in reply to How to change the userid of a running external process

This sounds like an XY problem to me. What are you trying to do?

Alex / talexb / Toronto

"Groklaw is the open-source mentality applied to legal research" ~ Linus Torvalds

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Re^2: How to change the userid of a running external process
by macron0 (Novice) on Jul 22, 2010 at 07:49 UTC

    Hello Monks,

    Thank you for your reply's

    What I am trying to do is change an apache child to the user and group id's that matches the vhost when a request comes in.

    I managed to do this in mod_perl but the problem is that once changed to a certain userid you cannot go back (which makes sense). and apache had to run as root which is also a bit....

    So the only option is to only use the child once and let it die or (and I haven't figured out how to do this) remember which userid a child has and once a next request comes in reuse this child. But this seems impossible in apache since thehe connection get passed to a child and only after wards it gets decided which vhost it should handle.

    So I thought it would be nice if I could have a child signal a process running as root and have that process change the childs id and when the child signals it's finished finishes change it back.

    In the responses I got so far it seems this is rather impossible or causes very much overhead.

    But if anyone has a good suggestion for this it would be appriciated.

    Regards

    Hans

[reply]
      What I am trying to do is change an apache child to the user and group id's that matches the vhost when a request comes in.

      Why do you think you need to do that?

      Search the Apache documentation for suexec if you need to run code under a different user ID. Also think about using static FastCGI servers: They can run under any user ID you like, and if they crash, they don't kill the entire webserver.

      Alexander

      --
      Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)
[reply]

        Suexec and suphp are the reason I am trying this.

        It gives loads of complications since apache keeps running as apache so generated files (like uploaded images) must have permissions in a way that apache kan read it.

        And suphp sort of cancels the whole point of php (being fast) and also has many other problems.

        So any of the cgi options are not what I am looking for.

        And I use embperl for my own sites

        I think (but I am not sure) it would all ready be much faster than suphp if I fork a child, change to the userid of the child to what I need and then let the forked child die when it is done, every request. But I still think this solution is a bad idea too.

        So I am still looking for a way to have a process with root permissions change other processes userids.

        Help?</?>

[reply]

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