Yuma yangdiff Manual

YANG-Based Unified Modular Automation Tools

YANG Module Compare Tool

Version 1.15

Last Updated:  July 20, 2011

Table Of Contents

1 Preface

1.1 Legal Statements

Copyright 2009 - 2011 Andy Bierman,  All Rights Reserved.

1.2 Additional Resources

This document assumes you have successfully set up the software as described in the printed document:

Yuma  Installation Guide

Other documentation includes:

Yuma  Quickstart Guide

Yuma  User Manual

Yuma netconfd  Manual

Yuma yangcli Manual

Yuma yangdump Manual

Yuma Developer Manual

To obtain additional support you may join the yuma-users group on sourceforge.net and send email to this e-mail address:

yuma-users@lists.sourceforge.net

The SourceForge.net Support Page for Yuma can be found at this WEB page:

http://sourceforge.net/projects/yuma/support

There are several sources of free information and tools for use with YANG and/or NETCONF.

The following section lists the resources available at this time.

1.2.1 WEB Sites

• Netconf Central

  • http://www.netconfcentral.org/

  • Yuma Home Page

    • Free information on NETCONF and YANG, tutorials, on-line YANG module validation and documentation database

• Yuma SourceFource OpenSource Project

  • http://sourceforge.net/projects/yuma/

    • Download Yuma source and binaries; project forums and help

• Yang Central

  • http://www.yang-central.org

  • Free information and tutorials on YANG, free YANG tools for download

• NETCONF Working Group Wiki Page

  • http://trac.tools.ietf.org/wg/netconf/trac/wiki

  • Free information on NETCONF standardization activities and NETCONF implementations

• NETCONF WG Status Page

  • http://tools.ietf.org/wg/netconf/

  • IETF Internet draft status for NETCONF documents

• libsmi Home Page

  • http://www.ibr.cs.tu-bs.de/projects/libsmi/

  • Free tools such as smidump, to convert SMIv2 to YANG

1.2.2 Mailing Lists

• NETCONF Working Group

  • http://www.ietf.org/html.charters/netconf-charter.html

  • Technical issues related to the NETCONF protocol are discussed on the NETCONF WG mailing list.  Refer to the instructions on the WEB page for joining the mailing list.

• NETMOD Working Group

  • http://www.ietf.org/html.charters/netmod-charter.html

  • Technical issues related to the YANG language and YANG data types are discussed on the NETMOD WG mailing list.  Refer to the instructions on the WEB page for joining the mailing list.

1.3  Conventions Used in this Document

The following formatting conventions are used throughout this document:

Documentation Conventions

2 yangdiff User Guide

2.1 Introduction

The yangdiff program is used to compare two revisions of the same YANG file.  

2.1.1 Features

The yangdiff program has the following features:

• The conceptual YANG object trees are compared, not the actual YANG statements.

• Two separate subtrees of modules can be compared, not just 1 file at a time.

• The differences report format for differences is easy to read, and can be configured with 2 different levels of verbosity.

• A YANG revision statement can be automatically generated instead of a list of differences.  This will include an English text summary of the differences found.

2.1.2 Starting yangdiff

The current working directory in use when yangdiff is invoked is important.  It is most convenient to run yangdiff from a work directory, rather than the installation directory or within the module library.

The yangdiff program can be invoked several ways:

• To get the current version and exit:

   

yangdiff --version

•  

• To get program help and exit:

   

yangdiff --help

yangdiff --help --brief

yangdiff --help --full

•  

• To compare a new YANG module named 'foo', with an old version named foo.2008-09-01.yang, the following command line can be used

   

yangdiff --old=foo.2008-09-01.yang --new=foo

•  

• To get all the configuration parameters from a text file named '~/yangdiff-project1.conf':

   

yangdiff --config=~/yangdiff-project1.conf

•  

• To generate a terse differences report called ~/project-X-diffs.log for  the old files in the '/public/project-X/modules' with the new modules in the '~/work' directory:

   

yangdiff --difftype=terse
--output=~/project-X-diffs.log \

--old=/public/project-X/modules \

--new=/work

•  

• To generate a revision statement differences to ~/foo-projectX-revision.txt for  the '~/work/foo.yang' module, with the old version in the in the  '/public/project-X/modules':

   

yangdiff --difftype=revision
--output=~/foo-project-X-revision.txt \

--old=/public/project-X/modules \

--new=/work/foo.yang

2.1.3 Stopping yangdiff

There is no interactive mode for yangdiff, so there is no need for a command to exit the program.

The Control C character sequence can be used to cancel the yangdiff processing in progress.  However, this will leave any partially completed output files in place.

2.1.4 Configuration Parameter List

The following configuration parameters are used by yangdiff.  Refer to the CLI Reference for more details.

yangdiff CLI Parameters

2.2 Comparing YANG Modules

The yangdiff program compares YANG files in the following maner:

• The cooked object trees are compared, not the actual YANG statements.

• Whitespace differences are ignored.

• Non-semantic changes are ignored:

  • A uses-stmt can replace a set of objects if the grouping is identical to the old objects.

  • Refine statements are combined into the cooked objects, and not compared directly.

  • A typedef statement can replace an inline type statement

  • Changes to YANG comments are ignored.

  • Sub-statement order is ignored, however object order with a container or list is not ignored.

  • Objects can be moved to submodules, and include statements instead.

If the --old parameter is missing, then the module search path will be used to find the specified module with the same name.  If the --old parameter contains just a module name, then the module search path will be used to find a module with the new name.

The --new parameter is required.  It can represent one YANG file or a directory of new YANG modules.

The --difftype parameter is optional.  The 'normal' report mode is used if this parameter is missing.

The --output parameter will be used for the report file, if it is specified.

2.3 Diff Reports

This section uses the example module below (test/test3a.yang) to demonstrate the different report formats available.  The old module revision is test/test3.yang.

The following command is used in all 3 examples, except the value of the --difftype parameter is changed each time.

yangdiff --old=test3a --new=test3 --difftype=<enum>

2.3.1 Terse Report

If --difftype=terse is selected, then a brief summary of all changes will be listed.  There will be no indentation, and only the change (Add, Modify, Delete), and the top-level definition is identified.

// Generated by yangdiff 0.9.7.473

// Copyright (c) 2009, Netconf Central, All Rights Reserved.

// old: test3 (2008-10-19) test3.yang

// new: test3 (2009-09-09) test3a.yang

D revision '2008-10-19'

A revision '2009-09-09'

A feature X

A identity testbase

A identity testbase1

M typedef C

D container test-D1

D leaf test-D

M container test33

2.3.2 Normal Report

If --difftype=normal is selected, then a complete summary of all changes will be listed.

If a change line is indented, it indicates a sub-statement of the object in the previous line has been changed.

// Generated by yangdiff 0.9.7.473

// Copyright (c) 2009, Netconf Central, All Rights Reserved.

// old: test3 (2008-10-19) test3.yang

// new: test3 (2009-09-09) test3a.yang

D revision '2008-10-19'

A revision '2009-09-09'

A feature X

A identity testbase

A identity testbase1

M typedef C

   M type

      M range from 'min .. 41 | 45' to 'min .. 41'

D container test-D1

D leaf test-D

M container test33

   D presence 'not a top-level mand...'

   M choice f

      M case f1

         M leaf f1

            A if-feature 'X'

2.3.3 Revision Statement

If --difftype=revision is selected, then a complete summary of all changes will be printed in the form of a YANG revision statement.  The current date will be used for the revision-date field of the revision statement.

// Generated by yangdiff 0.9.7.473

// Copyright (c) 2009, Netconf Central, All Rights Reserved.

// old: test3 (2008-10-19) test3.yang

// new: test3 (2009-09-09) test3a.yang

   revision 2009-09-10 {

      description "

         - Removed revision '2008-10-19'

         - Added revision '2009-09-09'

         - Added feature X

         - Added identity testbase

         - Added identity testbase1

         - Changed typedef C

            - Changed type

               - Changed range from 'min .. 41 | 45' to 'min .. 41'

         - Removed container test-D1

         - Removed leaf test-D

         - Changed container test33

            - Removed presence 'not a top-level mand...'

            - Changed choice f

               - Changed case f1

                  - Changed leaf f1

                     - Added if-feature 'X'

      ";

   }

3 CLI Reference

The yangdiff program uses command line interface (CLI) parameters to control program behavior.

The following sections document all the Yuma CLI parameters relevant to this program, in alphabetical order.

3.1 --config

The --config parameter specifies the name of a Yuma configuration file that contains more parameters to process, in addition to the CLI parameters.

Refer to the 'Configuration Files' section for details on the format of this file.

--config parameter

3.2 --difftype

The --difftype parameter controls how differences are displayed in the yangdiff program..

The allowed values are 'terse', 'normal', and 'revision'.

The basic report format is:

[add/delete/modify] field-name [field-value]

The 'terse' option will include the names of the top-level fields that are different.  The actual differences for modification lines ('M') are not printed.

M typedef C

D container test-D1

D leaf test-D

M container test33

The 'normal' option will  include any changes for any nested fields or objects.  A brief description of the changes made in a modification line ('M') are printed.  This is the default reporting mode.

M typedef C

   M type

      M range from 'min .. 41 | 45' to 'min .. 41'

D container test-D1

D leaf test-D

M container test33

   D presence 'not a top-level mand...'

   M choice f

      M case f1

         M leaf f1

            A if-feature 'X'

The 'revision' option will generate the differences report in YANG revision-stmt format.  For example:

  revision 2009-09-10 {

      description "

         - Changed typedef C

            - Changed type

               - Changed range from 'min .. 41 | 45' to 'min .. 41'

         - Removed container test-D1

         - Removed leaf test-D

         - Changed container test33

            - Removed presence 'not a top-level mand...'

            - Changed choice f

               - Changed case f1

                  - Changed leaf f1

                     - Added if-feature 'X'

      ";

   }

difftype parameter

3.3 --feature-disable

The --feature-disable parameter directs all programs to disable a specific feature.

This parameter is a formatted string containing a module name, followed by a colon ':', followed by a feature name, e.g.,

test:feature1

It is an error if a --feature-enable and --feature-disable parameter specify the same feature.

Parameters for unknown features will be ignored.

--feature-disable parameter

3.4 --feature-enable

The --feature-enable parameter directs all programs to enable a specific feature.

This parameter is a formatted string containing a module name, followed by a colon ':', followed by a feature name, e.g.,

test:feature1

It is an error if a --feature-disable and --feature-enable parameter specify the same feature.

Parameters for unknown features will be ignored.

--feature-enable parameter

3.5 --feature-enable-default

The --feature-enable-default parameter controls how yangdump will generate C code for YANG features by default.

If 'true', then by default, features will be enabled.

If 'false', then by default, features will be disabled.

If a --feature-enable or --feature-disable parameter is present for a specific feature, then this parameter will be ignored for that feature.

--feature-enable-default parameter

3.6 --header

The --header parameter controls whether YANG header contents will be compared in the yangdiff program.

--header parameter

3.7 --help

The --help parameter causes program help text to be printed, and then the program will exit instead of running as normal.

This parameter can be combined with the --help-mode parameter to control the verbosity of the help text.  Use --brief for less, and --full for more than the normal verbosity.

This parameter can be combined with the --version parameter in all programs.  It can also be combined with the --show-errors parameter in yangdump.

The program configuration parameters will be displayed in alphabetical order, not in schema order.

--help parameter

3.8 --help-mode

The --help-mode parameter is used to control the amount of detail printed when help text is requested in some command.  It is always used with another command, and makes no sense by itself.  It is ignored unless used with the --help parameter.

--help-mode parameter

• default choice: normal

• choice help-mode

  • brief

    • type: empty

    • This parameter specifies that brief documentation mode should be used.

  • normal

    • type: empty

    • This parameter specifies that normal documentation mode should be used.

  • full

    • type: empty

    • This parameter specifies that full documentation mode should be used.

3.9 --indent

The --indent parameter specifies the number of spaces that will be used to add to the indentation level, each time a child node is printed during program operation.

--indent parameter

3.10 --log

The --log parameter specifies the file name to be used for logging program messages, instead of STDOUT.  It can be used with the optional --log-append and --log-level parameters to control how the log file is written.

--log parameter

3.11 --log-append

The --log-append parameter specifies that the existing log file (if any) should be appended , instead of deleted.  It is ignored unless the --log parameter is present.

--log-append parameter

3.12 --log-level

The --log-level parameter controls the verbosity level of messages printed to the log file or STDOUT, if no log file is specified.

The log levels are incremental, meaning that each higher level includes everything from the previous level, plus additional messages.

There are 7 settings that can be used:

• none: All logging is suppressed.  Use with extreme caution!

• error: Error messages are printed, indicating problems that require attention.

• warn: Warning messages are printed, indicating problems that may require attention.

• info: Informational messages are printed, that indicate program status changes.

• debug: Debugging messages are printed that indicate program activity.

• debug2: Protocol debugging and trace messages are enabled.

• debug3: Very verbose debugging messages are enabled.  This has an impact on resources and performance, and should be used with caution.

log-level parameter

3.13 --modpath

The --modpath parameter specifies the YANG module search path to use while searching for YANG files.  It consists of a colon (':') separated list of path specifications, commonly found in Unix, such as the $PATH environment variable.

This parameter overrides the $YUMA_MODPATH environment variable, if it is present.

--modpath parameter

3.14 --new

The --new parameter specifies the YANG file or directory containing the new revision to be compared in the yangdiff program.

If this parameter indicates a filename, then it represents the YANG source module name to compare as the newer of the two revisions.

If this parameter indicates a directory (and the 'old' parameter indicates a filename), then it will be used to to search for a file with the same name as the 'new' parameter.

If the 'old' parameter identifies a directory as well (and the 'no-subdirs' parameter is present), then the modules within the 'new' directory will be  compared to files with the same name in the 'old' directory.  

If the --subdirs parameter is ''true'', then all sub-directories within the 'src' directory will also be checked.

If this string begins with a '~' character, then a username is expected to follow or a directory separator character.  If it begins with a '$' character, then an environment variable name is expected to follow.

~/some/path ==> <my-home-dir>/some/path

~fred/some/path ==> <fred-home-dir>/some/path

$workdir/some/path ==> <workdir-env-var>/some/path

This parameter must be present unless the --help  or --version parameters are present.

--new parameter

3.15 --old

The --old parameter specifies the YANG file or directory containing the older revision to be compared in the yangdiff program.

If this parameter indicates a filename, then it represents the YANG source module name to compare as the older of the two revisions.

If this parameter indicates a directory (and the 'old' parameter indicates a filename), then it will be used to to search for a file with the same name as the 'new' parameter.

If this string begins with a '~' character, then a username is expected to follow or a directory separator character.  If it begins with a '$' character, then an environment variable name is expected to follow.

~/some/path ==> <my-home-dir>/some/path

~fred/some/path ==> <fred-home-dir>/some/path

$workdir/some/path ==> <workdir-env-var>/some/path

This parameter must be present unless the --help  or --version parameters are present.

--old parameter

3.16 --output

The --output parameter specifies where the output files generated by the program will be stored.

• The default is STDOUT if this parameter is not specified and the --defnames parameter is set to 'false'.

• If this parameter represents an existing directory, then the --defnames parameter will be set to 'true' by default.

• If this parameter represents a file name, then the --defnames parameter will be ignored, and all translation output will be directed to the specified file.

• If this string begins with a '~' character, then a username is expected to follow or a directory separator character.   If it begins with a '$' character, then an environment variable name is expected to follow.

~/some/path ==> <my-home-dir>/some/path

~fred/some/path ==> <fred-home-dir>/some/path

$workdir/some/path ==> <workdir-env-var>/some/path

•  

• If the target specified in this parameter does not exist:

  • If there is only one file to be output, then this parameter is used as the file name.

  • If there are multiple files to be output, then this parameter is used as a directory name.  A new directory will be created, if it is needed.

• If the target specified in this parameter does exist:

  • If there is only one file to be output:

    • If the existing target is also a file, then the current file is over-written.

    • If the existing target is a directory, then the output file will be created in this directory.

  • If there are multiple files to be output:

    • If the existing target is a file, then an error will be generated instead of the output files.

    • If the existing target is a directory, then the output files will be created in the specified directory.

• Use a trailing path separator character to force this parameter value to be treated as a path specification (e.g., '~/workfiles/').

• This parameter is ignored if the --format parameter is missing.

--output parameter

3.17 --subdirs

The --subdirs parameter controls whether sub-directories should be searched or not, if they are found during a module search.

If false, the file search paths for modules, scripts, and data files will not include sub-directories if they exist in the specified path.

--subdirs parameter

3.18 --version

The --version parameter causes the program version string to be printed, and then the program will exit instead of running as normal.

All Yuma version strings use the same format:

<major>.<minor>.<yang-draft-version>.<svn-build-version>

An example version number that may be printed:

yangdiff  0.9.6.390

This indicates that the yangdump program version is '0.9', it supports YANG draft version '-06', and the subversion build identifier is '390'.

This parameter can be combined with the --help parameter.

--version parameter

3.19 --warn-idlen

The --warn-idlen parameter controls whether identifier length warnings will be generated.

The value zero disables all identifier length checking.  If non-zero, then a warning will be generated if an identifier is defined which has a length is greater than this amount.

--warn-idlen parameter

3.20 --warn-linelen

The --warn-linelen parameter controls whether line length warnings will be generated.

The value zero disables all line length checking.  If non-zero, then a warning will be generated if a YANG file line is entered which has a length is greater than this amount.

Tab characters are counted as 8 spaces.

--warn-linelen parameter

3.21 --warn-off

The --warn-off parameter suppresses a specific warning number.

The error and warning numbers, and the default messages, can be viewed with the yangdump program by using the --show-errors configuration parameter.

The specific warning message will be disabled for all modules.  No message will be printed and the warning will not count towards the total for that module.

--warn-off parameter

3.22 --yuma-home

The --yuma-home parameter specifies the project directory root to use when searching for files.

If present, this directory location will override the '$YUMA_HOME environment variable, if it is set.  If this parameter is set to a zero-length string, then the $YUMA_HOME environment variable will be ignored.

The following directories are searched when either the $YUMA_HOME environment variable or this parameter is set:

• $YUMA_HOME/modules

  • This sub-tree is searched for YANG files.

• $YUMA_HOME/data

  • This directory is searched for data files.

• $YUMA_HOME/scripts

  • This directory is searched for yangcli script files.

yuma-home parameter