Re: Can postfix/pipe run external programs under a random UID?

2019-09-06 Thread Wietse Venema
Leonid Isaev:
> Hello,
> 
>   One of arguments of pipe(8) is "user=" that instructs it to run an
> external programunder specified user. For example, the following snippet will
> run faxmail(1) under the user faxmail:
> -8<-
> fax   unix   -  nn  -   1   pipe
>   flags= user=faxmail argv=/usr/bin/faxmail -d -n ${user}
> ->8-
> 
> Is it possible to have postfix select user at random from some list of
> preallocated UIDs/usernames? (I'm looking for ways to isolate different
> instances of the same command)

The user attribute takes a fixed username, not a lookup table.

You can use 

/etc/postfix/main.cf:
transport_maps = randmap:{fax1:, fax2:, ...}

to randomly invoke different fax transports, each with their own
fixed username.

Of course random selection is subject to collisions.

Wietse


Can postfix/pipe run external programs under a random UID?

2019-09-06 Thread Leonid Isaev
Hello,

One of arguments of pipe(8) is "user=" that instructs it to run an
external programunder specified user. For example, the following snippet will
run faxmail(1) under the user faxmail:
-8<-
fax   unix   -  nn  -   1   pipe
  flags= user=faxmail argv=/usr/bin/faxmail -d -n ${user}
->8-

Is it possible to have postfix select user at random from some list of
preallocated UIDs/usernames? (I'm looking for ways to isolate different
instances of the same command)

Thanks,
-- 
Leonid Isaev