On 03/05/2015 07:55 AM, Jan Kaluža wrote: > Hi, > > currently, the External Rewriting Program (RewriteMap "prg:") is run as root. > I would like to change it but I see three > ways how to do it: > > 1. Execute it right after drop_privileges hook. This looks like best way, but > I haven't found any hook which could be > used for that (except drop_privileges with APR_HOOK_REALLY_LAST, which does > not seem as proper place to me). > > 2. Execute it in child_init. This is done after drop_privileges, so the > user/group is good. The "problem" here is that > it would execute one rewrite program per child. Right now I'm not sure if > it's really problem. It could be useful to > have more instances of rewriting program to make its bottleneck lower. > > 3. Execute it where it is now (post_config), but set user/group using > apr_procattr_t. So far I think this would > duplicate the code of mod_unixd and would probably have to also handle the > windows equivalent of that module (if there's > any). > > What way do you think is the best, or would you do it differently? > > I'm attaching patch for number 2.
I would tend to 2. as well, but as far as I remember using the rewritemap program is synchronized across all processes. This raises two questions: 1. Does rewriting still work with the current patch? 2. If it does can stuff be optimized to move from a server wide lock to a process wide lock (or even no lock for prefork) to remove the contention here? OTOH looking at the topic of backwards compatibility existing rewrite programs might rely on not working in parallel. Some may even have an issue if more then one copy of them is running in parallel, albeit not processing stuff in parallel which of course would cause an issue with the proposed patch. Furthermore existing setups might expect to be run as root. But this stuff only needs to be considered when we think about backporting and is moot for trunk. Regards Rüdiger
