API for GRE (including ERSPAN) about vpp-agent HOT 4 CLOSED

comment { create a xconnect between 2 user ports we want to span }
create packet-generator interface pg0
create packet-generator interface pg1
set int state pg0 up
set int state pg1 up
set int l2 xconnect pg0 pg1
set int l2 xconnect pg1 pg0

comment { GRE underlay }
create packet-generator interface pg2
set int ip address pg2 10.0.1.100/24
set ip arp pg2 10.0.1.22 6:5:4:3:2:1 static
set int state pg2 up

comment { GRE ERSPAN }
create gre tunnel dst 10.0.1.22 src 10.0.1.100 erspan 621
set int state gre0 up

comment { span a user interface (both directions) }
set int span pg0 destination gre0

comment { generate user traffic }
packet-generator new {
  name 0-to-1
  limit 1
  node ethernet-input
  size 64-64
  interface pg0
  data {
    0x8881: 4:4:4:4:4:4 -> 5:5:5:5:5:5
    incrementing 100
  }
}
packet-generator new {
  name 1-to-0
  limit 1
  node ethernet-input
  size 64-64
  interface pg1
  data {
    0x8881: 5:5:5:5:5:5 -> 4:4:4:4:4:4
    incrementing 100
  }
}
packet-generator enable