Add the ability to create a P2P tunnel from the CLI

[VladysavBondarGL]

What I did

Added the ability to create a P2P VxLAN tunnel from the CLI

How I did it

Extended the existing config vxlan add ... command with an optional dst_ip argument. The implementation logic was already existent.

How to verify it

root@sonic:~# config vxlan add vxlan0 1.1.1.1 2.2.2.2
root@sonic:~# config vlan add 100
root@sonic:~# config vxlan map add vxlan0 100 1000

root@sonic:~# ip -d link show dev vxlan0-100
53: vxlan0-100: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master Bridge state UNKNOWN mode DEFAULT group default qlen 1000
    link/ether 0c:52:4a:3a:00:00 brd ff:ff:ff:ff:ff:ff promiscuity 1 minmtu 68 maxmtu 65535 
    vxlan id 1000 remote 2.2.2.2 local 1.1.1.1 srcport 0 0 dstport 4789 nolearning ttl auto ageing 300 udpcsum noudp6zerocsumtx noudp6zerocsumrx 
    bridge_slave state forwarding priority 32 cost 100 hairpin off guard off root_block off fastleave off learning on flood on port_id 0x8002 port_no 0x2 designated_port 32770 designated_cost 0 designated_bridge 8000.c:52:4a:3a:0:0 designated_root 8000.c:52:4a:3a:0:0 hold_timer    0.00 message_age_timer    0.00 forward_delay_timer    0.00 topology_change_ack 0 config_pending 0 proxy_arp off proxy_arp_wifi off mcast_router 1 mcast_fast_leave off mcast_flood on mcast_to_unicast off neigh_suppress off group_fwd_mask 0 group_fwd_mask_str 0x0 vlan_tunnel off isolated off addrgenmode eui64 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 

root@sonic:~# jq '.VXLAN_TUNNEL' /etc/sonic/config_db.json 
{
  "vxlan0": {
    "dst_ip": "2.2.2.2",
    "src_ip": "1.1.1.1"
  }
}

Previous command output (if the output of a command-line utility has changed)

No output was modified

New command output (if the output of a command-line utility has changed)

Help message now shows additional optional argument:

root@sonic:~# config vxlan add -h
Usage: config vxlan add [OPTIONS] <vxlan_name> <src_ip> [dst_ip]

  Add VXLAN

Options:
  -h, -?, --help  Show this message and exit.

Error message for invalid dst_ip:

root@sonic:~# config vxlan add vxlan0 10.0.0.1 1.2.3.4.5
Usage: config vxlan add [OPTIONS] <vxlan_name> <src_ip> [dst_ip]
Try "config vxlan add -h" for help.

Error: 1.2.3.4.5 invalid dst ip address