YDK tutorial

[Guan Deng]

hi people,

How can i find any good tutorial for if i want to put the following YANG Oper data from cisco XR devices?

yang/Cisco-IOS-XR-plat-chas-invmgr-oper.yang at master · YangModels/yang · GitHub

what i want to do is to get the inventory data in XML format and put them in a file...

Cheers

Guan

[einarnn]

Guan,

We don’t currently support a version of the YDK that has IOS-XR 5.3.4 models in it. Have you tried direct a direct NETCONF get? You might try the utility ncc.py, found here (recommend pulling entire git repo):

https://github.com/CiscoDevNet/ncc/blob/master/ncc.py

Something like this should work once you’ve downloaded it and installed its dependencies:

python ncc.py --host=your-device-ip -u your-username -p your-password --get-oper \

-f ‘<platform-inventory xmlns=“http://cisco.com/ns/yang/Cisco-IOS-XR-plat-chas-invmgr-oper">'

This will dump XML to your console, and you can either use this as a CLI utility, or copy the use of the python ncclient library to your own code.

Cheers,

Einar

[Guan Deng]

hi Nilsen,

many thanks!

I got the packet installed, but i am getting this:

(v)vagrant@vagrant-ubuntu-trusty-64:~/ncc$ python ncc.py --host=1.1.1.1 -u vagrant -p vagrant --get-oper  -f ‘<platform-inventory xmlns=“http://cisco.com/ns/yang/Cisco-IOS-XR-plat-chas-invmgr-oper">'

> °°

> <<

> >>>

> >ff

> >

>

>

seems the command is not finished and i was stuck in >

Cheers

Guan

[einarnn]

Guan,

If you copied & pasted from your web browser or email, please make sure that no unicode quote characters got copied from the website. That can mess things up when ingested by the shell and provide bad input to Python.

Looking at what I see in the email below, there is two wrong characters, and they may have come from my original posting, apologies.

Cheers,

Einar

[Guan Deng]

hi Einar,

my filter is still not correct:

python ncc.py --host=1.1.1.1 -u vagrant -p vagrant --get-oper -f <platform-inventory xmlns=“http://cisco.com/ns/yang/Cisco-IOS-XR-plat-chas-invmgr-oper">

>

where do i do wrong?

[einarnn]

Put single quotes around the whole XML tag for platform inventory:

python ncc.py --host=1.1.1.1 -u vagrant -p vagrant --get-oper -f '<platform-inventory xmlns=“http://cisco.com/ns/yang/Cisco-IOS-XR-plat-chas-invmgr-oper”/>'

Without that single quotes, the parameter given to -f isn’t correctly formed.

Cheers,

Einar

[saalvare · Accepted solution]

Guan,

Regarding your original question, the NANOG 68 YDK talk will give you a bit of a tutorial:

NANOG 68: YDK overview / demo

You can find a sample app to read the inventory, validate the data, encode it in XML and print output at:

nc-read-xr-plat-chas-invmgr-oper-99-ydk.py · GitHub

You can invoke it using:

$ ./nc-read-xr-plat-chas-invmgr-oper-99-ydk.py ssh://user:password@host

Hope that help!

[Guan Deng]

Hi Santiago,

Thanks a lot, this helps.

We figured it out at the end the filter was wrong, it should be looking like this:

(v)vagrant@vagrant-ubuntu-trusty-64:~/ncc$ python ncc.py --host=1.1.1.1 -u vagrant -p vagrant --get-oper -f '<platform xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-plat-chas-invmgr-oper">'

For BGP Oper as example:

(v)vagrant@vagrant-ubuntu-trusty-64:~/ncc$ python ncc.py --host=1.1.1.1 -u vagrant -p vagrant --get-oper -f "<bgp xmlns='http://cisco.com/ns/yang/Cisco-IOS-XR-ipv4-bgp-oper'><instances><instance><instance-name>default</instance-name><instance-active><default-vrf><neighbors><neighbor><neighbor-address/></neighbor></neighbors></default-vrf></instance-active></instance></instances></bgp>"

This is much more tedious of cause, but i think it helps to understand how to build a filter.

Cheers

Guan

[saalvare]

IMHO, if you're having to handcraft filters, you're doing it wrong.  The whole YDK purpose is to abstract as much as possible these details.  I agree that at the end it all comes to personal preference.  Glad you got it working.

[Guan Deng]

thanks Santiago, really appreciated