You might or might not remember my fighting with mod_perl and my finding a bug in the handling of logs if Apache’s error log is set to use the syslog interface (which in my case would be metalog). For those wondering the upstream bug is still untouched goes without saying. This should have told me that there aren’t many people using Apache’s syslog support, but sometimes I’m stubborn.
Anyway, yesterday I finally put into so-called “production” the webapp I described last week for handling customers’ computers. I got it working in no time after mongoid started to behave (tests are still restricted, because a couple fail and I’m not sure why — I’ll have to work on that with the next release that require quite fewer hacks to test cleanly). I did encounter a nasty bug in best_in_place which I ended up fixing in Gentoo even though upstream hasn’t merged my branch yet.
To get it in “production” I simply mean configuring it to run on the twin server of this blog’s, which I’ve been using for another customer as well — and got ready for a third. Since Rails 3.1 was already installed on that box, it was quite easy to move my new app there. All it took was installing the few new gems I needed and…
Well here’s the interesting thing: I didn’t want for my application to run as my user, while obviously I wanted to check out the sources with my user so that I could get it to update with git … how do you do that? Well, Passenger is able to run the application under whatever user owns the config/environment.rb file, so you’d expect it to be able to run under an arbitrary user as well — which is the case, but only if you’re using version 3 (which is not stable in Gentoo as of yet).
So anyway I set up the new passenger to change the user, make public/assets/ and another directory I write to group-writable (the app user and my user are in the same group), and then I’m basically done, I think. I start up and I’m done with it, I think… but the hostnames tell me that “something went wrong”, without any clue as to what.
Okay so the default for Passenger is to not have any log at all, not a problem, I’ll just increase the level to 1 and see the error… or not? I still get no output in Apache’s error log .. which is still set to syslog… don’t tell me… I set Passenger to log to file, and lo and behold it works fine. I wonder if it’s time for me to learn Apache’s API and get to fix both, since it looks like I’m one of the very few people who would like to use syslog as Apache’s error log.
After getting Passenger to finally tell me what’s wrong, I find out both the reason why Rails wasn’t starting (I forgot to enable two USE flags in dev-ruby/barby which I use for generating the QR code on the label), but I also see this:
Rails Error: Unable to access log file. Please ensure that /var/www/${vhost}/log/production.log exists and is chmod 0666. The log level has been raised to WARN and the output directed to STDERR until the problem is fixed.
Please note that logging negatively impacts client-side performance. You should set your logging level no lower than :info in production.
What? Rails is really telling its users to create a world writeable log file, when it fails to write to it? Are they freaking kidding me? Is this really a suggestion coming from the developers of a framework for Web Applications which should be security-sensitive? … Okay so one can be smarter than them and do the right thing (in my case make sure that the log file is actually group-writeable) but if this is the kind of suggestions they find proper to tell you, it’s no wonder what happened with Diaspora. So it’s one more reason why Rails shouldn’t be for the faint hearted and that you should pay a very good sysadmin if you want to run a Rails application.
Oh and by the way the cherry on top of this is that instead of just sending the log to stderr, leaving it to Passenger to wrangle – which would have worked out nicely if Passenger had a way to distinguish which app the errors are coming from – Rails also moves the log level to warning, just to spite you. And then tells you that it impacts performances! Ain’t that lovely?
Plan for the day? If I find some extra free time I’d like to give a try and package (not necessarily in this order) syslogger so that the whole production.log thing can go away fast.