Request Change Indicators for Configuration Elements Using the Junos XML Protocol

A Junos XML protocol client application can use the <get-configuration> operation to request configuration data from a device running Junos OS or a device running Junos OS Evolved. A client application can request configuration data that includes indicators for configuration elements that have changed since the last commit operation. To request change indicators, the client application includes the changed="changed" attribute in the <get-configuration> tag.

The returned configuration includes the junos:changed="changed" attribute for changed elements. The device determines which elements to mark as changed depending on the configuration source. You specify the source by including the database attribute in the <get-configuration> tag. The default is candidate, which retrieves the candidate configuration. The options include:

• database="candidate"—(Default) The device compares the candidate configuration to the active configuration. The configuration includes the junos:changed="changed" attribute for elements that were added to the candidate configuration after the last commit operation.

• database="committed"—The device compares the active configuration to the first rollback configuration. The configuration includes the junos:changed="changed" attribute for elements that were added to the active configuration by the most recent commit.

The server indicates which elements have changed by including the junos:changed="changed" attribute in the opening tag of every parent tag element in the path to the changed configuration element. If the changed configuration element is a single (empty) tag, the tag displays the junos:changed="changed" attribute. If the changed element is a container element, the configuration displays the junos:changed="changed" attribute in the opening container tag and also in the opening tag for each child tag element enclosed in the container element.

The Junos XML protocol server encloses its response in <rpc-reply> and <configuration> elements.

If the requested output format is JSON, the server includes the "junos:changed" : "changed" attribute in the attribute lists for the same elements as described previously.

Note:

When a commit operation succeeds, the Junos XML protocol server removes the junos:changed="changed" attribute from all tag elements. However, if the commit generates warnings, the attribute remains. In this case, the junos:changed="changed" attribute appears on tag elements that changed before the commit as well as on tag elements that changed after the commit.

An example of a commit-time warning is the message explaining that a configuration element does not apply until you reboot the device. The Junos XML protocol server returns the warning in an <xnm:error> element when it confirms the success of the commit operation.

To remove the junos:changed="changed" attribute from elements that changed before the commit, the client application must take the necessary actions to eliminate the cause of the warning, and then commit the configuration again.

You can combine the changed attribute with one or more of the following attributes in the <get-configuration> tag:

• database

• inherit and optionally groups and interface-ranges

• junos:key

The junos:changed="changed" attribute appears only in Junos XML output (the default) and JSON output. Thus, you cannot combine the changed attribute with the format="text" attribute or with the compare attribute, which produces only text output.

When you include the commit-scripts="view" attribute, the junos:changed="changed" attribute is automatically included in the output. Thus, you do not need to explicitly include the changed="changed" attribute in the <get-configuration> request.

The following example requests change indicators for configuration elements at the [edit system syslog] hierarchy level in the candidate configuration. The output indicates that a log file called interactive-commands has been configured since the last commit.