Question

I’m setting up Ruby on Rails for the first time; on my server, I’ve created and loaded the default rails app. I can view the default page (“Welcome aboard! You are riding Rails”), but when I go to click on the link to “View Application Environment”, it generates a 500 error.

(You can view it here.)

I’d like to know more about the error, but, the log file (“log/production.log”) is empty. Looking at my Apache log I find:

Rails Error: Unable to access log file. Please ensure that
/var/www/rails/myapp/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.

So, I actually want to get my Ruby on Rails error logging working.

I know this problem has been posted a few times before, but I tried everything I could find, so here’s what I have tried:

1. Created the “log/production.log” file, set the owner to www-data, set chmod 0666.
2. Set the owner of the “log” folder to www-data, set chmod 0666.
3. Double-checked my production environment settings such that config.log_level = :info is set.

4. Checked that Apache is using the www-data user (“etc/apache2/envvars”):

   export APACHE_RUN_USER=www-data
   export APACHE_RUN_GROUP=www-data
   

5. “etc/apache2/mods-available/passenger.conf” has a default user set for Passenger:

   <IfModule mod_passenger.c>
     PassengerRoot /usr
     PassengerRuby /usr/bin/ruby
     PassengerDefaultUser www-data
   </IfModule>
   

6. The owner of “config.ru” and “configs/environment.rb” is www-data

7. My virtual host has been set accordingly:

   DocumentRoot /var/www/rails/myapp/public
   RackBaseURI /
   RackEnv production
   PassengerMaxPoolSize 4
   

Already read and attempted all the fixes suggested in these places:

• Rails: Unable to access log file
• Can't access log files in production
• http://railsforum.com/viewtopic.php?id=36168
• Why am I getting Permission denied error in deployment on files generated by capistrano?
• http://bradhe.wordpress.com/2011/06/26/a-sneaky-rails-3-bug-in-logging/

(That’s all I can remember trying right now…)

Some environment settings of mine:

• Ubuntu 11.10 running on Amazon EC2
• Apache 2.2.20
• RVM 1.10.2
• Ruby 1.9.3p0
• Rails 3.1.3

Answer 1

This issue is resolved now, though the the cause of the problem itself isn’t entirely clear.

I had some weird configuration issues with Apache & Passenger (a.k.a. ModRails). Two modules existed: one that appeared to come packaged with Apache(?) and one I obtained via passenger-install-apache2-module. When I pointed to the pre-installed one, I had this logging issue. When I pointed to the one deployed by passenger-install-apache2-module, I had a completely different issue where Passenger would crash with a segfault (see my post on ServerFault here.)

In the end, I completely wiped my server and performed a clean install of everything from the base Ubuntu AMI (running on Amazon EC2 made this easy enough.) Upon reinstalling, I ran passenger-install-apache2-module and configured Apache to load the module deployed by it. This time, the module didn’t crash, but the log error appeared. I set chmod 755 on the root of my Rails application, made sure the production.log existed and that it had at least chmod 0666 privileges. And voila, problem gone.

TL;DR Did a fresh install, made sure I was using the latest Passenger module, and my file permissions were set properly.