Naked Thought

Site down, SITE DOWN!

The website was down for a little bit today. Not the blog (♥ Tumblr), but our actual website which needs to be up so people can get in touch re: work (aside: we’re looking for work).

This is not ideal. So, what gives?

Well, we’re hosted on Heroku - which is great (we ♥ Heroku also). I thought this must be some sort of mistake, so I restarted the server:

$ heroku restart

This didn’t work (site still down), so I checked the logs to find out why:

$ heroku logs

This gave me a clue:

2011-10-10T23:59:53+00:00 heroku[web.1]: Starting process with command bundle exec rails server thin -p 20965 2011-10-11T00:00:54+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch 2011-10-11T00:00:54+00:00 heroku[web.1]: Stopping process with SIGKILL

Aha! The web process failed to bind to the port! Gotcha. But what does that mean? No idea. A 20 second Google later and I have the answer (the Heroku documentation is great):

A web process took longer than 60 seconds to bind to its assigned $PORT. This error is often caused by a process being unable to reach an external resource, such as a database.

So the app can’t reach the database. Interesting. A bit of background: our website is currently static (i.e. no database). As we’re planning on using one in future for client logins etc., I had added the mongoid gem to the Gemfile in anticipation of such a system. In addition, I had also added the mongohq:free add-on to our Heroku app. This was working for about a month without issue, so what gives?

To find out I logged into Heroku, navigated to our app, clicked the “Add-Ons” drop-down menu and clicked on MongoHQ. This should take me to the remote admin console to manage the database. However, it redirected me to the MongoHQ homepage. Hmmm, interesting. As there was nothing in that database anyway, I decided to go for the quick fix - remove & re-add the add-on:

$ heroku addons:remove mongohq:free $ heroku addons:add mongohq:free

Heroku found some issue with re-adding mongohq:free:

——-> Adding mongohq:free to nakedapps… failed  ! Could not create resource with vendor, please try again later

So I re-added it from the heroku.com GUI Instead (Add-Ons > MongoHQ Learn More > Add Free). This yielded no error, so I thought I was all good. Onwards with the restart:

$ heroku restart

App still not working. Still getting a redirect to the MongoHQ website. Now if you are in the same bucket as I was and are hoping that I’ve got the solution to this problem for you right here, I apologise. I don’t know why this was broken, but I’ve got a theory:

Perhaps MongoHQ lets you spawn a free instance, and if you use it - great! It lets you keep it. However, if you spawn a free instance and don’t use it within a reasonable amount of time, maybe it does the smart thing and destroys it. This would explain the redirect, and why the app couldn’t connect - no database.

So where to from here? Well, as I had eluded to previously, there’s actually no current need for a database. We just wanted the website back up. So I did some looking around for how to remove the database dependency. I found a couple of solutions. This article sums things up nicely for both Rails 2 and Rails 3 apps. As the app is running Rails 3.1, I had to change the config/application.rb file from this:

require "rails/all"

To this:

require "action_controller/railtie"
require "action_mailer/railtie"
require "active_resource/railtie"
require "rails/test_unit/railtie"

As I was running Mongoid, I had already done this - and as we know, the app was still not working. So I tried a couple more things. I commented out this line in mongoid.yml:

# uri: <%= ENV['MONGOHQ_URL'] %>

And did a push to heroku:

$ git commit -am “commented out mongo URL” $ git push heroku master

Still not working. A little more Googling and I found a hint at the solution - comment out the gems in the Gemfile. So out went:

#  gem 'mongoid', '>= 2.0.1'
#  gem 'bson_ext', '>= 1.3.0'
#  gem 'pg'

Another commit, push & restart. This time a different error, so I checked the logs:

2011-10-11T02:58:26+00:00 app[web.1]: ActionView::Template::Error (modernizr.js isn’t precompiled)

I’m using the modernizr-rails gem to provide html5 compatibility for older browsers, and it isn’t precompiled. It’s working locally, but Heroku is complaining. Apparently it needs to be precompiled. How do we do this? Add the following line to config/application.rb:

config.assets.precompile += %w( modernizr.js )

One more commit, push & restart. Everything is working once more!

Hope this helps someone.

B.