[j-nsp] If there's anyone from Juniper on the list.....

[Phil Shafer]

Karsten Thomann via juniper-nsp writes:
>Who can get a message over to the Documentation group, it would
>be great if you could update the doc on the "insert" command to
>note that you have to create the object first, and then move it
>with the insert.
>
>May be common knowledge to old hands, but I'm still learning the
>ins and outs of JunOS. Looking at the doc, it seems that the order
>of operations would be this:
>
>edit firewall family inet filter foo
>insert term bar before term xyzzy
>error: statement 'bar' not found
>
>But it's actually this:
>
>edit firewall family inet filter foo
>set term bar from source-prefix-list source
>set term bar from destination-prefix-list dest
>set term bar from protocol tcp
>set term bar from destination-port ssh
>insert term bar before term xyzzy

This is fallout from the fact that "term bar" is a statement that
can't exist without contents.  Internally we call these "remove-empty"
and in the YANG terminology, they are called an equally-cryptic
"non-presence container".  But the results are the same: you can't have
an empty "term":

    [edit firewall filter foo]
    user at cli# set term bar
                            ^
    missing argument.
    
    [edit firewall filter foo]
    user at cli# set term bar ?
    Possible completions:
    + apply-groups         Groups from which to inherit configuration data
    + apply-groups-except  Don't inherit configuration data from these groups
      filter               Filter to include
    > from                 Define match criteria
    > then                 Action to take if the 'from' condition is matched
    [edit firewall filter foo]
    user at cli# set term bar

There must be something inside "term" for it to make any sense.
When you delete the last item under a "term", the "term" is removed
automatically.

In comparison, a non-remove-empty statement, like "ip-options"
does the "create on insert" behavior that you're after.

    [edit firewall filter foo term last]
    user at cli# insert from ip-options stream-id before route-record
    
    [edit firewall filter foo term last]
    user at cli# show
    from {
        ip-options [ stream-id route-record ];
    }

If we allowed "insert term new-term before term old-term", then
we'd make it and immediately remove it, which would be quite
annoying.  So we prevent the referencing of non-existent
remove-empty statements.

I'll pass all this along to the doc team so we can make it more
clear in the documentation.

Thanks,
 Phil