exec -i bgp pkill -HUP -f "vtysh $TTY"
+    docker exec -i bgp$DEV pkill -HUP -f "vtysh $TTY"
   }
   trap cleanup HUP
-  docker exec -ti bgp vtysh "$TTY" "$@"
+  docker exec -ti bgp$DEV vtysh "$TTY" "$@"
 else
-  docker exec -i bgp vtysh "$@"
+  docker exec -i bgp$DEV vtysh "$@"
 fi