The YANG (Yet Another Next Generation) data modeling language is widely used in network configuration and data representation. This tutorial guides you through the installation and use of pyang, a YANG validator, converter, and code generator, to inspect the YANG info for Nokia 7×50 models.

Step 1: Setting up a Virtual Environment

First, we’ll set up a virtual environment to keep our working space isolated.

• Make sure you have python3 and git installed.
• Create a new virtual environment using for example:

mkdir pyang
cd pyang
python3 -m venv .
source ./bin/activate

Step 2: Installing pyang

• Now, within our activated virtual environment, we’ll install pyang.

pip3 install pyang

Step 3: Cloning Nokia 7×50 YANG Models from GitHub

Clone the repository containing the models.

git clone https://github.com/nokia/7x50_YangModels.git

Now you have all the Yang files and releases. Change into the appropriate directory like the following:

cd 7x50_YangModels/latest_sros_23.3/nokia-combined

Step 4: Using pyang to Inspect the YANG Info

We’ll now use pyang to inspect the specific path /configure/router/pcep/pcc within the nokia-conf.yang model.

pyang nokia-conf.yang -f tree --tree-path '/configure/router/pcep/pcc' --tree-depth 6

Output:

module: nokia-conf
  +--rw configure
     +--rw router* [router-name]
        +--rw pcep
           +--rw pcc!
              +--rw ...
              ...
              +--rw pce-associations
                 +--rw diversity* [assoc-name]
                 |     ...
                 +--rw policy* [assoc-name]
                       ...

This output provides a tree representation of the nokia-conf.yang module, focusing on the path /configure/router/pcep/pcc.

Wrapping up

You’ve now learned how to set up a virtual environment, install pyang, clone the Nokia 7×50 YANG models, and use pyang to inspect a specific YANG model path. This is essential for understanding the structure and details of YANG models, which can be invaluable when configuring or understanding network devices and systems.

See ya!