[vs]: dynamically create front panel ports in vs docker (#4499)

currently, vs docker always create 32 front panel ports.

when vs docker starts, it first detects the peer links
in the namespace and then setup equal number of front panel
interfaces as the peer links.

Signed-off-by: Guohan Lu <lguohan@gmail.com>

files/build_templates/buffers_config.j2

@@ -7,7 +7,7 @@ def
 {%- endmacro -%}
 
 {# Determine device topology and filename postfix #}
-{%- if DEVICE_METADATA is defined %}
+{%- if DEVICE_METADATA is defined and DEVICE_METADATA['localhost']['type'] is defined %}
 {%-     set switch_role = DEVICE_METADATA['localhost']['type'] %}
 {%-     if switch_role.lower() == 'torrouter' %}
 {%-         set filename_postfix = 't0' %}

platform/vs/README.vsdocker.md

@@ -1,42 +1,12 @@
 HOWTO Use Virtual Switch (Docker)
 
 
-1. Create a docker with 32 front panel port
+1. Create a docker with two front panel ports
 
 ```
 $ docker run -id --name sw debian bash
-$ sudo ./create_vnet.sh sw
+$ sudo ./create_vnet.sh -n 2 sw
 $ ip netns list
-sw-srv31 (id: 37)
-sw-srv30 (id: 35)
-sw-srv29 (id: 34)
-sw-srv28 (id: 33)
-sw-srv27 (id: 32)
-sw-srv26 (id: 31)
-sw-srv25 (id: 30)
-sw-srv24 (id: 29)
-sw-srv23 (id: 28)
-sw-srv22 (id: 27)
-sw-srv21 (id: 26)
-sw-srv20 (id: 25)
-sw-srv19 (id: 24)
-sw-srv18 (id: 23)
-sw-srv17 (id: 22)
-sw-srv16 (id: 21)
-sw-srv15 (id: 20)
-sw-srv14 (id: 19)
-sw-srv13 (id: 18)
-sw-srv12 (id: 17)
-sw-srv11 (id: 16)
-sw-srv10 (id: 15)
-sw-srv9 (id: 14)
-sw-srv8 (id: 13)
-sw-srv7 (id: 12)
-sw-srv6 (id: 11)
-sw-srv5 (id: 10)
-sw-srv4 (id: 9)
-sw-srv3 (id: 8)
-sw-srv2 (id: 7)
 sw-srv1 (id: 6)
 sw-srv0 (id: 5)
 ```
@@ -51,8 +21,10 @@ $ docker run --privileged --network container:sw --name vs -d docker-sonic-vs
 
 ```
 $ docker exec -it vs bash
-root@2e9b5c2dc2a2:/# ifconfig Ethernet0 10.0.0.0/31 up
-root@2e9b5c2dc2a2:/# ifconfig Ethernet4 10.0.0.2/31 up
+root@2e9b5c2dc2a2:/# config interface ip add Ethernet0 10.0.0.0/31
+root@2e9b5c2dc2a2:/# config interface ip add Ethernet4 10.0.0.2/31
+root@2e9b5c2dc2a2:/# config interface startup Ethernet0
+root@2e9b5c2dc2a2:/# config interface startup Ethernet4
 ```
 
 4. Setup IP in the server network namespace

platform/vs/create_vnet.sh

@@ -1,4 +1,24 @@
-#!/bin/bash
+#!/bin/bash -e
+
+usage() {
+	echo "Usage: $0 [-n <int>] swname" 1>&2
+    exit 1
+}
+
+SERVERS=2
+
+while getopts ":n:" opt; do
+    case $opt in
+        n)
+            SERVERS=$((OPTARG))
+            ;;
+        *)
+            usage
+			;;
+    esac
+done
+
+shift $((OPTIND-1))
 
 SWNAME=$1
 
@@ -6,9 +26,8 @@ pid=$(docker inspect --format '{{.State.Pid}}' $SWNAME)
 
 echo Seting up servers
 
-SERVERS=31
 
-for srv in `seq 0 $SERVERS`; do
+for srv in `seq 0 $((SERVERS-1))`; do
 
     SRV="$SWNAME-srv$srv"
 
@@ -24,9 +43,10 @@ for srv in `seq 0 $SERVERS`; do
 
     IF="eth$((srv+1))"
 
-    ip link add ${SRV}eth0 type veth peer name $IF
+    ip link add ${SRV}eth0 type veth peer name $SWNAME-$IF
     ip link set ${SRV}eth0 netns $SRV
-    ip link set $IF netns ${pid}
+    ip link set $SWNAME-$IF netns ${pid}
+    nsenter -t $pid -n ip link set dev $SWNAME-$IF name $IF
 
     echo "Bring ${SRV}eth0 up"
     $NSS ip link set dev ${SRV}eth0 name eth0

platform/vs/docker-sonic-vs/start.sh

@@ -7,6 +7,23 @@ HWSKU=Force10-S6000
 
 ln -sf /usr/share/sonic/device/$PLATFORM/$HWSKU /usr/share/sonic/hwsku
 
+pushd /usr/share/sonic/hwsku
+
+# filter available front panel ports in lanemap.ini
+[ -f lanemap.ini.orig ] || cp lanemap.ini lanemap.ini.orig
+for p in $(ip link show | grep -oE "eth[0-9]+" | grep -v eth0); do
+    grep ^$p: lanemap.ini.orig
+done > lanemap.ini
+
+# filter available sonic front panel ports in port_config.ini
+[ -f port_config.ini.orig ] || cp port_config.ini port_config.ini.orig
+grep ^# port_config.ini.orig > port_config.ini
+for lanes in $(awk -F ':' '{print $2}' lanemap.ini); do
+    grep -E "\s$lanes\s" port_config.ini.orig
+done >> port_config.ini
+
+popd
+
 [ -d /etc/sonic ] || mkdir -p /etc/sonic
 
 SYSTEM_MAC_ADDRESS=$(ip link show eth0 | grep ether | awk '{print $2}')
@@ -17,7 +34,7 @@ if [ -f /etc/sonic/config_db.json ]; then
     mv /tmp/config_db.json /etc/sonic/config_db.json
 else
     # generate and merge buffers configuration into config file
-    sonic-cfggen -t /usr/share/sonic/hwsku/buffers.json.j2 > /tmp/buffers.json
+    sonic-cfggen -k $HWSKU -p /usr/share/sonic/hwsku/port_config.ini -t /usr/share/sonic/hwsku/buffers.json.j2 > /tmp/buffers.json
     sonic-cfggen -j /etc/sonic/init_cfg.json -t /usr/share/sonic/hwsku/qos.json.j2 > /tmp/qos.json
     sonic-cfggen -p /usr/share/sonic/hwsku/port_config.ini -k $HWSKU --print-data > /tmp/ports.json
     sonic-cfggen -j /etc/sonic/init_cfg.json -j /tmp/buffers.json -j /tmp/qos.json -j /tmp/ports.json --print-data > /etc/sonic/config_db.json