subject:"\[Freeipa\-devel\] Please review\: V4\/AD user short names design draft"

On 03/01/2017 05:28 PM, Alexander Bokovoy wrote:

On ke, 01 maalis 2017, Simo Sorce wrote:

> My take is: cut API/UI work, and do the underlying infrastructure work
> for the widest set of serves/clients possible instead.
>
> It is much more important to get the underlying gears done than to add
> UI candy, that can be delayed.
>
> Simo.
>

I agree, we just have to come to agreement of *which* gears are really
necessary.

Indeed, but adding attributes to ipaConfig and the ID Views is not hard,
it is a matter of extending two objectclasses instead of one ... if we
decide that Id Views are a good abstraction point.

Adding the same attribute to ID View and to ipaConfig sounds logical to
me.

Martin, if you want help with this, I can implement ID View-related
parts. SSSD does have code to retrieve ipaConfig already, and it also
has support for reading ID View associated with the host. The resulting
value wouldn't end up in the same place, though, but this is something
to handle on SSSD side.

I was thinking about this at night (insomnia FTW) and it is actually 
pretty easy to extend ID view with the same attribute (see my other 
reply to Simo). Given the UI will be pretty dumb, we just can add the 
new attribute to the ID view object and a common code will be 
responsible for validation of changed values.

--
Martin^3 Babinsky

--
Manage your subscription for the Freeipa-devel mailing list:
https://www.redhat.com/mailman/listinfo/freeipa-devel
Contribute to FreeIPA: http://www.freeipa.org/page/Contribute/Code

Re: [Freeipa-devel] Please review: V4/AD user short names design draft


On 03/01/2017 05:51 PM, Simo Sorce wrote:

On Wed, 2017-03-01 at 17:29 +0100, Martin Basti wrote:


On 01.03.2017 17:04, Simo Sorce wrote:

On Wed, 2017-03-01 at 16:47 +0100, Martin Babinsky wrote:

On 03/01/2017 04:32 PM, Simo Sorce wrote:

On Wed, 2017-03-01 at 16:17 +0100, Martin Babinsky wrote:

On 03/01/2017 03:42 PM, Simo Sorce wrote:

On Tue, 2017-02-28 at 13:29 +0100, Martin Babinsky wrote:

Hello list,

I have put together a draft of design page describing server-side
implementation of user short name -> fully-qualified name resolution.[1]

In the end I have taken the liberty to change a few aspects of the
design we have agreed on before and I will be grad if we can discuss
them further.

Me and Honza have discussed the object that should hold the domain
resolution order and given the fact that IPA domain can also be a part
of this list, we have decided that this information is no longer bound
to trust configuration and should be a part of the global config instead.

Also we have purposefully cut down the API only to a raw manipulation of
the attribute using an option of `ipa config-mod`. The reasons for this
are twofold:

* the developer resources are quite scarce and it may be good to
follow YAGNI[2] principle to implement the dumbest API now and not to
invest into more high-level interface unless there is a demand for it

* we can imagine that the manipulation of the domain resolution order
is a rare operation (ideally only once all trusts are established), so I
am not convinced that it is worth investing into designing higher-level API

I propose we first develop the "dumber" parts first to unblock the SSSD
part. If we have spare cycle afterwards then we can design and implement
more bells-and-whistles afterwards.

[1] https://www.freeipa.org/page/V4/AD_User_Short_Names
[2] https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it

Thank you Martin,
this is a good initial proposal.

I have a few issues with this design:
- It conflates the idea of ordering with the idea of shortening user
names

I fail to see where the conflation takes place. The ordered list is
stored on the server. The client then uses it to expand short names. I
guess I am just missing something.

The attribute is called ipaNTDomainResolutionOrder, nothing in that
attribute says anything about making names become short names.
If it were ipaNTShortNameDomainResolutionOrder then it would be
specific, as it is it seem just to refer to the order in which domain
are resolved, but that is somethign we want in order to determine which
domains SSSD is going to make use short names too, not just the order in
which domains are resolved.
I hope this makes it clearer.


- It allows only for one setting for all the machines, no way to treat
different groups of machines differently


Yes it was discussed that the setting will be global. I would implement
local overrides only when there is a demand for the feature given
development time is short.

Demand is immediate, and it is obvious IMO.


Such demand was not made clear during previous discussions and was not
mentioned by SSSD guys either AFAIK.

I guess this is why we do reviews :-)


The first one is probably just a matter of using a more specific name
for the new attribute, or, perhaps not use a new attribute at all but
just use ipaConfigString with an agreed syntax like:
ipaConfigString: Domains Use Short Name List: aaa bbb ccc ddd

The side effect of using ipaConfigString is that we can set this on
older servers too, so people do not have to upgrade their servers to use
this. Old servers will not have any validation, but that is ok, sssd
must be prepared to receive a bad list and deal with it appropriately
anyway.


No more 'ipaConfigString' attribute values, please. Me and everyone else
fixing e.g. replication issues can relate to the pain of doing CRUD
operations involving them.

ipaConfigString was devised explicitly so that configuration options
could be added without replication issues because the string can be
accepted by any server version.
So what replication issues are there ?
What has CRUD to do with it ?


Well consider client doing a) retrieve ipaDomainResolutionOrder and
split it by delimiter, or b) retrieve values of ipaConfigString, iterate
until you find one that starts with "Domains Use Short Name list:",
strip off the rest of the value and split it by delimiter.

I do not see any problem with this.

I disagree,

ipaConfigString evokes that this is IPA configuration, but AFAIK the
SSSD is the consumer of data and it is unrelated to configuration of IPA
server. If you plan to extend usage of 'ipaDomainResolutionOrder' to
more entries than one, then is better to have separate attribute that
allows better LDAP searches (debugging, support).
Why SSSD instead of downloading the exact attribute content should do a
parsing of messy values that can be inside ipaConfigString?

Why we suddenly plan to support older servers with a new feature? In
past access to new

Re: [Freeipa-devel] Please review: V4/AD user short names design draft

On Wed, 2017-03-01 at 17:29 +0100, Martin Basti wrote:
> 
> On 01.03.2017 17:04, Simo Sorce wrote:
> > On Wed, 2017-03-01 at 16:47 +0100, Martin Babinsky wrote:
> >> On 03/01/2017 04:32 PM, Simo Sorce wrote:
> >>> On Wed, 2017-03-01 at 16:17 +0100, Martin Babinsky wrote:
>  On 03/01/2017 03:42 PM, Simo Sorce wrote:
> > On Tue, 2017-02-28 at 13:29 +0100, Martin Babinsky wrote:
> >> Hello list,
> >>
> >> I have put together a draft of design page describing server-side
> >> implementation of user short name -> fully-qualified name 
> >> resolution.[1]
> >>
> >> In the end I have taken the liberty to change a few aspects of the
> >> design we have agreed on before and I will be grad if we can discuss
> >> them further.
> >>
> >> Me and Honza have discussed the object that should hold the domain
> >> resolution order and given the fact that IPA domain can also be a part
> >> of this list, we have decided that this information is no longer bound
> >> to trust configuration and should be a part of the global config 
> >> instead.
> >>
> >> Also we have purposefully cut down the API only to a raw manipulation 
> >> of
> >> the attribute using an option of `ipa config-mod`. The reasons for this
> >> are twofold:
> >>
> >> * the developer resources are quite scarce and it may be good to
> >> follow YAGNI[2] principle to implement the dumbest API now and not to
> >> invest into more high-level interface unless there is a demand for it
> >>
> >> * we can imagine that the manipulation of the domain resolution 
> >> order
> >> is a rare operation (ideally only once all trusts are established), so 
> >> I
> >> am not convinced that it is worth investing into designing 
> >> higher-level API
> >>
> >> I propose we first develop the "dumber" parts first to unblock the SSSD
> >> part. If we have spare cycle afterwards then we can design and 
> >> implement
> >> more bells-and-whistles afterwards.
> >>
> >> [1] https://www.freeipa.org/page/V4/AD_User_Short_Names
> >> [2] https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it
> > Thank you Martin,
> > this is a good initial proposal.
> >
> > I have a few issues with this design:
> > - It conflates the idea of ordering with the idea of shortening user
> > names
>  I fail to see where the conflation takes place. The ordered list is
>  stored on the server. The client then uses it to expand short names. I
>  guess I am just missing something.
> >>> The attribute is called ipaNTDomainResolutionOrder, nothing in that
> >>> attribute says anything about making names become short names.
> >>> If it were ipaNTShortNameDomainResolutionOrder then it would be
> >>> specific, as it is it seem just to refer to the order in which domain
> >>> are resolved, but that is somethign we want in order to determine which
> >>> domains SSSD is going to make use short names too, not just the order in
> >>> which domains are resolved.
> >>> I hope this makes it clearer.
> >>>
> > - It allows only for one setting for all the machines, no way to treat
> > different groups of machines differently
> >
>  Yes it was discussed that the setting will be global. I would implement
>  local overrides only when there is a demand for the feature given
>  development time is short.
> >>> Demand is immediate, and it is obvious IMO.
> >>>
> >> Such demand was not made clear during previous discussions and was not
> >> mentioned by SSSD guys either AFAIK.
> > I guess this is why we do reviews :-)
> >
> > The first one is probably just a matter of using a more specific name
> > for the new attribute, or, perhaps not use a new attribute at all but
> > just use ipaConfigString with an agreed syntax like:
> > ipaConfigString: Domains Use Short Name List: aaa bbb ccc ddd
> >
> > The side effect of using ipaConfigString is that we can set this on
> > older servers too, so people do not have to upgrade their servers to use
> > this. Old servers will not have any validation, but that is ok, sssd
> > must be prepared to receive a bad list and deal with it appropriately
> > anyway.
> >
>  No more 'ipaConfigString' attribute values, please. Me and everyone else
>  fixing e.g. replication issues can relate to the pain of doing CRUD
>  operations involving them.
> >>> ipaConfigString was devised explicitly so that configuration options
> >>> could be added without replication issues because the string can be
> >>> accepted by any server version.
> >>> So what replication issues are there ?
> >>> What has CRUD to do with it ?
> >>>
> >> Well consider client doing a) retrieve ipaDomainResolutionOrder and
> >> split it by delimiter, or b) retrieve values of ipaConfigString, iterate
> >> until you find one that starts with "Domains Use Short Name

Re: [Freeipa-devel] Please review: V4/AD user short names design draft

2017-03-01 Thread Martin Basti




On 01.03.2017 17:04, Simo Sorce wrote:

On Wed, 2017-03-01 at 16:47 +0100, Martin Babinsky wrote:

On 03/01/2017 04:32 PM, Simo Sorce wrote:

On Wed, 2017-03-01 at 16:17 +0100, Martin Babinsky wrote:

On 03/01/2017 03:42 PM, Simo Sorce wrote:

On Tue, 2017-02-28 at 13:29 +0100, Martin Babinsky wrote:

Hello list,

I have put together a draft of design page describing server-side
implementation of user short name -> fully-qualified name resolution.[1]

In the end I have taken the liberty to change a few aspects of the
design we have agreed on before and I will be grad if we can discuss
them further.

Me and Honza have discussed the object that should hold the domain
resolution order and given the fact that IPA domain can also be a part
of this list, we have decided that this information is no longer bound
to trust configuration and should be a part of the global config instead.

Also we have purposefully cut down the API only to a raw manipulation of
the attribute using an option of `ipa config-mod`. The reasons for this
are twofold:

* the developer resources are quite scarce and it may be good to
follow YAGNI[2] principle to implement the dumbest API now and not to
invest into more high-level interface unless there is a demand for it

* we can imagine that the manipulation of the domain resolution order
is a rare operation (ideally only once all trusts are established), so I
am not convinced that it is worth investing into designing higher-level API

I propose we first develop the "dumber" parts first to unblock the SSSD
part. If we have spare cycle afterwards then we can design and implement
more bells-and-whistles afterwards.

[1] https://www.freeipa.org/page/V4/AD_User_Short_Names
[2] https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it

Thank you Martin,
this is a good initial proposal.

I have a few issues with this design:
- It conflates the idea of ordering with the idea of shortening user
names

I fail to see where the conflation takes place. The ordered list is
stored on the server. The client then uses it to expand short names. I
guess I am just missing something.

The attribute is called ipaNTDomainResolutionOrder, nothing in that
attribute says anything about making names become short names.
If it were ipaNTShortNameDomainResolutionOrder then it would be
specific, as it is it seem just to refer to the order in which domain
are resolved, but that is somethign we want in order to determine which
domains SSSD is going to make use short names too, not just the order in
which domains are resolved.
I hope this makes it clearer.


- It allows only for one setting for all the machines, no way to treat
different groups of machines differently


Yes it was discussed that the setting will be global. I would implement
local overrides only when there is a demand for the feature given
development time is short.

Demand is immediate, and it is obvious IMO.


Such demand was not made clear during previous discussions and was not
mentioned by SSSD guys either AFAIK.

I guess this is why we do reviews :-)


The first one is probably just a matter of using a more specific name
for the new attribute, or, perhaps not use a new attribute at all but
just use ipaConfigString with an agreed syntax like:
ipaConfigString: Domains Use Short Name List: aaa bbb ccc ddd

The side effect of using ipaConfigString is that we can set this on
older servers too, so people do not have to upgrade their servers to use
this. Old servers will not have any validation, but that is ok, sssd
must be prepared to receive a bad list and deal with it appropriately
anyway.


No more 'ipaConfigString' attribute values, please. Me and everyone else
fixing e.g. replication issues can relate to the pain of doing CRUD
operations involving them.

ipaConfigString was devised explicitly so that configuration options
could be added without replication issues because the string can be
accepted by any server version.
So what replication issues are there ?
What has CRUD to do with it ?


Well consider client doing a) retrieve ipaDomainResolutionOrder and
split it by delimiter, or b) retrieve values of ipaConfigString, iterate
until you find one that starts with "Domains Use Short Name list:",
strip off the rest of the value and split it by delimiter.

I do not see any problem with this.

I disagree,

ipaConfigString evokes that this is IPA configuration, but AFAIK the 
SSSD is the consumer of data and it is unrelated to configuration of IPA 
server. If you plan to extend usage of 'ipaDomainResolutionOrder' to 
more entries than one, then is better to have separate attribute that 
allows better LDAP searches (debugging, support).
Why SSSD instead of downloading the exact attribute content should do a 
parsing of messy values that can be inside ipaConfigString?


Why we suddenly plan to support older servers with a new feature? In 
past access to new features required to upgrade freeipa, why we should 
increase complexity of code and ldap

Re: [Freeipa-devel] Please review: V4/AD user short names design draft

On ke, 01 maalis 2017, Simo Sorce wrote:

> My take is: cut API/UI work, and do the underlying infrastructure work
> for the widest set of serves/clients possible instead.
>
> It is much more important to get the underlying gears done than to add
> UI candy, that can be delayed.
>
> Simo.
>

I agree, we just have to come to agreement of *which* gears are really
necessary.

Indeed, but adding attributes to ipaConfig and the ID Views is not hard,
it is a matter of extending two objectclasses instead of one ... if we
decide that Id Views are a good abstraction point.

Adding the same attribute to ID View and to ipaConfig sounds logical to
me.

Martin, if you want help with this, I can implement ID View-related
parts. SSSD does have code to retrieve ipaConfig already, and it also
has support for reading ID View associated with the host. The resulting
value wouldn't end up in the same place, though, but this is something
to handle on SSSD side.

--
/ Alexander Bokovoy

--
Manage your subscription for the Freeipa-devel mailing list:
https://www.redhat.com/mailman/listinfo/freeipa-devel
Contribute to FreeIPA: http://www.freeipa.org/page/Contribute/Code

Re: [Freeipa-devel] Please review: V4/AD user short names design draft

On Wed, 2017-03-01 at 16:47 +0100, Martin Babinsky wrote:
> On 03/01/2017 04:32 PM, Simo Sorce wrote:
> > On Wed, 2017-03-01 at 16:17 +0100, Martin Babinsky wrote:
> >> On 03/01/2017 03:42 PM, Simo Sorce wrote:
> >>> On Tue, 2017-02-28 at 13:29 +0100, Martin Babinsky wrote:
>  Hello list,
> 
>  I have put together a draft of design page describing server-side
>  implementation of user short name -> fully-qualified name resolution.[1]
> 
>  In the end I have taken the liberty to change a few aspects of the
>  design we have agreed on before and I will be grad if we can discuss
>  them further.
> 
>  Me and Honza have discussed the object that should hold the domain
>  resolution order and given the fact that IPA domain can also be a part
>  of this list, we have decided that this information is no longer bound
>  to trust configuration and should be a part of the global config instead.
> 
>  Also we have purposefully cut down the API only to a raw manipulation of
>  the attribute using an option of `ipa config-mod`. The reasons for this
>  are twofold:
> 
> * the developer resources are quite scarce and it may be good to
>  follow YAGNI[2] principle to implement the dumbest API now and not to
>  invest into more high-level interface unless there is a demand for it
> 
> * we can imagine that the manipulation of the domain resolution order
>  is a rare operation (ideally only once all trusts are established), so I
>  am not convinced that it is worth investing into designing higher-level 
>  API
> 
>  I propose we first develop the "dumber" parts first to unblock the SSSD
>  part. If we have spare cycle afterwards then we can design and implement
>  more bells-and-whistles afterwards.
> 
>  [1] https://www.freeipa.org/page/V4/AD_User_Short_Names
>  [2] https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it
> >>>
> >>> Thank you Martin,
> >>> this is a good initial proposal.
> >>>
> >>> I have a few issues with this design:
> >>> - It conflates the idea of ordering with the idea of shortening user
> >>> names
> >>
> >> I fail to see where the conflation takes place. The ordered list is
> >> stored on the server. The client then uses it to expand short names. I
> >> guess I am just missing something.
> >
> > The attribute is called ipaNTDomainResolutionOrder, nothing in that
> > attribute says anything about making names become short names.
> > If it were ipaNTShortNameDomainResolutionOrder then it would be
> > specific, as it is it seem just to refer to the order in which domain
> > are resolved, but that is somethign we want in order to determine which
> > domains SSSD is going to make use short names too, not just the order in
> > which domains are resolved.
> > I hope this makes it clearer.
> >
> >>> - It allows only for one setting for all the machines, no way to treat
> >>> different groups of machines differently
> >>>
> >>
> >> Yes it was discussed that the setting will be global. I would implement
> >> local overrides only when there is a demand for the feature given
> >> development time is short.
> >
> > Demand is immediate, and it is obvious IMO.
> >
> 
> Such demand was not made clear during previous discussions and was not 
> mentioned by SSSD guys either AFAIK.

I guess this is why we do reviews :-)

> >>> The first one is probably just a matter of using a more specific name
> >>> for the new attribute, or, perhaps not use a new attribute at all but
> >>> just use ipaConfigString with an agreed syntax like:
> >>> ipaConfigString: Domains Use Short Name List: aaa bbb ccc ddd
> >>>
> >>> The side effect of using ipaConfigString is that we can set this on
> >>> older servers too, so people do not have to upgrade their servers to use
> >>> this. Old servers will not have any validation, but that is ok, sssd
> >>> must be prepared to receive a bad list and deal with it appropriately
> >>> anyway.
> >>>
> >>
> >> No more 'ipaConfigString' attribute values, please. Me and everyone else
> >> fixing e.g. replication issues can relate to the pain of doing CRUD
> >> operations involving them.
> >
> > ipaConfigString was devised explicitly so that configuration options
> > could be added without replication issues because the string can be
> > accepted by any server version.
> > So what replication issues are there ?
> > What has CRUD to do with it ?
> >
> 
> Well consider client doing a) retrieve ipaDomainResolutionOrder and 
> split it by delimiter, or b) retrieve values of ipaConfigString, iterate 
> until you find one that starts with "Domains Use Short Name list:", 
> strip off the rest of the value and split it by delimiter.

I do not see any problem with this.

> I just feel anything involving 'ipaConfigString' leads to design smell, 
> sorry. Yes it is my personal opinion but I think there are more people 
> sharing it. If not, I am happy to hear

Re: [Freeipa-devel] Please review: V4/AD user short names design draft


On 03/01/2017 04:32 PM, Simo Sorce wrote:

On Wed, 2017-03-01 at 16:17 +0100, Martin Babinsky wrote:

On 03/01/2017 03:42 PM, Simo Sorce wrote:

On Tue, 2017-02-28 at 13:29 +0100, Martin Babinsky wrote:

Hello list,

I have put together a draft of design page describing server-side
implementation of user short name -> fully-qualified name resolution.[1]

In the end I have taken the liberty to change a few aspects of the
design we have agreed on before and I will be grad if we can discuss
them further.

Me and Honza have discussed the object that should hold the domain
resolution order and given the fact that IPA domain can also be a part
of this list, we have decided that this information is no longer bound
to trust configuration and should be a part of the global config instead.

Also we have purposefully cut down the API only to a raw manipulation of
the attribute using an option of `ipa config-mod`. The reasons for this
are twofold:

   * the developer resources are quite scarce and it may be good to
follow YAGNI[2] principle to implement the dumbest API now and not to
invest into more high-level interface unless there is a demand for it

   * we can imagine that the manipulation of the domain resolution order
is a rare operation (ideally only once all trusts are established), so I
am not convinced that it is worth investing into designing higher-level API

I propose we first develop the "dumber" parts first to unblock the SSSD
part. If we have spare cycle afterwards then we can design and implement
more bells-and-whistles afterwards.

[1] https://www.freeipa.org/page/V4/AD_User_Short_Names
[2] https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it


Thank you Martin,
this is a good initial proposal.

I have a few issues with this design:
- It conflates the idea of ordering with the idea of shortening user
names


I fail to see where the conflation takes place. The ordered list is
stored on the server. The client then uses it to expand short names. I
guess I am just missing something.


The attribute is called ipaNTDomainResolutionOrder, nothing in that
attribute says anything about making names become short names.
If it were ipaNTShortNameDomainResolutionOrder then it would be
specific, as it is it seem just to refer to the order in which domain
are resolved, but that is somethign we want in order to determine which
domains SSSD is going to make use short names too, not just the order in
which domains are resolved.
I hope this makes it clearer.


- It allows only for one setting for all the machines, no way to treat
different groups of machines differently



Yes it was discussed that the setting will be global. I would implement
local overrides only when there is a demand for the feature given
development time is short.


Demand is immediate, and it is obvious IMO.



Such demand was not made clear during previous discussions and was not 
mentioned by SSSD guys either AFAIK.



The first one is probably just a matter of using a more specific name
for the new attribute, or, perhaps not use a new attribute at all but
just use ipaConfigString with an agreed syntax like:
ipaConfigString: Domains Use Short Name List: aaa bbb ccc ddd

The side effect of using ipaConfigString is that we can set this on
older servers too, so people do not have to upgrade their servers to use
this. Old servers will not have any validation, but that is ok, sssd
must be prepared to receive a bad list and deal with it appropriately
anyway.



No more 'ipaConfigString' attribute values, please. Me and everyone else
fixing e.g. replication issues can relate to the pain of doing CRUD
operations involving them.


ipaConfigString was devised explicitly so that configuration options
could be added without replication issues because the string can be
accepted by any server version.
So what replication issues are there ?
What has CRUD to do with it ?



Well consider client doing a) retrieve ipaDomainResolutionOrder and 
split it by delimiter, or b) retrieve values of ipaConfigString, iterate 
until you find one that starts with "Domains Use Short Name list:", 
strip off the rest of the value and split it by delimiter.


I just feel anything involving 'ipaConfigString' leads to design smell, 
sorry. Yes it is my personal opinion but I think there are more people 
sharing it. If not, I am happy to hear counterarguments.



If the admin wishes old servers to server new clients this information,


They do not "wish", this is pretty much what happens all the time ...


all he has to do is upgrade a single replica, set the attribute value
there and let replication take care of the rest.


Come on, really ?
If you have RHEL6 it is not a matter of "simply" upgrading a single
replica, it means upgrade of the whole infrastructure ...



There is plenty of features not available to deplyments with RHEL6 
masters, I simply fail to see why this one should be special.



Yes, the management CLI
will not be available on the old masters but that is

Re: [Freeipa-devel] Please review: V4/AD user short names design draft

On Wed, 2017-03-01 at 16:17 +0100, Martin Babinsky wrote:
> On 03/01/2017 03:42 PM, Simo Sorce wrote:
> > On Tue, 2017-02-28 at 13:29 +0100, Martin Babinsky wrote:
> >> Hello list,
> >>
> >> I have put together a draft of design page describing server-side
> >> implementation of user short name -> fully-qualified name resolution.[1]
> >>
> >> In the end I have taken the liberty to change a few aspects of the
> >> design we have agreed on before and I will be grad if we can discuss
> >> them further.
> >>
> >> Me and Honza have discussed the object that should hold the domain
> >> resolution order and given the fact that IPA domain can also be a part
> >> of this list, we have decided that this information is no longer bound
> >> to trust configuration and should be a part of the global config instead.
> >>
> >> Also we have purposefully cut down the API only to a raw manipulation of
> >> the attribute using an option of `ipa config-mod`. The reasons for this
> >> are twofold:
> >>
> >>* the developer resources are quite scarce and it may be good to
> >> follow YAGNI[2] principle to implement the dumbest API now and not to
> >> invest into more high-level interface unless there is a demand for it
> >>
> >>* we can imagine that the manipulation of the domain resolution order
> >> is a rare operation (ideally only once all trusts are established), so I
> >> am not convinced that it is worth investing into designing higher-level API
> >>
> >> I propose we first develop the "dumber" parts first to unblock the SSSD
> >> part. If we have spare cycle afterwards then we can design and implement
> >> more bells-and-whistles afterwards.
> >>
> >> [1] https://www.freeipa.org/page/V4/AD_User_Short_Names
> >> [2] https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it
> >
> > Thank you Martin,
> > this is a good initial proposal.
> >
> > I have a few issues with this design:
> > - It conflates the idea of ordering with the idea of shortening user
> > names
> 
> I fail to see where the conflation takes place. The ordered list is 
> stored on the server. The client then uses it to expand short names. I 
> guess I am just missing something.

The attribute is called ipaNTDomainResolutionOrder, nothing in that
attribute says anything about making names become short names.
If it were ipaNTShortNameDomainResolutionOrder then it would be
specific, as it is it seem just to refer to the order in which domain
are resolved, but that is somethign we want in order to determine which
domains SSSD is going to make use short names too, not just the order in
which domains are resolved.
I hope this makes it clearer.

> > - It allows only for one setting for all the machines, no way to treat
> > different groups of machines differently
> >
> 
> Yes it was discussed that the setting will be global. I would implement 
> local overrides only when there is a demand for the feature given 
> development time is short.

Demand is immediate, and it is obvious IMO.

> > The first one is probably just a matter of using a more specific name
> > for the new attribute, or, perhaps not use a new attribute at all but
> > just use ipaConfigString with an agreed syntax like:
> > ipaConfigString: Domains Use Short Name List: aaa bbb ccc ddd
> >
> > The side effect of using ipaConfigString is that we can set this on
> > older servers too, so people do not have to upgrade their servers to use
> > this. Old servers will not have any validation, but that is ok, sssd
> > must be prepared to receive a bad list and deal with it appropriately
> > anyway.
> >
> 
> No more 'ipaConfigString' attribute values, please. Me and everyone else 
> fixing e.g. replication issues can relate to the pain of doing CRUD 
> operations involving them.

ipaConfigString was devised explicitly so that configuration options
could be added without replication issues because the string can be
accepted by any server version.
So what replication issues are there ?
What has CRUD to do with it ?

> If the admin wishes old servers to server new clients this information, 

They do not "wish", this is pretty much what happens all the time ...

> all he has to do is upgrade a single replica, set the attribute value 
> there and let replication take care of the rest.

Come on, really ?
If you have RHEL6 it is not a matter of "simply" upgrading a single
replica, it means upgrade of the whole infrastructure ...

> Yes, the management CLI 
> will not be available on the old masters but that is the case of new 
> features anyway.

I do not think we need any management UI in the short term to be honest,
just a way to set a string.
That will cut most development time that can be spent instead on dealing
with allowing smaller groups of machines to be affected instead.

> > The second one is something we *may* address later, and use the setting
> > in cn=ipaConfig as a default, but there are two reasons why I think a
> > setting applicable to just a host group makes sense:
> > - it allows to

Re: [Freeipa-devel] Please review: V4/AD user short names design draft


On 03/01/2017 03:42 PM, Simo Sorce wrote:

On Tue, 2017-02-28 at 13:29 +0100, Martin Babinsky wrote:

Hello list,

I have put together a draft of design page describing server-side
implementation of user short name -> fully-qualified name resolution.[1]

In the end I have taken the liberty to change a few aspects of the
design we have agreed on before and I will be grad if we can discuss
them further.

Me and Honza have discussed the object that should hold the domain
resolution order and given the fact that IPA domain can also be a part
of this list, we have decided that this information is no longer bound
to trust configuration and should be a part of the global config instead.

Also we have purposefully cut down the API only to a raw manipulation of
the attribute using an option of `ipa config-mod`. The reasons for this
are twofold:

   * the developer resources are quite scarce and it may be good to
follow YAGNI[2] principle to implement the dumbest API now and not to
invest into more high-level interface unless there is a demand for it

   * we can imagine that the manipulation of the domain resolution order
is a rare operation (ideally only once all trusts are established), so I
am not convinced that it is worth investing into designing higher-level API

I propose we first develop the "dumber" parts first to unblock the SSSD
part. If we have spare cycle afterwards then we can design and implement
more bells-and-whistles afterwards.

[1] https://www.freeipa.org/page/V4/AD_User_Short_Names
[2] https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it


Thank you Martin,
this is a good initial proposal.

I have a few issues with this design:
- It conflates the idea of ordering with the idea of shortening user
names


I fail to see where the conflation takes place. The ordered list is 
stored on the server. The client then uses it to expand short names. I 
guess I am just missing something.



- It allows only for one setting for all the machines, no way to treat
different groups of machines differently



Yes it was discussed that the setting will be global. I would implement 
local overrides only when there is a demand for the feature given 
development time is short.



The first one is probably just a matter of using a more specific name
for the new attribute, or, perhaps not use a new attribute at all but
just use ipaConfigString with an agreed syntax like:
ipaConfigString: Domains Use Short Name List: aaa bbb ccc ddd

The side effect of using ipaConfigString is that we can set this on
older servers too, so people do not have to upgrade their servers to use
this. Old servers will not have any validation, but that is ok, sssd
must be prepared to receive a bad list and deal with it appropriately
anyway.



No more 'ipaConfigString' attribute values, please. Me and everyone else 
fixing e.g. replication issues can relate to the pain of doing CRUD 
operations involving them.


If the admin wishes old servers to server new clients this information, 
all he has to do is upgrade a single replica, set the attribute value 
there and let replication take care of the rest. Yes, the management CLI 
will not be available on the old masters but that is the case of new 
features anyway.




The second one is something we *may* address later, and use the setting
in cn=ipaConfig as a default, but there are two reasons why I think a
setting applicable to just a host group makes sense:
- it allows to test the setting on a small set of machines to see if
everything works right, this is going to be especially important on
existing setups, where people do not want to risk all machines
misbehaving at once if something goes wrong.
- it allows to migrate machines slowly, in some cases people may need to
change local files/application settings on machines if the usernames
change, so they may need a controlled roll out before changing a setting
globally.

This may achieved by adding this setting to an ID View for example, then
only hosts in that IDView would get this. Or a new object could be
created that has members, the former has the advantage of being already
in place and SSSD already downloads that data, the latter allows to
target an even smaller set of hosts unrelated to previous ID views
settings.

Simo.



That is an interesting proposal but I am afraid we may not get to 
implement that during 4.5 development. I can certainly mention the 
possibility in the design so that we can return to it when a need arises.


--
Martin^3 Babinsky

--
Manage your subscription for the Freeipa-devel mailing list:
https://www.redhat.com/mailman/listinfo/freeipa-devel
Contribute to FreeIPA: http://www.freeipa.org/page/Contribute/Code

Re: [Freeipa-devel] Please review: V4/AD user short names design draft

On Tue, 2017-02-28 at 13:29 +0100, Martin Babinsky wrote:
> Hello list,
> 
> I have put together a draft of design page describing server-side 
> implementation of user short name -> fully-qualified name resolution.[1]
> 
> In the end I have taken the liberty to change a few aspects of the 
> design we have agreed on before and I will be grad if we can discuss 
> them further.
> 
> Me and Honza have discussed the object that should hold the domain 
> resolution order and given the fact that IPA domain can also be a part 
> of this list, we have decided that this information is no longer bound 
> to trust configuration and should be a part of the global config instead.
> 
> Also we have purposefully cut down the API only to a raw manipulation of 
> the attribute using an option of `ipa config-mod`. The reasons for this 
> are twofold:
> 
>* the developer resources are quite scarce and it may be good to 
> follow YAGNI[2] principle to implement the dumbest API now and not to 
> invest into more high-level interface unless there is a demand for it
> 
>* we can imagine that the manipulation of the domain resolution order 
> is a rare operation (ideally only once all trusts are established), so I 
> am not convinced that it is worth investing into designing higher-level API
> 
> I propose we first develop the "dumber" parts first to unblock the SSSD 
> part. If we have spare cycle afterwards then we can design and implement 
> more bells-and-whistles afterwards.
> 
> [1] https://www.freeipa.org/page/V4/AD_User_Short_Names
> [2] https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it

Thank you Martin,
this is a good initial proposal.

I have a few issues with this design:
- It conflates the idea of ordering with the idea of shortening user
names
- It allows only for one setting for all the machines, no way to treat
different groups of machines differently

The first one is probably just a matter of using a more specific name
for the new attribute, or, perhaps not use a new attribute at all but
just use ipaConfigString with an agreed syntax like:
ipaConfigString: Domains Use Short Name List: aaa bbb ccc ddd

The side effect of using ipaConfigString is that we can set this on
older servers too, so people do not have to upgrade their servers to use
this. Old servers will not have any validation, but that is ok, sssd
must be prepared to receive a bad list and deal with it appropriately
anyway.


The second one is something we *may* address later, and use the setting
in cn=ipaConfig as a default, but there are two reasons why I think a
setting applicable to just a host group makes sense:
- it allows to test the setting on a small set of machines to see if
everything works right, this is going to be especially important on
existing setups, where people do not want to risk all machines
misbehaving at once if something goes wrong.
- it allows to migrate machines slowly, in some cases people may need to
change local files/application settings on machines if the usernames
change, so they may need a controlled roll out before changing a setting
globally.

This may achieved by adding this setting to an ID View for example, then
only hosts in that IDView would get this. Or a new object could be
created that has members, the former has the advantage of being already
in place and SSSD already downloads that data, the latter allows to
target an even smaller set of hosts unrelated to previous ID views
settings.

Simo.

-- 
Simo Sorce * Red Hat, Inc * New York

-- 
Manage your subscription for the Freeipa-devel mailing list:
https://www.redhat.com/mailman/listinfo/freeipa-devel
Contribute to FreeIPA: http://www.freeipa.org/page/Contribute/Code

Re: [Freeipa-devel] Please review: V4/AD user short names design draft


On ke, 01 maalis 2017, Jan Cholasta wrote:

On 1.3.2017 14:05, Alexander Bokovoy wrote:

On ke, 01 maalis 2017, Jan Cholasta wrote:

On 1.3.2017 13:39, Martin Babinsky wrote:

Alexander,

thank you for your comments. Replies inline:

On 02/28/2017 01:48 PM, Alexander Bokovoy wrote:

On ti, 28 helmi 2017, Martin Babinsky wrote:

Hello list,

I have put together a draft of design page describing server-side
implementation of user short name -> fully-qualified name
resolution.[1]

In the end I have taken the liberty to change a few aspects of the
design we have agreed on before and I will be grad if we can discuss
them further.

Me and Honza have discussed the object that should hold the domain
resolution order and given the fact that IPA domain can also be a part
of this list, we have decided that this information is no longer bound
to trust configuration and should be a part of the global config
instead.

Also we have purposefully cut down the API only to a raw manipulation
of the attribute using an option of `ipa config-mod`. The reasons for
this are twofold:

* the developer resources are quite scarce and it may be good to
follow YAGNI[2] principle to implement the dumbest API now and not to
invest into more high-level interface unless there is a demand for it

* we can imagine that the manipulation of the domain resolution order
is a rare operation (ideally only once all trusts are established), so
I am not convinced that it is worth investing into designing
higher-level API

I propose we first develop the "dumber" parts first to unblock the
SSSD part. If we have spare cycle afterwards then we can design and
implement more bells-and-whistles afterwards.

Looks mostly OK, but there are few comments I have:

- I do not see you mention how validation of the
ipaDomainResolutionOrder is done. This is important to avoid hard to
debug issues because SSSD will ignore domains it doesn't know about.



The validation is described in a Design section as follows:

"""
Finally, any modification of the domain resolution order must ensure
that each of the specified domain names corresponds either to that of
FreeIPA domain or to one of the trusted AD domains stored in LDAP
backend. In the case of trusted domains, the domain must not be marked
as disabled.
"""

Is this sufficient or is a more thorough validation required? Shall I
split the whole section into sub-sections for easier navigation?


- Space separator initially caused me to look up DNS RFCs as strictly
speaking domain names can contain any 8-bit octet (while host names
should follow LDH rule). But then [1] does explicitly say space is not
allowed in AD domain names.



I have discussed this with Jan and consulted the same document that you
cited, that's why I have arrived to the conclusion to use whitespace as
separator. Jakub/Fabiano, is this ok with the way SSSD decodes domain
names or should we consider other options to avoid breakage with more
exotic domain names?


Actually I would prefer something else than whitespace as a separator.
A ':' maybe?

or ',' or ';'. Any would work.


I have considered a empty attribute value to be a distinct state from
the missing attribute and assigned a different semantic meaning to it.

The reasoning is as follows: if the attribute is not set, SSSD will not
retrieve it and this signals that it should continue operate in usual
way.

If the attribute is present but is empty, the semantics change slightly
as now we consider *no* domains during short name resolution (extension
of the missing domain behavior to the case of all domains are missing
from list).


It doesn't have to be literally empty (LDAP character string syntaxes
don't allow it anyway IIRC), there can be a value which denotes an
empty list of domain (e.g. the separator alone).

I don't see *why* there should be this distinction. The deciding party
is SSSD. Whether this attirbute exists and empty or does not exist at
all does not change anything. Changing how SSSD interprets own defaults
depending on absense or emptiness of certain attribute in IPA config
object is not user friendly at all.

SSSD default behavior should stay the same whether it finds missing or
empty attribute because the attribute will not be known to older SSSD
anyway. Missing or empty attribute should, in my opinion, be equal to
older SSSD behavior.



"No value is set in configuration => use built-in default / some value 
is set configuration => use the value" is perfectly user friendly and 
pretty much common virtually everywhere I believe, much more so than 
"empty value is set in configuration => ignore the value even if the 
user deliberately set it empty and use the default value instead".

I'm not arguing with "no value is set in configuration -> use built-in
default". I do argue on having empty but present attribute because it
does not add anything useful for SSSD to decide on. And as it is not
adding anything useful, why there should be such difference at all?

This is the only

Re: [Freeipa-devel] Please review: V4/AD user short names design draft

2017-03-01 Thread Jan Cholasta


On 1.3.2017 14:05, Alexander Bokovoy wrote:

On ke, 01 maalis 2017, Jan Cholasta wrote:

On 1.3.2017 13:39, Martin Babinsky wrote:

Alexander,

thank you for your comments. Replies inline:

On 02/28/2017 01:48 PM, Alexander Bokovoy wrote:

On ti, 28 helmi 2017, Martin Babinsky wrote:

Hello list,

I have put together a draft of design page describing server-side
implementation of user short name -> fully-qualified name
resolution.[1]

In the end I have taken the liberty to change a few aspects of the
design we have agreed on before and I will be grad if we can discuss
them further.

Me and Honza have discussed the object that should hold the domain
resolution order and given the fact that IPA domain can also be a part
of this list, we have decided that this information is no longer bound
to trust configuration and should be a part of the global config
instead.

Also we have purposefully cut down the API only to a raw manipulation
of the attribute using an option of `ipa config-mod`. The reasons for
this are twofold:

* the developer resources are quite scarce and it may be good to
follow YAGNI[2] principle to implement the dumbest API now and not to
invest into more high-level interface unless there is a demand for it

* we can imagine that the manipulation of the domain resolution order
is a rare operation (ideally only once all trusts are established), so
I am not convinced that it is worth investing into designing
higher-level API

I propose we first develop the "dumber" parts first to unblock the
SSSD part. If we have spare cycle afterwards then we can design and
implement more bells-and-whistles afterwards.

Looks mostly OK, but there are few comments I have:

- I do not see you mention how validation of the
ipaDomainResolutionOrder is done. This is important to avoid hard to
debug issues because SSSD will ignore domains it doesn't know about.



The validation is described in a Design section as follows:

"""
Finally, any modification of the domain resolution order must ensure
that each of the specified domain names corresponds either to that of
FreeIPA domain or to one of the trusted AD domains stored in LDAP
backend. In the case of trusted domains, the domain must not be marked
as disabled.
"""

Is this sufficient or is a more thorough validation required? Shall I
split the whole section into sub-sections for easier navigation?


- Space separator initially caused me to look up DNS RFCs as strictly
speaking domain names can contain any 8-bit octet (while host names
should follow LDH rule). But then [1] does explicitly say space is not
allowed in AD domain names.



I have discussed this with Jan and consulted the same document that you
cited, that's why I have arrived to the conclusion to use whitespace as
separator. Jakub/Fabiano, is this ok with the way SSSD decodes domain
names or should we consider other options to avoid breakage with more
exotic domain names?


Actually I would prefer something else than whitespace as a separator.
A ':' maybe?

or ',' or ';'. Any would work.


I have considered a empty attribute value to be a distinct state from
the missing attribute and assigned a different semantic meaning to it.

The reasoning is as follows: if the attribute is not set, SSSD will not
retrieve it and this signals that it should continue operate in usual
way.

If the attribute is present but is empty, the semantics change slightly
as now we consider *no* domains during short name resolution (extension
of the missing domain behavior to the case of all domains are missing
from list).


It doesn't have to be literally empty (LDAP character string syntaxes
don't allow it anyway IIRC), there can be a value which denotes an
empty list of domain (e.g. the separator alone).

I don't see *why* there should be this distinction. The deciding party
is SSSD. Whether this attirbute exists and empty or does not exist at
all does not change anything. Changing how SSSD interprets own defaults
depending on absense or emptiness of certain attribute in IPA config
object is not user friendly at all.

SSSD default behavior should stay the same whether it finds missing or
empty attribute because the attribute will not be known to older SSSD
anyway. Missing or empty attribute should, in my opinion, be equal to
older SSSD behavior.



"No value is set in configuration => use built-in default / some value 
is set configuration => use the value" is perfectly user friendly and 
pretty much common virtually everywhere I believe, much more so than 
"empty value is set in configuration => ignore the value even if the 
user deliberately set it empty and use the default value instead".


--
Jan Cholasta

--
Manage your subscription for the Freeipa-devel mailing list:
https://www.redhat.com/mailman/listinfo/freeipa-devel
Contribute to FreeIPA: http://www.freeipa.org/page/Contribute/Code

Re: [Freeipa-devel] Please review: V4/AD user short names design draft


On ke, 01 maalis 2017, Martin Babinsky wrote:

Alexander,

thank you for your comments. Replies inline:

On 02/28/2017 01:48 PM, Alexander Bokovoy wrote:

On ti, 28 helmi 2017, Martin Babinsky wrote:

Hello list,

I have put together a draft of design page describing server-side
implementation of user short name -> fully-qualified name resolution.[1]

In the end I have taken the liberty to change a few aspects of the
design we have agreed on before and I will be grad if we can discuss
them further.

Me and Honza have discussed the object that should hold the domain
resolution order and given the fact that IPA domain can also be a part
of this list, we have decided that this information is no longer bound
to trust configuration and should be a part of the global config instead.

Also we have purposefully cut down the API only to a raw manipulation
of the attribute using an option of `ipa config-mod`. The reasons for
this are twofold:

* the developer resources are quite scarce and it may be good to
follow YAGNI[2] principle to implement the dumbest API now and not to
invest into more high-level interface unless there is a demand for it

* we can imagine that the manipulation of the domain resolution order
is a rare operation (ideally only once all trusts are established), so
I am not convinced that it is worth investing into designing
higher-level API

I propose we first develop the "dumber" parts first to unblock the
SSSD part. If we have spare cycle afterwards then we can design and
implement more bells-and-whistles afterwards.

Looks mostly OK, but there are few comments I have:

- I do not see you mention how validation of the
ipaDomainResolutionOrder is done. This is important to avoid hard to
debug issues because SSSD will ignore domains it doesn't know about.



The validation is described in a Design section as follows:

"""
Finally, any modification of the domain resolution order must ensure 
that each of the specified domain names corresponds either to that of 
FreeIPA domain or to one of the trusted AD domains stored in LDAP 
backend. In the case of trusted domains, the domain must not be marked 
as disabled.

"""

Is this sufficient or is a more thorough validation required? Shall I 
split the whole section into sub-sections for easier navigation?

I think it would be good to increase visibility by making subsections.

However, I'd like to spell it out that trusted forest root domain is
also verified on the list. We have trusts structured hierarchically,
this means both levels have to be checked.


- Space separator initially caused me to look up DNS RFCs as strictly
speaking domain names can contain any 8-bit octet (while host names
should follow LDH rule). But then [1] does explicitly say space is not
allowed in AD domain names.



I have discussed this with Jan and consulted the same document that 
you cited, that's why I have arrived to the conclusion to use 
whitespace as separator. Jakub/Fabiano, is this ok with the way SSSD 
decodes domain names or should we consider other options to avoid 
breakage with more exotic domain names?



- "If ipaDomainResolutionOrder is empty then *all* users must use fully
qualified names." This is not correct with regards to the current
behavior. I think we should change this to "if
ipaDomainResolutionOrder is empty, then standard SSSD configuration
logic applies on each client." This would make current behavior
compatible with either empty or ipaDomainResolutionOrder value of
a single IPA domain name.



I have considered a empty attribute value to be a distinct state from 
the missing attribute and assigned a different semantic meaning to it.


The reasoning is as follows: if the attribute is not set, SSSD will 
not retrieve it and this signals that it should continue operate in 
usual way.


If the attribute is present but is empty, the semantics change 
slightly as now we consider *no* domains during short name resolution 
(extension of the missing domain behavior to the case of all domains 
are missing from list).

I'd rather avoid making this distinction. You always can override things
on SSSD side and default on SSSD side is to *not* use fully qualified
domain names for a domain.

I don't think we have any use case of having all domains with fully
qualified names. Even in case of NFS and sss_rpcidmapd, SSSD will
happily handle both non-fully qualified names and fully qualified ones.

--
/ Alexander Bokovoy

--
Manage your subscription for the Freeipa-devel mailing list:
https://www.redhat.com/mailman/listinfo/freeipa-devel
Contribute to FreeIPA: http://www.freeipa.org/page/Contribute/Code

Re: [Freeipa-devel] Please review: V4/AD user short names design draft

2017-03-01 Thread Jan Cholasta

On 1.3.2017 13:39, Martin Babinsky wrote:

Alexander,

thank you for your comments. Replies inline:

On 02/28/2017 01:48 PM, Alexander Bokovoy wrote:

On ti, 28 helmi 2017, Martin Babinsky wrote:

Hello list,

I have put together a draft of design page describing server-side
implementation of user short name -> fully-qualified name resolution.[1]

In the end I have taken the liberty to change a few aspects of the
design we have agreed on before and I will be grad if we can discuss
them further.

Me and Honza have discussed the object that should hold the domain
resolution order and given the fact that IPA domain can also be a part
of this list, we have decided that this information is no longer bound
to trust configuration and should be a part of the global config
instead.

Also we have purposefully cut down the API only to a raw manipulation
of the attribute using an option of `ipa config-mod`. The reasons for
this are twofold:

* the developer resources are quite scarce and it may be good to
follow YAGNI[2] principle to implement the dumbest API now and not to
invest into more high-level interface unless there is a demand for it

* we can imagine that the manipulation of the domain resolution order
is a rare operation (ideally only once all trusts are established), so
I am not convinced that it is worth investing into designing
higher-level API

I propose we first develop the "dumber" parts first to unblock the
SSSD part. If we have spare cycle afterwards then we can design and
implement more bells-and-whistles afterwards.

Looks mostly OK, but there are few comments I have:

- I do not see you mention how validation of the
ipaDomainResolutionOrder is done. This is important to avoid hard to
debug issues because SSSD will ignore domains it doesn't know about.

The validation is described in a Design section as follows:

"""
Finally, any modification of the domain resolution order must ensure
that each of the specified domain names corresponds either to that of
FreeIPA domain or to one of the trusted AD domains stored in LDAP
backend. In the case of trusted domains, the domain must not be marked
as disabled.
"""

Is this sufficient or is a more thorough validation required? Shall I
split the whole section into sub-sections for easier navigation?

- Space separator initially caused me to look up DNS RFCs as strictly
speaking domain names can contain any 8-bit octet (while host names
should follow LDH rule). But then [1] does explicitly say space is not
allowed in AD domain names.

I have discussed this with Jan and consulted the same document that you
cited, that's why I have arrived to the conclusion to use whitespace as
separator. Jakub/Fabiano, is this ok with the way SSSD decodes domain
names or should we consider other options to avoid breakage with more
exotic domain names?

Actually I would prefer something else than whitespace as a separator. A
':' maybe?

- "If ipaDomainResolutionOrder is empty then *all* users must use fully
qualified names." This is not correct with regards to the current
behavior. I think we should change this to "if
ipaDomainResolutionOrder is empty, then standard SSSD configuration
logic applies on each client." This would make current behavior
compatible with either empty or ipaDomainResolutionOrder value of
a single IPA domain name.

I have considered a empty attribute value to be a distinct state from
the missing attribute and assigned a different semantic meaning to it.

The reasoning is as follows: if the attribute is not set, SSSD will not
retrieve it and this signals that it should continue operate in usual way.

If the attribute is present but is empty, the semantics change slightly
as now we consider *no* domains during short name resolution (extension
of the missing domain behavior to the case of all domains are missing
from list).

It doesn't have to be literally empty (LDAP character string syntaxes
don't allow it anyway IIRC), there can be a value which denotes an empty
list of domain (e.g. the separator alone).

That is however open to discussion and I think we can even get away from
this by letting SSSD guys to decide how to handle this case.

- There are typos in the page.

I know there was not much proofreading involved in this iteration. I
have already tried to fix them.

[1]
https://support.microsoft.com/en-us/help/909264/naming-conventions-in-active-directory-for-computers,-domains,-sites,-and-ous

--
Jan Cholasta

--
Manage your subscription for the Freeipa-devel mailing list:
https://www.redhat.com/mailman/listinfo/freeipa-devel
Contribute to FreeIPA: http://www.freeipa.org/page/Contribute/Code

Re: [Freeipa-devel] Please review: V4/AD user short names design draft

Alexander,

thank you for your comments. Replies inline:

On 02/28/2017 01:48 PM, Alexander Bokovoy wrote:

On ti, 28 helmi 2017, Martin Babinsky wrote:

Hello list,

I have put together a draft of design page describing server-side
implementation of user short name -> fully-qualified name resolution.[1]

In the end I have taken the liberty to change a few aspects of the
design we have agreed on before and I will be grad if we can discuss
them further.

Also we have purposefully cut down the API only to a raw manipulation
of the attribute using an option of `ipa config-mod`. The reasons for
this are twofold:

I propose we first develop the "dumber" parts first to unblock the
SSSD part. If we have spare cycle afterwards then we can design and
implement more bells-and-whistles afterwards.

Looks mostly OK, but there are few comments I have:

- I do not see you mention how validation of the
ipaDomainResolutionOrder is done. This is important to avoid hard to
debug issues because SSSD will ignore domains it doesn't know about.

The validation is described in a Design section as follows:

"""

Is this sufficient or is a more thorough validation required? Shall I
split the whole section into sub-sections for easier navigation?

I have considered a empty attribute value to be a distinct state from
the missing attribute and assigned a different semantic meaning to it.

The reasoning is as follows: if the attribute is not set, SSSD will not
retrieve it and this signals that it should continue operate in usual way.

That is however open to discussion and I think we can even get away from
this by letting SSSD guys to decide how to handle this case.

- There are typos in the page.

I know there was not much proofreading involved in this iteration. I
have already tried to fix them.

[1]
https://support.microsoft.com/en-us/help/909264/naming-conventions-in-active-directory-for-computers,-domains,-sites,-and-ous

--
Martin^3 Babinsky

--
Manage your subscription for the Freeipa-devel mailing list:
https://www.redhat.com/mailman/listinfo/freeipa-devel
Contribute to FreeIPA: http://www.freeipa.org/page/Contribute/Code

Re: [Freeipa-devel] Please review: V4/AD user short names design draft