Understanding the Junos DDL Extensions YANG Module
The Junos Data Definition Language (DDL) extensions YANG module contains YANG extensions for Junos devices. These extensions include statements that can define constraints on configuration data and the valid values for strings. There are also statements that you include in custom RPCs to define a CLI command for the RPC and to specify details about the action script to invoke when the RPC is executed. In addition, there are statements that you can use to define helper action scripts for individual command options and configuration statements, for example, to display a list of acceptable values for options or statements.
Starting in Junos OS Release 17.4, Junos OS YANG modules use a new naming convention for the module’s name, filename, and namespace. The module’s name and filename include the device family and Junos OS release, and the filename also includes a revision date.
Table 1 outlines the statements in the DDL extensions module and provides a brief description of each statement.
Statement Keyword |
Argument Description |
---|---|
|
Define the actions taken when you execute a custom RPC.
Use the Starting in Junos OS Release 17.3, the |
|
Define the script that calculates and displays the possible values for a given command option or configuration statement in a custom YANG data model when a user requests context-sensitive help in the CLI. Use the |
|
String defining the operational command that is used to execute the corresponding RPC in the Junos OS CLI. Starting in Junos OS Release 17.3, the |
|
String that identifies a constraint on the configuration data. Whereas the argument for the YANG |
|
String that defines the warning message that is emitted
when the constraint defined by the corresponding |
|
String that defines the error message emitted when the
constraint defined by the corresponding |
|
Restrict the values accepted for nodes of type string to those that match the POSIX regular expression defined in this string. |
|
String specifying the name of an action script. This
is a substatement of the |