Replace Only Updated Elements in Configuration Data Using the Junos XML Protocol
In a Junos XML protocol session with a device running Junos OS, to replace configuration
elements (hierarchy levels and configuration objects) only if they differ between
the loaded configuration and the existing configuration, the application emits the
<load-configuration> tag element with the
action="update" attribute in an <rpc>
tag
element.
<rpc>
<!-- For a file -->
<load-configuration action="update" url="file" [format="format"]/>
<!-- For a data stream -->
<load-configuration action="update" [format="format"]>
<!-- configuration data -->
</load-configuration>
</rpc>For
more information about the url and format
attributes, see Uploading and Formatting Configuration Data in a Junos XML Protocol
Session.
Starting in Junos OS Release 21.1R1, the ephemeral configuration database
supports the action="update" attribute on supported
platforms.
This operation is equivalent to the Junos OS CLI load update
configuration mode command. The Junos OS configuration management software compares
the two complete configurations. Each configuration element that is different in the
loaded configuration replaces its corresponding element in the existing
configuration. Elements that are the same in both configurations remain unchanged.
When the configuration is later committed, only system processes that are affected
by the changed configuration elements parse the new configuration.
To
represent the replacement elements, the application uses the same syntax as for new
elements, as described in Creating New Elements in Configuration Data Using the Junos XML
Protocol. In the following Junos XML and JSON representations of the
configuration, the object identifier is called name.
Junos XML elements:
<configuration>
<!-- opening tag for each parent of the element -->
<container-tag>
<name>identifier</name>
<!-- tag elements for other children, if any -->
</container-tag>
<!-- closing tag for each parent of the element -->
</configuration>ASCII text:
<configuration-text>
/* statements for parent levels of the element */
element identifier {
/* child statements if any */
}
/* closing braces for parent levels of the element */
</configuration-text>
JSON:
<configuration-json>
{
"configuration" : {
/* JSON objects for parent levels of the element */
"container-tag" : {
"object" : [
{
"name" : "identifier",
"statement-name" : "statement-value", # if any
/* additional data and child objects */ # if any
}
],
/* data and child objects */ # if any
}
/* closing braces for parent levels of the element */
}
}
</configuration-json>You can load configuration data formatted using JavaScript Object Notation (JSON) starting in Junos OS Release 16.1.
The following example shows how to update the candidate configuration with the
contents of the file /tmp/new.conf (which resides on the
device). The file contains a complete configuration represented as Junos XML tag
elements (the default), so the format attribute is
omitted.
