extend has problem in Cisco_IOS_XR_mpls_vpn_oper

[magedahmed]

I am trying to use "extend to add two values under "Cisco_IOS_XR_mpls_vpn_oper.L3vpn.Vrfs.Vrf.Interface()" to add two interface to the list but when I am trying to encode I can see only one value appear

I also tried append interface1 then interface2 but I got the same result

below the code I am using

import time
import datetime

from ydk.models.cisco_ios_xr import Cisco_IOS_XR_mpls_vpn_oper
from ydk.services import CodecService
from argparse import ArgumentParser
from ydk.providers import CodecServiceProvider

#print(dir(Cisco_IOS_XR_mpls_vpn_oper.L3vpn.Vrfs))
start = time.time()
class l3vpn_ydk_oper_object():
    def __init__(self):
        self.l3vpn = Cisco_IOS_XR_mpls_vpn_oper.L3vpn()
        self.vrfs = Cisco_IOS_XR_mpls_vpn_oper.L3vpn.Vrfs()

    def l3vpn_fun(self, vrf_name, RD, interfaces):
        vrf = Cisco_IOS_XR_mpls_vpn_oper.L3vpn.Vrfs.Vrf()
        vrf.vrf_name = vrf_name

        af = Cisco_IOS_XR_mpls_vpn_oper.L3vpn.Vrfs.Vrf.Af()
        af.af_name = Cisco_IOS_XR_mpls_vpn_oper.MplsVpnAfi.ipv4 #MplsVpnAfiEnum.ipv4
        af.export_route_policy = 'y'
        af.import_route_policy = 'x'
        af.saf_name = Cisco_IOS_XR_mpls_vpn_oper.MplsVpnSafi.unicast #MplsVpnSafiEnum.unicast
        vrf.af.append(af)

        interface1 = Cisco_IOS_XR_mpls_vpn_oper.L3vpn.Vrfs.Vrf.Interface()
        interface1.interface_name = interfaces[0]
        interface2 = Cisco_IOS_XR_mpls_vpn_oper.L3vpn.Vrfs.Vrf.Interface()
        interface2.interface_name = interfaces[1]
        vrf.interface.extend([interface2, interface1])

        vrf.route_distinguisher = RD
        vrf.vrf_name_xr = vrf_name
        self.vrfs.vrf.append(vrf)


    def return_l3vpn(self):
        self.l3vpn.vrfs = self.vrfs
        return self.l3vpn

if __name__ == "__main__":
    """Execute main program."""
    parser = ArgumentParser()
    parser.add_argument("-v", "--verbose", help="print debugging messages",
                        action="store_true")
    args = parser.parse_args()

    # log debug messages if verbose argument specified
    if args.verbose:
        logger = logging.getLogger("ydk")
        logger.setLevel(logging.INFO)
        handler = logging.StreamHandler()
        formatter = logging.Formatter(("%(asctime)s - %(name)s - "
                                      "%(levelname)s - %(message)s"))
        handler.setFormatter(formatter)
        logger.addHandler(handler)

    # create codec provider
    provider = CodecServiceProvider(type="json")

    # create codec service
    codec = CodecService()

    l3vpn_info = l3vpn_ydk_oper_object()  # create object
    l3vpn_list = ['vrf_red',"192.168.111.117:41",['gi1/1','gi1/2']]
    l3vpn_info.l3vpn_fun(l3vpn_list[0],l3vpn_list[1],l3vpn_list[2])

    # encode and print object
    print(codec.encode(provider, l3vpn_info.return_l3vpn()))

    end = time.time()
    print("Total time: {}".format(end - start))
    exit()

 below the encoding output

{
  "Cisco-IOS-XR-mpls-vpn-oper:l3vpn": {
    "vrfs": {
      "vrf": [
        {
          "vrf-name": "vrf_red",
          "vrf-name-xr": "vrf_red",
          "route-distinguisher": "192.168.111.117:41",
          "interface": [
            {
              "interface-name": "gi1/2"
            }
          ],
          "af": [
            {
              "af-name": "ipv4",
              "saf-name": "unicast",
              "import-route-policy": "x",
              "export-route-policy": "y"
            }
          ]
        }
      ]
    }
  }
}

[ygorelik]

It is actually not 'extend' issue, but YDK CodecService failure to encode keyless lists. Thank you for finding this bug. I have opened the corresponding GitHub issue to track its resolution.

[magedahmed]

@ygorelik

Could you please help by providing a ydk code fix on github so I can use it.

[ygorelik · Accepted solution]

Hi magedahmed
I have resolved the bug for C++ and Python. The fix is too complex, going to the foundation of YDK. Therefore it will be available in the next YDK release (0.8.1).
In the meanwhile I can suggest you to use XmlSubtreeCodec (add parameter 'subtree'), which functions outside of libyang library, which is obviously can be used only for XML encoding. You will need to encode the entity to XML and then convert to JSON. I am sure there are some third party packages that can help to do that.
Your actionable part of the script will look like this:
# create codec provider and service
provider = CodecServiceProvider(type="xml")
codec = CodecService()
xml = codec.encode(provider, l3vpn_info.return_l3vpn(), subtree=True)
print(xml)

The result will look like this:







vrf_red

vrf_red

192.168.111.117:41



ipv4

unicast

x

y





gi1/2





gi1/1









Other alternative, which currently works for both XML and JSON encoding, is to use Path API. Please let me know if you need help here.

[magedahmed]

Hi ygorelik,

Many thanks for your support I tried on YDK release (0.8.1) and it is working fine

[ygorelik]

Hi magedahmed
As of today the issue is completely resolved, meaning the solution was applied across all YDK supported encoding, languages and platforms. The complete solution will be available in new YDK release (0.8.1), which most likely will be in February. But in the meanwhile you can use some workarounds, which were described in my previous post.
Thanks,
Yan

[magedahmed]

I used YDK 0.8.1 from your github and problem solved even with json.
Many thanks for your support