Rsvp auto ero generation based on learned TE topology from IGP

[SouravSinhaRoy]

This is the proposal to add auto ero support to RSVP-TE in the OTG model based on the issue #298. The redocly view of the changes (https://redocly.github.io/redoc/?url=https://raw.githubusercontent.com/open-traffic-generator/models/rsvp_ero/artifacts/openapi.yaml&nocors#tag/Configuration/operation/set_config)

In this example, there are two test ports connected to a System Under Test with multiple routers.
Test port1 is acting as the ingress for two uni-directional tunnels. Both the tunnels are originating from the loopback
interface on the device on port1 and terminating in the loopback of the device on port2 , which is also a test port. In between there
is a collection of routers under test which allow creation of LSPs to the same destination via multiple paths. One LSP is created with
auto ero enabled while the other LSP carries a static user configured ERO.

                        |---------Rtr2 (11.11.11.1)--------
                        |                                 |
(Ingress) p1 ------rtr1                                  rtr4-----p2 (Egress)
  7.7.7.7/auto ero            |                                    |           8.8.8.8
                        |---------Rtr3 (12.12.12.1)--------
    
   

# python snappi
#Creating Ports
import otg

api = otg.api(location="https://localhost")
config = api.config()
p1 = config.ports.port(name='p1', location='172.17.0.2:50071')[-1]
p2 = config.ports.port(name='p2', location='172.17.0.3:50071')[-1]

#Create RSVP running on connected interface.

p1_d1 = config.devices.device(name='p1_d1')[-1]
p2_d1 = config.devices.device(name='p2_d1')[-1]

p1_eth1 = p1_d1.ethernets.ethernet()[-1]
p2_eth1 = p2_d1.ethernets.ethernet()[-1]

p1_eth1.connection.choice = 1
p1_eth1.connection.port_name = p1.name

p2_eth1.connection.choice = 1
p2_eth1.connection.port_name = p2.name

p1_eth1.name ='p1_eth1'
p1_eth1.mac = '00:11:00:00:00:01'
p1_ip1 = p1_eth1.ipv4_addresses.ipv4(name = 'p1_ip1', address = '20.20.20.2', gateway = '20.20.20.1')[-1]
p1_lo1 = p1_d1.ipv4_loopbacks.ipv4loopback(eth_name = p1_eth1.name,name = 'p1_lo1', address = '7.7.7.7')[-1]

p2_eth1.name='p2_eth1'
p2_eth1.mac = '00:12:00:00:00:01'
p2_ip1 = p2_eth1.ipv4_addresses.ipv4(name='p2_ip1', address = '30.30.30.2', gateway = '30.30.30.1')[-1]
p2_lo1 = p2_d1.ipv4_loopbacks.ipv4loopback(eth_name = p2_eth1.name,name='p2_lo1', address = '8.8.8.8')[-1]

p1_rsvpRtr1 = p1_d1.rsvp
p2_rsvpRtr1 = p2_d1.rsvp

p1_rsvpRtr1.name='p1_d1_rsvp'
p2_rsvpRtr1.name='p2_d1_rsvp'

p1_rsvpInf1 = p1_rsvpRtr1.ipv4_interfaces.ipv4interface(ipv4_name=p1_ip1.name,neighbor_ip = '20.20.20.1',enable_refresh_reduction = True, send_bundle = True)[-1]
p2_rsvpInf1 = p2_rsvpRtr1.ipv4_interfaces.ipv4interface(ipv4_name=p2_ip1.name,neighbor_ip = '21.21.21.1',enable_refresh_reduction = True, send_bundle = True)[-1]

#egress lsp port 2
p2_rsvpLspInf1 = p2_rsvpRtr1.lsp_ipv4_interfaces.lspipv4interface(ipv4_name=p2_lo1.name)[-1]
p2_rsvpLspInf1.p2p_egress_ipv4_lsps.name = "egress1"
p2_rsvpLspInf1.p2p_egress_ipv4_lsps.enable_fixed_label = True
# setting ipv4 explicit null label
p2_rsvpLspInf1.p2p_egress_ipv4_lsps.fixed_label_value = 0

#here we are creating 2 tunnels, each with 1 lsp(with default lsp_id = 1),to an egress endpoint 8.8.8.8.
#The 1st tunnel configured via DUT 10.10.10.1 and the 2nd one through different DUT 20.20.20.1
#The 1st tunnel is also configured to use a non zero traffic bandwidth by configuring token bucket rate

#port 1 ingress lsp 1
p1_rsvpLspInf1 = p1_rsvpRtr1.lsp_ipv4_interfaces.lspipv4interface(ipv4_name=p1_lo1.name)[-1]
p1_rsvpIngressLsp1 = p1_rsvpLspInf1.p2p_ingress_ipv4_lsps.p2pingressipv4lsp(remote_address = '8.8.8.8',name = "lsp1", tunnel_id = 1)[-1]
p1_rsvpIngressLsp1.tspec.token_bucket_rate = 100000
p1_rsvpIngressLsp1.tspec.peak_data_rate = 10000
p1_rsvpIngressLsp1.tspec.token_bucket_size = 10000
p1_rsvpIngressLsp1.session_attribute.auto_generate_session_name = False
p1_rsvpIngressLsp1.session_attribute.session_name = 'tunnel1'
p1_rsvpIngressLsp1.session_attribute.resource_affinities.exclude_any = 'F000'
p1_rsvpIngressLsp1.ero.choice = "auto"

#port 1 ingress lsp 2
p1_rsvpIngressLsp2 = p1_rsvpLspInf1.p2p_ingress_ipv4_lsps.p2pingressipv4lsp(remote_address = '8.8.8.8',name = "lsp2",tunnel_id = 2)[-1]
p1_rsvpIngressLsp2.ero.prepend_neighbor_ip = 'prepend_strict'
p1_rsvpIngressLsp2.session_attribute.resource_affinities.include_any = '7000000A'
p1_rsvpIngressLsp2.ero.choice = "manual"
p1_rsvpIngressLsp2.ero.prepend_neighbor_ip = 'dont_prepend'
p1_rsvpIngressLsp2.ero.subobjects.subobject(ipv4_address = '12.12.12.1')[-1]

print(config.serialize())

{
  "devices": [
    {
      "ethernets": [
        {
          "connection": {
            "choice": "port_name",
            "port_name": "p1"
          },
          "ipv4_addresses": [
            {
              "address": "20.20.20.2",
              "gateway": "20.20.20.1",
              "name": "p1_ip1",
              "prefix": 24
            }
          ],
          "mac": "00:11:00:00:00:01",
          "mtu": 1500,
          "name": "p1_eth1"
        }
      ],
      "ipv4_loopbacks": [
        {
          "address": "7.7.7.7",
          "eth_name": "p1_eth1",
          "name": "p1_lo1"
        }
      ],
      "name": "p1_d1",
      "rsvp": {
        "ipv4_interfaces": [
          {
            "bundle_threshold": 50,
            "enable_hello": false,
            "enable_refresh_reduction": true,
            "hello_interval": 9,
            "ipv4_name": "p1_ip1",
            "label_space_end": 100000,
            "label_space_start": 1000,
            "neighbor_ip": "20.20.20.1",
            "send_bundle": true,
            "summary_refresh_interval": 30,
            "timeout_multiplier": 3
          }
        ],
        "lsp_ipv4_interfaces": [
          {
            "ipv4_name": "p1_lo1",
            "p2p_ingress_ipv4_lsps": [
              {
                "backup_lsp_id": 2,
                "ero": {
                  "choice": "auto",
                  "prefix_length": 32,
                  "prepend_neighbor_ip": "prepend_loose"
                },
                "lsp_id": 1,
                "lsp_switchover_delay": 0,
                "name": "lsp1",
                "refresh_interval": 30,
                "remote_address": "8.8.8.8",
                "session_attribute": {
                  "auto_generate_session_name": false,
                  "bandwidth_protection_desired": false,
                  "holding_priority": 7,
                  "label_recording_desired": false,
                  "local_protection_desired": false,
                  "node_protection_desired": false,
                  "resource_affinities": {
                    "exclude_any": "F000",
                    "include_all": "0",
                    "include_any": "0"
                  },
                  "se_style_desired": false,
                  "session_name": "tunnel1",
                  "setup_priority": 7
                },
                "timeout_multiplier": 3,
                "tspec": {
                  "maximum_policed_unit": 0,
                  "minimum_policed_unit": 0,
                  "peak_data_rate": 10000,
                  "token_bucket_rate": 100000,
                  "token_bucket_size": 10000
                },
                "tunnel_id": 1
              },
              {
                "backup_lsp_id": 2,
                "ero": {
                  "choice": "manual",
                  "prefix_length": 32,
                  "prepend_neighbor_ip": "dont_prepend",
                  "subobjects": [
                    {
                      "as_number": 0,
                      "hop_type": "loose",
                      "ipv4_address": "12.12.12.1",
                      "prefix_length": 32,
                      "type": "ipv4"
                    }
                  ]
                },
                "lsp_id": 1,
                "lsp_switchover_delay": 0,
                "name": "lsp2",
                "refresh_interval": 30,
                "remote_address": "8.8.8.8",
                "session_attribute": {
                  "auto_generate_session_name": true,
                  "bandwidth_protection_desired": false,
                  "holding_priority": 7,
                  "label_recording_desired": false,
                  "local_protection_desired": false,
                  "node_protection_desired": false,
                  "resource_affinities": {
                    "exclude_any": "0",
                    "include_all": "0",
                    "include_any": "7000000A"
                  },
                  "se_style_desired": false,
                  "setup_priority": 7
                },
                "timeout_multiplier": 3,
                "tunnel_id": 2
              }
            ]
          }
        ],
        "name": "p1_d1_rsvp"
      }
    },
    {
      "ethernets": [
        {
          "connection": {
            "choice": "port_name",
            "port_name": "p2"
          },
          "ipv4_addresses": [
            {
              "address": "30.30.30.2",
              "gateway": "30.30.30.1",
              "name": "p2_ip1",
              "prefix": 24
            }
          ],
          "mac": "00:12:00:00:00:01",
          "mtu": 1500,
          "name": "p2_eth1"
        }
      ],
      "ipv4_loopbacks": [
        {
          "address": "8.8.8.8",
          "eth_name": "p2_eth1",
          "name": "p2_lo1"
        }
      ],
      "name": "p2_d1",
      "rsvp": {
        "ipv4_interfaces": [
          {
            "bundle_threshold": 50,
            "enable_hello": false,
            "enable_refresh_reduction": true,
            "hello_interval": 9,
            "ipv4_name": "p2_ip1",
            "label_space_end": 100000,
            "label_space_start": 1000,
            "neighbor_ip": "21.21.21.1",
            "send_bundle": true,
            "summary_refresh_interval": 30,
            "timeout_multiplier": 3
          }
        ],
        "lsp_ipv4_interfaces": [
          {
            "ipv4_name": "p2_lo1",
            "p2p_egress_ipv4_lsps": {
              "enable_fixed_label": true,
              "fixed_label_value": 0,
              "name": "egress1",
              "refresh_interval": 30,
              "reservation_style": "shared_explicit",
              "timeout_multiplier": 3
            }
          }
        ],
        "name": "p2_d1_rsvp"
      }
    }
  ],
  "ports": [
    {
      "location": "172.17.0.2:50071",
      "name": "p1"
    },
    {
      "location": "172.17.0.3:50071",
      "name": "p2"
    }
  ]
}