[Date Prev][Date Next] [Chronological] [Thread] [Top]

Re: create new user with same UID and GID

Ulrich Windl wrote:
>>>> Michael Ströder<michael@stroeder.com> schrieb am 21.02.2015 um 20:06 in
> Nachricht <54E8D726.30503@stroeder.com>:
>> Bernd May wrote:
> [...]
>>> You could also create a dummy user account that stores the next usable
>>> gid/uid pair (which you acquired once with the previous algorithm) and
>>> then query that account each time you create a new user, increase its
>>> gid and uid values and create your new user. This assumes some kind of
>>> conflict free numbering scheme of your users by which you can infer the
>>> next free number pair automatically.
>> The problem with id pool entries (kind of a sequence generator) is that ids
>> might be consumed without being really used. Therefore for numeric ids it's
>> a
>> better approach to search for all entries, use reverse server-side sorting 
>> and
>> only query one result to get the highest id.
> But that's somewhat "performance-heavy" I guess. What could help here would be
> transactions (actually nested transactions). Consume a UID/GID and assign it to
> a new entry in one transaction.

This would only help in case the second write operation fails.

But the more likely problem is that the user might abort the use-case.  Of
course it depends when the client actually generates the id.  In case of my
web2ldap I present the generated id in the input form so the user could
manually change it if needed.  But the user might not hit the submit button.


Ciao, Michael.

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature