mod_perl seems to be sharing modules across user accounts

Question

Please do ask if you need any more information. I'm just trying to work out what is going on. So I have a server with nginx as the front end, and then passing along to Apache (2.4.18). In my Apache config file for the domain I have:

<VirtualHost *:8181>

    CustomLog /home/steampunkcom/web/uk.site.com/logs/uk.site.com.apache.log combined
    ErrorLog /home/steampunkcom/web/uk.site.com/logs/uk.site.com.apache.error.log

    LogLevel error

    RemoteIPHeader X-Forwarded-For

    # MOD_PERL
    LoadModule perl_module /usr/lib/apache2/modules/mod_perl.so

    ServerName uk.site.com
    ServerAlias www.uk.site.com
    ServerAdmin info@uk.site.com
    DocumentRoot /home/steampunkcom/web/uk.site.com/public_html

    # MOD_PERL
    PerlRequire  /home/steampunkcom/web/uk.site.com/startup.pl

    ScriptAlias /cgi-bin/ /home/steampunkcom/web/uk.site.com/public_html/cgi-bin/

    Alias /vstats/ /home/steampunkcom/web/uk.site.com/stats/
    Alias /error/ /home/steampunkcom/web/uk.site.com/document_errors/


    # Uncomment this part to make run as mod_perl - comment out above as well!
    <Directory "/home/steampunkcom/web/uk.site.com/*">

        Options +ExecCGI +FollowSymLinks +MultiViews
        AllowOverride AuthConfig

        PerlResponseHandler ModPerl::Registry
        AddHandler perl-script .cgi .pl
        Options +ExecCGI
        PerlOptions +ParseHeaders
        AllowOverride All
        Require all granted

    </Directory>

    <Directory /home/steampunkcom/web/uk.site.com/stats>
       AllowOverride All
       Require all granted
    </Directory>


    <IfModule mod_ruid2.c>
        RMode config
        RUidGid steampunkcom steampunkcom
        RGroups www-data
    </IfModule>
    <IfModule itk.c>
        AssignUserID steampunkcom steampunkcom
    </IfModule>

    IncludeOptional /home/steampunkcom/conf/web/apache2.uk.site.com.conf*

</VirtualHost>

This works fine. It runs under mod_perl well. The issue arises when I try and enable mod_perl on another user account:

<VirtualHost *:8181>

    CustomLog /home/willr/web/anothersite.co.uk/logs/anothersite.co.uk.apache.log combined
    ErrorLog /home/willr/web/anothersite.co.uk/logs/anothersite.co.uk.apache.error.log

    LogLevel error

    RemoteIPHeader X-Forwarded-For

    LoadModule perl_module /usr/lib/apache2/modules/mod_perl.so

    PerlRequire  /home/willr/web/anothersite.co.uk/startup.pl

    ServerName anothersite.co.uk
    ServerAlias www.anothersite.co.uk
    ServerAdmin info@anothersite.co.uk
    DocumentRoot /home/willr/web/anothersite.co.uk/public_html


    #####
    ScriptAlias /cgi-bin/ /home/willr/web/anothersite.co.uk/public_html/cgi-bin/
    #####

    Alias /vstats/ /home/willr/web/anothersite.co.uk/stats/
    Alias /error/ /home/willr/web/anothersite.co.uk/document_errors/

    <Directory "/home/willr/web/anothersite.co.uk/*">
        Options +ExecCGI +FollowSymLinks +MultiViews
        AllowOverride AuthConfig

        PerlResponseHandler ModPerl::Registry
        AddHandler perl-script .cgi .pl
        Options +ExecCGI
        PerlOptions +ParseHeaders
        AllowOverride All
        Require all granted

    </Directory>


    <IfModule mod_ruid2.c>
        RMode config
        RUidGid willr willr
        RGroups www-data
    </IfModule>
    <IfModule itk.c>
        AssignUserID willr willr
    </IfModule>

</VirtualHost>

At first I thought it was all working fine, but then I started getting emails from people telling me they couldn't log into the site. Upon looking into it, I found that it was sharing a module across the user accounts. I'm trying to figure out why, and what I can do about it. I know for a fact mod_perl can run across multiple user accounts without sharing the modules (as I've done it on other servers that were managed for me), but I'm not sure how/ why its doing it here.

Any ideas are much appreciated! In the meantime I've had to disable mod_perl for one of the sites, as it was causing too many issues for the other site :(

I just found something about using the +Parent and PerlSwitches config:

 <VirtualHost ...>
      ServerName dev1
      PerlOptions +Parent
      PerlSwitches -I/home/dev1/lib/perl
  </VirtualHost>

https://perl.apache.org/docs/2.0/user/config/config.html#C_Parent_

The problem though is that it still seems to cause the modules to get "shared" across other user accounts. So I have:

PerlOptions +ParseHeaders +Parent
PerlSwitches -Mlib=/home/steampunkcom/web/foo.co.uk/lib

When I look at the contents of @INC, I can see:

@INC = 
    /home/steampunkcom/web/foo.com/public_html/cgi-bin/admin
    /home/steampunkcom/web/foo.com/lib
    /etc/perl
    /usr/local/lib/x86_64-linux-gnu/perl/5.22.1
    /usr/local/share/perl/5.22.1
    /usr/lib/x86_64-linux-gnu/perl5/5.22
    /usr/share/perl5
    /usr/lib/x86_64-linux-gnu/perl/5.22
    /usr/share/perl/5.22
    /usr/local/lib/site_perl
    .
    /etc/apache2

I really thought I had a solution there, but maybe not :(

@wazoox thanks - I've replied there (not sure if you get notified, as I don't get emails when someone replies to me on PM) — Andrew Newby, Mar 20 '19 at 07:12
@wazoox hmmm yeah doesn't seem to work. Here are what I have (trimmed for sensative info) https://pastebin.com/1R2xeaxh , https://pastebin.com/LxXcsyxp — Andrew Newby, Mar 20 '19 at 07:18
you're not showing the other vhost. I'm pretty sure you must set the perl options for all the vhosts (because the default is "always share"). — wazoox, Mar 20 '19 at 15:23
@wazoox not sure what you mean? Those 2 pastebins are the different sites - unless you mean something else? There is only 2 sites that have mod_perl enabled (was one before, and now I'm trying to add a 2nd one, which is where the problem is coming from)( — Andrew Newby, Mar 20 '19 at 15:30
I just went through all the servers .conf files for Apache (the domains), and can confirm that the 2 in question have ` PerlOptions +Parent PerlInterpStart 2 PerlInterpMax 2` , but it still seems to share :( — Andrew Newby, Mar 20 '19 at 15:50
The frustrating part is that according to this: https://perl.apache.org/docs/2.0/user/config/config.html#C_GlobalRequest_ , you should be able to put those values in the , but when restarting you get: `Invalid per-directory PerlOption: Parent` — Andrew Newby, Mar 20 '19 at 16:05

score 1 · Accepted Answer · answered Mar 20 '19 at 16:19

OK so this seems to work.

PerlOptions +Parent
PerlInterpStart 2
PerlInterpMax 2
PerlSwitches -Mlib=/home/steampunkcom/web/uk.domain.com/lib
PerlRequire  /home/steampunkcom/web/uk.domain.com/startup.pl # my script to auto load modules

It seems the order is important as well. I'm not sure if this was part of the solution as well, but I gave the server a reboot. I'm wondering if maybe something got "stuck" when I was playing with the settings, and no matter how many time I restarted Apache it wouldn't fix the issue.

Anyway - I think this has sorted it! At least I'm not seeming to get clashing modules any more.

mod_perl seems to be sharing modules across user accounts

1 Answers1