Some tools can help you to check your YANG documents and YANG modules. The document "Guidelines for Authors and Reviewers of YANG Data Model Documents" [RFC8407] for example, requires that a YANG module adhere to the syntax rules of YANG 1 or YANG 1.1.
There is no requirement that a YANG module passes a specific YANG compiler. The requirement is that the syntax is correct.
So the following is not a promotion of any specific tool, but rather a pointer to a tool that is used by YANG reviewers:
pyang
pyang is an open source tool, which can be downloaded at https://github.com/mbj4668/pyangpyang has a flag --ietf that checks RFC8407 rules.yanglint
yanglint is an open source tool, part of the libyang project, which can be downloaded at https://github.com/CESNET/libyangyangvalidator.com
The RFC editor ensures that all published YANG modules are formatted consistently. To facilitate reviews and lessen the RFC Editor task, authors are recommended to format the modules in Internet Drafts. The RFC editor currently uses pyang to do the formatting. Use the following commands:
# ensure that the module fits into the line limits of an I-D
pyang --ietf --max-line-length 69 FILE
# format the module
pyang -f yang --keep-comments --yang-line-length 69 FILE
The first tool is a python function, xym, which is used to extract all the YANG modules out of a internet-draft. xym is open source, available from https://github.com/YangModels/yang/tree/master/tools/xym.
./xym.py -h
usage: xym.py [-h] [--srcdir SRCDIR] [--dstdir DSTDIR] [--strict STRICT]
[--debug DEBUG]
source
Extract model out of an IETF RFC or draft
positional arguments:
source The URL or file name of the RFC/draft text from which to
get the model
optional arguments:
-h, --help show this help message and exit
--srcdir SRCDIR Optional directory where to find the source text.Default is
'./'
--dstdir DSTDIR Optional directory where to put the extracted yang
module(s)Default is './'
--strict STRICT Optional flag that determines syntax enforcement; 'If set
to 'True' <CODE BEGINS> / <CODE ENDS> are required; default
is 'False'
--debug DEBUG Debug level; default is 0
The second tool is rfcstrip, which is used to extract all the YANG modules out of a internet-draft. rfcstrip is open source, available from https://github.com/mbj4668/rfcstrip.
rfcstrip <internet-draft-file-name>
The resulting YANG module(s) can then be fed into the pyang or yanglint program for syntax checking, and compliance with [RFC8407]:
pyang --ietf <yang-file-name>
yanglint <yang-file-name>
Last changed on April 29th, 2014 by Benoit Claise
The content of this page was last updated on 2021-10-20. It was migrated from the old Trac wiki on 2022-12-20.