Re: Changing apache config with mod_perl, doesnt work!

On 09-11-22 17:42 , Devrim Yasar wrote:
> This script supposedly should take * out of *.domain.com, assign it to
> $subdomain variable, and $subdomain should be put to AssignUserId.
> 
> However, no matter how hard I try, I can't get this to work. I've been
> working on this for days, and am really desperate. If you think this is
> a lot of work, please charge me consultancy and come get the root passwd.
> 
> Any ideas though? Thanks...
> 
> |<Perl>
>  Use Apache2::ServerRec qw//; 
>  use Apache2::ServerUtil qw//; 
>  use Apache2::RequestRec qw//; 
>  use Apache2::RequestUtil qw//; 
>  use Apache2::Const qw/OK DECLINED/; 
> 
>  my $s = Apache2::ServerUtil->server; 
> 
>  $s->push_handlers(PerlHeaderParserHandler => sub { my($r) = @_; 

From a quick glance at the mpm-itk source-code, it does its magic in at
the headerparsing phase, so your attempt at using that phase to alter
it's behaviour was a good one.

 /* set the uid as fast as possible, but not before merging per-dit
config */
 ap_hook_header_parser(itk_post_perdir_config, NULL, NULL,
APR_HOOK_REALLY_FIRST);

Unfortunately, it seems to pick APR_HOOK_REALLY_FIRST as precedence,
which makes it run /before/ your code, in the same phase. So, even
though you actually succeed at changing it's run-time configuration, you
do it too late, and it doesn't even look at it.

>  if ( $r->hostname =~ m/(.*)\.([^.]+\.\w+)$/ ) { 
>  my($subdomain,$domain) = ($1,$2); 
> 
>  #
>  # THIS WORKS!
>  # -----------
>  # if requested domain is fio.domain.com <http://fio.domain.com/>,
>  # this successfully assigns ServerAdmin [email protected] <mailto:[email protected]>
>  # so gathering domain parts working
> 
>  $r->server->server_admin("$subdomain\@$domain");

Yes, as expected, and it uses a published API to do that.

>  #
>  # THIS DOESN'T!
>  # --------------
>  # this is supposed to insert this line inside Virtual host
>  # --------------
>  # <IfModule mpm_itk_module> AssignUserId fio domain</IfModule>
>  # --------------
> 
>  $r->add_config([ "<IfModule mpm_itk_module>", 
>  "AssignUserId $subdomain $domain", 
>  "</IfModule>", 
>  ]); 
> 

Except for my above explanation, this would work just fine. I would
however caution about using this kind of mechanism to alter run-time
configuration on a per-request basis. This comes at a non-negligable
performance impact, if that's important to your usage scenario.

Ideally, like in the server_admin() case outlined above, mpm-itk
could/should expose an API to allow for changing the userid/domain.

You could try and use PerlMapToStorageHandler as your phase, since it
happens before the PerlHeaderParserHandler phase.

-- 
Philippe M. Chiasson     GPG: F9BFE0C2480E7680 1AE53631CB32A107 88C3A5A5
http://gozer.ectoplasm.org/       m/gozer\@(apache|cpan|ectoplasm)\.org/

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