Yang Tools

Here’s some information about various tools for working with yang models.

yanglint cheat sheet

libyang project includes a feature-rich tool called yanglint(1) for validation and conversion of the schemas and YANG modeled data. The source codes are located at /tools/lint and can be used to explore how an application is supposed to use the libyang library. yanglint(1) binary as well as its man page are installed together with the library itself.

Validate a YANG module:

$ yanglint -p <yang-search-path> module.yang

Generate tree representation of a YANG module:

$ yanglint -p <yang-search-path> -f tree module.yang

Validate JSON/XML instance data:

$ yanglint -p <yang-search-path> module.yang data.{json,xml}

Convert JSON/XML instance data to another format:

$ yanglint -p <yang-search-path> -f xml module.yang data.json
$ yanglint -p <yang-search-path> -f json module.yang data.xml

yanglint also features an interactive mode which is very useful when needing to validate data from multiple modules at the same time. The yanglint README provides several examples: https://github.com/CESNET/libyang/blob/master/tools/lint/examples/README.md

Man page (groff): https://github.com/CESNET/libyang/blob/master/tools/lint/yanglint.1

pyang cheat sheet

pyang is a YANG validator, transformator and code generator, written in python. It can be used to validate YANG modules for correctness, to transform YANG modules into other formats, and to generate code from the modules.

Obtaining and installing pyang:

$ git clone https://github.com/mbj4668/pyang.git
$ cd pyang/
$ sudo python setup.py install

Validate a YANG module:

$ pyang --ietf -p <yang-search-path> module.yang

Generate tree representation of a YANG module:

$ pyang -f tree -p <yang-search-path> module.yang

Indent a YANG file:

$ pyang -p <yang-search-path> \
    --keep-comments -f yang --yang-canonical \
    module.yang -o module.yang

Generate skeleton instance data:

  • XML:

    $ pyang -p <yang-search-path>

    -f sample-xml-skeleton –sample-xml-skeleton-defaults module.yang [augmented-module1.yang …] -o module.xml

  • JSON:

    $ pyang -p <yang-search-path>

    -f jsonxsl module.yang -o module.xsl

    $ xsltproc -o module.json module.xsl module.xml

Validate XML instance data (works only with YANG 1.0):

$ yang2dsdl -v module.xml module.yang


YANG syntax highlighting for vim: https://github.com/nathanalderson/yang.vim