Automation

I'm having some difficulty processing Junos XML with the lxml module with Python.  Much of the difficulty lies with the namespace that appends a URI to the tag names.  With 'find' at least there is a fairly easy workaround with {*}, such as:

root.find('{*}chassis')

but attempting to use xpath expressions to pull out elemts has not worked at all so far for me.  I noticed that the PyEZ modulse makes use of lxml, so I was wondering if there was anyone with experience using that module to process junos xml.

Hi,

Hopefully the following might help to demonstrate.

In this example the entire configuration has been retrieved from the device, and using the xpath() method just a subset of that data has been output (part of the global address-book in this scenario).

from jnpr.junos import Device
from lxml import etree
dev = Device(host='x.x.x.x', user='foo', passwd='bar')
dev.open()
data = dev.rpc.get_config()
output = data.xpath('/rpc-reply/configuration/security/address-book[name="global"]/address[name="MySlashTwenty"]')
print etree.tostring(output[0])

An alternate approach could also be to only retrieve a subset of the data from the device instead of everything,

from jnpr.junos import Device
from lxml import etree
from lxml.builder import E
dev = Device(host='x.x.x.x', user='foo', passwd='bar')
dev.open()
filter = E('security', E('address-book', E('name', 'global'), E('address', E('name','GoogleDNS'))))
data = dev.rpc.get_config(filter)
output = data.xpath('/rpc-reply/configuration')
print etree.tostring(output[0])

The results produced for each scenario are as shown below:

Example 1:
<address>
                <name>MySlashTwenty</name>
                <ip-prefix>10.142.96.0/20</ip-prefix>
</address>
 

Example 2:
<configuration changed-seconds="1453826277" changed-localtime="2016-01-26 16:37:57 UTC">
    <security>
        <address-book>
            <name>global</name>
            <address>
                <name>GoogleDNS</name>
                <ip-prefix>4.4.4.4/32</ip-prefix>
            </address>
        </address-book>
    </security>
</configuration>

I have to admit, that I normally develop scripts in SLAX and my Python is far from great, and there could of course be better ways to perform this...

Regards,

Andy

Thanks asharp, I'm not quite sure why, but it does seem if you get the entire config the namespace issue isn't as much of a concern, maybe something to do with the sub elements not needing the namespace attached.