topic issue with retrieving of schema in Tools

issue with retrieving of schema

aligang1988 — Thu, 17 May 2018 12:55:49 GMT

Hi
I could generate bundle using ydk-gen 3rd party vendor yang models without facing any obvious problems.
Then I imported it, made small testing code(attached) and faced and issue.

As it seem from debug (attached), crud tries to download yang-model in order to validate payload against it. It makes several iterations and then returns error
ydk.errors.YInvalidArgumentError: Path is invalid: configuration:configuration

However pasting of below-listed rpc over ssh returned yang model

ssh 192.168.2.11 -p 830 -l ali -s netconf

Password:

<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="1">

<get-schema>

<module>configuration</module>

</get-schema>

</rpc>

Q: Could you please explain how crud composes rpc to fetch schemes (it seems it tries to put "configuration:confguration" between "module" tags instead of "configuration"). Is it possible to influence on this logic somehow or disable this sort of validation ?

Thanks a lot !

Re: issue with retrieving of schema

abhirame — Fri, 18 May 2018 17:06:31 GMT

It appears that the device does not support the get-schema RPC. Can you please copy all the device yang models to the below directory:

/home/alex-limonov/.ydk/192.168.2.11_830

The other option is to pass in a different folder location of the yang models in the repo parameter of NetconfServiceProvider: http://ydk.cisco.com/py/docs/api/providers/netconf_provider.html#ydk.providers.NetconfServiceProvider

Re: issue with retrieving of schema

aligang1988 — Sat, 19 May 2018 20:30:23 GMT

Thanks for you responce
Actually I could send get-schema RPC over SSH (simple openssh connection) !
i used such command :
cat get-schema_request.xml | ssh 192.168.2.11 -p 830 -l ali -s netconf >> get-schema_responce.xml (respective .xml files are in attachement)

That makes me think that get-schema RPC was processed normally by device.

What is little bit strange:
When test-code is executed there is no get-schema-rpc message in debug, only comments, that it tries to fetch schema from device (however hello messages bodies do present and another ydk specific debugs do present).Libssh and libnetconf were rebuilt to provide logging.

Is there option to check that get-schema rpc was actually sent ? Because right now it is not really obvious

From the other hand, manual specifying of repo with .yang files breaks a knot, but I would like to understand why my code can not fetch and resolve yang models directly from device

Re: issue with retrieving of schema

aligang1988 — Sat, 19 May 2018 21:06:55 GMT

Small update:

I have slightly modified test code and ran it over XR platform.
Below is displayed respective debug and it does content get-schema-rpc body

Connected to 192.168.2.12 on port 22 using ssh with timeout of -1
Executing CRUD update operation on [Cisco-IOS-XR-ifmgr-cfg:interface-configurations]
Getting new modules for ydk:update
Getting new modules for ydk:update
Loading Module 'ydk' Revision ''
Cache hit Module 'ydk' Revision ''
Getting new modules for Cisco-IOS-XR-ifmgr-cfg:interface-configurations
Getting new modules for Cisco-IOS-XR-ifmgr-cfg:interface-configurations
Loading Module 'Cisco-IOS-XR-ifmgr-cfg' Revision ''
Getting module Cisco-IOS-XR-ifmgr-cfg submodule none
Looking for file in folder: /home/alex-limonov/.ydk/192.168.2.12_22
Opening file /home/alex-limonov/.ydk/192.168.2.12_22/Cisco-IOS-XR-ifmgr-cfg.yang
Path found with rev: false. Path without rev: false
Getting module using get-schema Cisco-IOS-XR-ifmgr-cfg
Trace: Missing message-id in rpc.
Netconf SSH Client: sending rpc
Trace: Writing message (session 2665454158): <?xml version="1.0"?>
<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="1">
<get-schema xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-monitoring">
<identifier>Cisco-IOS-XR-ifmgr-cfg</identifier>
<format>yang</format>
</get-schema>
</rpc>

This is extract from initial debug, it looks pretty similar to previous one until string 15. It says "Cannot find model with module_name: configuration module_rev"

Connected to 192.168.2.11 on port 830 using ssh with timeout of -1
Executing CRUD create operation on [configuration:configuration]
Getting new modules for ydk:create
Getting new modules for ydk:create
Loading Module 'ydk' Revision ''
Cache hit Module 'ydk' Revision ''
Getting new modules for configuration:configuration
Getting new modules for configuration:configuration
Loading Module 'configuration' Revision ''
Getting module configuration submodule none
Looking for file in folder: /home/alex-limonov/.ydk/192.168.2.11_830
Opening file /home/alex-limonov/.ydk/192.168.2.11_830/configuration.yang
Path found with rev: false. Path without rev: false
Getting module using get-schema configuration
Cannot find model with module_name: configuration module_rev:
Debug: Searching for "configuration" in /home/alex-limonov/.ydk/192.168.2.11_830.
Debug: Searching for "configuration" in /home/alex-limonov/ydk/trash.
Data is invalid according to the yang model. Error details: Data model "configuration" not found.

Q: Could you please explain, what actually it tries to check here ?

Thanks !

Re: issue with retrieving of schema

abhirame — Mon, 21 May 2018 16:52:26 GMT

Sorry. It looks like though the device supports get-schema, it does not advertise the support for the corresponding model "ietf-netconf-monitoring" in the capabilities in the hello message. This needs to be fixed on the device side