Clixon configuration files are XML files modeled by YANG. By default, the main config file is installed in /usr/local/etc/clixon.xml, but can be changed by the -f <file> command-line option.

The YANG specification for Clixon configuration is clixon-config.yang. This configuration file is updated regularly.

Normally, all Clixon processes (backend, cli, netconf, restconf) use the same configuration, although some options are not valid for all processes.

Please consult the YANG spec directly if you want detailed description of config options.


The following is the configuration file of an example:

<clixon-config xmlns="">

The option CLICON_CONFIGFILE is special, it must be available before the configuration file is found (see Loading the configuration), which means that the value in the file is a no-op.

The restconf clause defines RESTCONF configuration options as described in the RESTCONF section.

Loading the configuration

There are several ways to manage how Clixon finds its configuration files, in priority order:

  1. Start a clixon program with the -f <FILE> option. For example:

    clixon_backend -f FILE
  2. At install time, Use the --with-configfile=FILE option to configure a default location:

    ./configure -f FILE
  3. At install time: ./configure --with-sysconfig=<dir> when configuring. Then FILE is <dir>/clixon.xml

  4. At install time: ./configure --sysconfig=<dir> when configuring. Then FILE is <dir>/etc/clixon.xml

  5. If none of the above: FILE is /usr/local/etc/clixon.xml

The following options control the Clixon configuration:

The configure file itself. Due to bootstrapping reasons, its value is meaningless in a file but can be useful for documentation purposes.

A directory of extra configuration files loaded after the main configuration. It can alsp be specified using the -E <dir> command-line option. These extra configuration files are read in alphabetical order after the main configuration as follows:

  • leaf values are overwritten
  • leaf-list values are appended

Runtime modification

You can modify clixon options at runtime by using the -o option to modify the configuration specified in the configuration file. For example, add usr/local/share/ietf to the list of directories where yang files are searched for:

clixon_cli -o CLICON_YANG_DIR=/usr/local/share/ietf


CLICON_FEATURE is a list of values, describing how Clixon supports feature.

A value is specified as one of the following:

  • <module>:<feature> : enable a specific feature in a specific module
  • *:* : enable all features in all modules
  • <module>:* : enable all features in the specified module
  • *:<feature> : enable the specific feature in all modules.



Supplying the -o option adds a value to the feature list.

Clixon have three hardcoded features:

  • ietf-netconf:candidate (RFC6241 8.3)
  • ietf-netconf:validate (RFC6241 8.6)
  • ietf-netconf:xpath (RFC6241 8.9)

Finding YANG files

The example have two options for finding Yang files:


which means that Yang files are searched for in /usr/local/share/clixon and that module clixon-hello is loaded. Note:

  • clixon-hello.yang must be present in /usr/local/share/clixon
  • Clixon itself may load several YANG files as part of the system startup, such as clixon-config.yang. These must all reside in the list of CLICON_YANG_DIR:s.
  • When a Yang file is loaded, it may contain references to other Yang files (eg using import and include). They must also be found in the list of CLICON_YANG_DIR:s.

The following configuration file options control the loading of Yang files:

A list of directories (yang dir path) where Clixon searches for module and submodules.
Load a specific Yang module given by a file.
Specifies a single module to load. The module is searched for in the yang dir path.
Specifies a revision to the main module.
Load all yang modules in this directory.

Note that the special YANG_INSTALLDIR autoconf configure option, by default /usr/local/share/clixon should be included in the yang dir path for Clixon system files to be found.

You can combine the options, however, if there are different variants of the same module, more specific options override less specific. The precedence of the options are as follows:


Note that using CLICON_YANG_MAIN_DIR Clixon may find several files containing the same Yang module. Clixon will prefer the one without a revision date if such a file exists. If no file has a revision date, Clixon will prefer the newest.

Default values

CLICON_YANG_REGEXP which is not present in the hello world is an example of a configuration option with a default value of posix: