Re: edit-config operation

[Andy Bierman <ietf@andybierman.com>]

Vincent Cridlig wrote:

> Hi,
>
> edit-config is not clear to me, in particular the merge operation:
>
> "merge: The configuration data identified by the element
>  containing this attribute is merged with the configuration
>  at the corresponding level in the configuration datastore
>  identified by the target parameter.  This is the default
>  behavior."
>
> The draft says that the element must be merged in the config but it 
> does not explain how. Is there a clear definition of merge for XML 
> elements ?


merge is data-model specific.

> Also the given examples silently assume that the "name" element is a 
> selection key. It should be explicit in the draft.

There is absolutely no data model naming scheme defined in netconf.
I think these examples state that they are selecting by element called 
'name'.

> For example, let's imagine a data model where:
> - the root element is "foo"
> - foo must have a "name" child
> - foo may have zero to two "bar" elements
> - "bar" is a simpleType element
>
> Initial config:
> <foo>
>  <name>bla</name>
>  <bar>bar1</bar>
> </foo>
>
> Request:
> <foo xc:operation='merge'>
>  <name>bla</name>
>  <bar>bar2</bar>
> </foo>
>
> Possible outputs:
> <foo>
>  <name>bla</name>
>  <bar>bar2</bar>
> </foo>
>
> <foo>
>  <name>bla</name>
>  <bar>bar1</bar>
>  <bar>bar2</bar>
> </foo>
>
> Under merge meaning is implicitely a combination of replace or create 
> operation ?
> There is no clear separation between the selecting nodes and nodes 
> that must be updated.
> Even with replace operation we have the problem since we don't know 
> which bar must be replaced.
>
> Anybody implementing has the same problems ?


It is data model specific.
Do you have suggestions for changing it?

> Another thing: we are planning to implement a new edit-config with 
> xpath, as a new capability. It will look like that:
>
>       <edit-config>
>         <target>
>           <running/>
>         </target>
>         <config type="xpath" operation="replace" 
> sel="/netconf/security/rbac/users/user[name='Alice']">
>           <user>
>              <name>Alice</name>
>              <login>alicefoo</login>
>              <building>a2</building>
>              <room>100</room>
>           </user>
>         </config>
>       </edit-config>
>
> If the wg is interested to merge it to the standard xpath capability, 
> just request more details.
> We believe that edit-config should be extended with XPath in a similar 
> way than get-config.


You are using a nice clean XPath expression.
Unfortunately, this is a small subset of the entire language.
I think there are huge problems with setting or locking data items
based on arbitrary Xpath expressions.

> Sorry for the long mail.
> Thanks for your help.
> Vincent

Andy


--
to unsubscribe send a message to netconf-request@ops.ietf.org with
the word 'unsubscribe' in a single line as the message text body.
archive: <http://ops.ietf.org/lists/netconf/>