Add Resource NSX-T Route Advertisement

[mikeletux]

This PR relies on govcd PR vmware/go-vcloud-director#478

Description

This PR brings the possibility of adding route advertisement to an NSX-T Edge Gateway.

Detailed description

This new resource implements a new resource for NSX-T Edge Gateway, that allows to publish networks to the NSX-T Tier-0 Gateway. Please bear in mind that for this resource to work, the NSX-T Edge Gateway option "Use dedicate Tier-0 Gateway" must be active, otherwise this resource will fail on its creation.

An example HCL file where this resource is used could be:

data "vcd_org_vdc" "my_vdc" {
  org = "my-org"
  name = "my-vdc"
}

data "vcd_nsxt_edgegateway" "my_edge_gateway" {
  owner_id = data.vcd_org_vdc.my_vdc.id
  name     = "my-nsxt-edge-gateway"
}

resource "vcd_nsxt_route_advertisement" "my_route_advertisement" {
  edge_gateway_id = data.vcd_nsxt_edgegateway.my_edge_gateway.id
  enabled = true
  subnets = ["192.168.1.0/24", "192.168.2.0/24"]
}

As seen in the HCL code snippet, route advertisement will be enabled on NSX-T Edge Gateway and a couple of subnets will be advertised: 192.168.1.0/24 and 192.168.2.0/24.

[adambarreiro]

Nice work, thanks!

[vbauzys]

Almost there :)

[Didainius]

Thanks for all the fixes