Re: [netmod] Action and RPC statements

[Lou Berger <[e-mail]>]

So i guess this comes down to D listed below.  While i was expecting C, i 
think D is probably workable. How would you envision the override would be 
expressed?

Lou


On November 6, 2017 9:49:49 AM Martin Bjorklund <[e-mail]> wrote:

> Lou Berger <[e-mail]> wrote:
>> Martin,
>>
>> If I have an RPC or action that changes state, how would the
>> persistence of that state be indicated with an NMBA data stores.  I
>> expected it to be related to the data store, but I read your mail
>> below as saying otherwise
>
> The side effects of executing an rpc or action is described in the
> rpc/action itself.  This is not a problem.  For example, see the
> definition of <edit-config>.  So with NMDA, this continues to work
> like before.
>
>
> /martin
>
>
>
>
>> Thanks,
>> Lou
>>
>>
>> On November 6, 2017 8:20:12 AM Martin Bjorklund <[e-mail]>
>> wrote:
>>
>> > Hi,
>> >
>> > Trying to summarize this issue.
>> >
>> > The problem is which datastore is used to:
>> >
>> >     1a. evaluate action ancestor nodes
>> >     1b. evaluate action input/output parameter leafref,
>> >         instance-identifier, must, when
>> >     2.  evaluate rpc input/output parameter leafref,
>> >         instance-identifier, must, when
>> >
>> > (Note that the side effects of an action/rpc is not part of this
>> > issue)
>> >
>> > I think it would be very weird if 1a and 1b were treated differently,
>> > so I just label them as 1 below.
>> >
>> > Possible solutions:
>> >
>> > A.  Always use <operational> for 1 and 2.
>> >
>> >     (This is what the current nmda draft says).
>> >
>> > B.  Let the client specify the datastore for 1, and use <operational>
>> >     for 2.
>> >
>> >     (Note that this is trivial in RESTCONF (since the datastore is
>> >     part of the URL), but would require a new parameter for NETCONF
>> >     (or a new <action2>).
>> >
>> > C.  Let the client specify the datastore for 1 and 2.
>> >
>> >     This would require a new generic parameter for how RPCs are
>> >     invoked in both NETCONF and RESTCONF.
>> >
>> > D.  Like B, but let the description of the "rpc" statement optionally
>> >     override this.
>> >
>> >
>> > I prefer B and then D.
>> >
>> >
>> > /martin
>> >
>> >
>> >
>> >
>> > Andy Bierman <[e-mail]> wrote:
>> >> On Thu, Nov 2, 2017 at 2:16 PM, Phil Shafer <[e-mail]> wrote:
>> >>
>> >> > Sorry, if I wasn't clear.  I meant the <datastore> element would
>> >> > be directly under <action>, so the system knows where to start
>> >> > looking for data.  Guessing is bad.
>> >> >
>> >> >
>> >> Totally agree guessing is bad.
>> >> Did you see the <action2> proposal in a previous email?
>> >> That is exactly what I proposed, except I do not want to
>> >> overload <action> so the new template would be a different name.
>> >>
>> >> I realize the expanded name of the datastore element prevents it from
>> >> being confused with top-level YANG nodes, but the conformance
>> >> is more clear with a new name.
>> >>
>> >>
>> >>
>> >>
>> >> > Thanks,
>> >> >  Phil
>> >> >
>> >>
>> >> Andy
>> >>
>> >>
>> >> >
>> >> >
>> >> > Andy Bierman writes:
>> >> > >So a server will be required to guess the correct datastore until it
>> >> > >finds the right one that matches the action instance?
>> >> > >
>> >> > >   <action>
>> >> > >       <top>
>> >> > >          <list1>
>> >> > >             <key>10</key>
>> >> > >             <do-test>
>> >> > >                <datastore>candidate</datastore>
>> >> > >             </do-test>
>> >> > >          </list1>
>> >> > >        </top>
>> >> > >    </action>
>> >> > >
>> >> > >The server will guess the datastore in some proprietary order and
>> >> > >parse
>> >> > >instances of /top/ and /top/list1.  Then it finds the <do-test> action
>> >> > >and parses the input to get to the datastore and find out the real
>> >> > datastore
>> >> > >to use.  If the server guessed wrong, then it reparses the <action>
>> >> > against
>> >> > >the requested datastore.  Hopefully the schema trees match up.
>> >> > >
>> >> > >Will vendors do all the extra work required to support this sort of
>> >> > >thing?
>> >> > >I doubt it.
>> >> > >
>> >> > >
>> >> > >Andy
>> >> > >
>> >> > >
>> >> > >
>> >> > >
>> >> > >On Tue, Oct 31, 2017 at 11:36 PM, Phil Shafer <[e-mail]>
>> >> > >wrote:
>> >> > >
>> >> > >> Robert Wilton writes:
>> >> > >> >ii) However, as far as I can see, it doesn't make sense for an action
>> >> > to
>> >> > >> >directly affect the contents of any configuration datastore, that
>> >> > should
>> >> > >> >be done via a purpose built rpc (like edit-config).
>> >> > >>
>> >> > >> An example action would be to retrieve the  fingerprint of an ssh
>> >> > >> key.  I might want to get the fingerprint of a key in <candidate>
>> >> > >> before I commit it.
>> >> > >>
>> >> > >> Or I could have an action that sets the SNMPv3 auth key to a random
>> >> > >> value, and I want to invoke that action against <candidate>.
>> >> > >>
>> >> > >> Seems like <startup> might also be an interesting place to target
>> >> > >> actions, but I can't think of a good example.
>> >> > >>
>> >> > >> There are always scenarios where something is useful, and the problem
>> >> > >> with ruling it out is that it becomes needed at some later point.
>> >> > >> We've a habit of ruling out things and later wishing we had them.
>> >> > >>
>> >> > >> Is the easy fix to just put a datastore leaf under rpc/action and
>> >> > >> have it default to operational?  Any specific RPC can define its
>> >> > >> own datastore leaf of hard-code the database in the description
>> >> > >> (explicitly or implicitly <operational>), but the <action> RPC only
>> >> > >> gets this if we make a new parameter for it.
>> >> > >>
>> >> > >> Thanks,
>> >> > >>  Phil
>> >> > >>
>> >> > >
>> >> > >--001a11411b0ad2d58d055cee96cb
>> >> > >Content-Type: text/html; charset="UTF-8"
>> >> > >Content-Transfer-Encoding: quoted-printable
>> >> > >
>> >> > ><div dir=3D"ltr">Hi,<div><br></div><div>So a server will be required
>> >> > >to
>> >> > gue=
>> >> > >ss the correct datastore until it</div><div>finds the right one that
>> >> > matche=
>> >> > >s the action instance?</div><div><br></div><div>=C2=A0
>> >> > =C2=A0&lt;action&gt;=
>> >> > ></div><div>=C2=A0 =C2=A0 =C2=A0 =C2=A0&lt;top&gt;</div><div>=C2=A0
>> >> > =C2=A0 =
>> >> > >=C2=A0 =C2=A0 =C2=A0 &lt;list1&gt;</div><div>=C2=A0 =C2=A0 =C2=A0
>> >> > >=C2=A0 =
>> >> > >=C2=A0 =C2=A0 =C2=A0&lt;key&gt;10&lt;/key&gt;</div><div>=C2=A0 =C2=A0
>> >> > =C2=
>> >> > >=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0&lt;do-test&gt;</div><div>=C2=A0 =C2=A0
>> >> > =C2=
>> >> > >=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 &lt;datastore&gt;candidate&lt;
>> >> > /datas=
>> >> > >tore&gt;</div><div>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0
>> >> > =C2=A0&lt;/do-=
>> >> > >test&gt;</div><div>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0
>> >> > &lt;/list1&gt;</div><=
>> >> > >div>=C2=A0 =C2=A0 =C2=A0 =C2=A0 &lt;/top&gt;</div><div>=C2=A0 =C2=A0
>> >> > &lt;/a=
>> >> > >ction&gt;</div><div><br></div><div>The server will guess the datastore
>> >> > in s=
>> >> > >ome proprietary order and parse</div><div>instances of /top/ and
>> >> > /top/list1=
>> >> > >.=C2=A0 Then it finds the &lt;do-test&gt; action</div><div>and parses
>> >> > >the
>> >> > i=
>> >> > >nput to get to the datastore and find out the real
>> >> > >datastore</div><div>to
>> >> > u=
>> >> > >se.=C2=A0 If the server guessed wrong, then it reparses the
>> >> > &lt;action&gt; =
>> >> > >against</div><div>the requested datastore.=C2=A0 Hopefully the schema
>> >> > trees=
>> >> > > match up.</div><div><br></div><div>Will vendors do all the extra work
>> >> > requ=
>> >> > >ired to support this sort of thing?</div><div>I doubt
>> >> > it.</div><div><br></d=
>> >> > >iv><div><br></div><div>Andy</div><div><br></div><div><br></
>> >> > div><div><br></d=
>> >> > >iv><div><div class=3D"gmail_extra"><br><div class=3D"gmail_quote">On
>> >> > >Tue,
>> >> > O=
>> >> > >ct 31, 2017 at 11:36 PM, Phil Shafer <span dir=3D"ltr">&lt;<a
>> >> > href=3D"mailt=
>> >> > >o:[e-mail]" target=3D"_blank">[e-mail]</a>&gt;</span>
>> >> > wrote=
>> >> > >:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0
>> >> > .8ex;border-le=
>> >> > >ft:1px #ccc solid;padding-left:1ex">Robert Wilton writes:<br>
>> >> > >&gt;ii) However, as far as I can see, it doesn&#39;t make sense for an
>> >> > acti=
>> >> > >on to<br>
>> >> > >&gt;directly affect the contents of any configuration datastore, that
>> >> > shoul=
>> >> > >d<br>
>> >> > >&gt;be done via a purpose built rpc (like edit-config).<br>
>> >> > ><br>
>> >> > >An example action would be to retrieve the=C2=A0 fingerprint of an
>> >> > >ssh<br>
>> >> > >key.=C2=A0 I might want to get the fingerprint of a key in
>> >> > &lt;candidate&gt=
>> >> > >;<br>
>> >> > >before I commit it.<br>
>> >> > ><br>
>> >> > >Or I could have an action that sets the SNMPv3 auth key to a
>> >> > >random<br>
>> >> > >value, and I want to invoke that action against &lt;candidate&gt;.<br>
>> >> > ><br>
>> >> > >Seems like &lt;startup&gt; might also be an interesting place to
>> >> > target<br>
>> >> > >actions, but I can&#39;t think of a good example.<br>
>> >> > ><br>
>> >> > >There are always scenarios where something is useful, and the
>> >> > >problem<br>
>> >> > >with ruling it out is that it becomes needed at some later point.<br>
>> >> > >We&#39;ve a habit of ruling out things and later wishing we had
>> >> > >them.<br>
>> >> > ><br>
>> >> > >Is the easy fix to just put a datastore leaf under rpc/action and<br>
>> >> > >have it default to operational?=C2=A0 Any specific RPC can define
>> >> > >its<br>
>> >> > >own datastore leaf of hard-code the database in the description<br>
>> >> > >(explicitly or implicitly &lt;operational&gt;), but the &lt;action&gt;
>> >> > RPC =
>> >> > >only<br>
>> >> > >gets this if we make a new parameter for it.<br>
>> >> > ><br>
>> >> > >Thanks,<br>
>> >> > >=C2=A0Phil<br>
>> >> > ></blockquote></div><br></div></div></div>
>> >> > >
>> >> > >--001a11411b0ad2d58d055cee96cb--
>> >> >
>> >
>> > _______________________________________________
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>> >
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>>
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