How can you block or filter IP addresses on Heroku?

Question

Is there a way to implement IP filtering or IP access rules much like I would with nginx/apache to restrict or block certain IPs on Heroku?

Note: I know this can be done from within my application (Rails 3.2) very easily but I don't think this is the most efficient use of my resources on Heroku. Also, a Rack based solution would be better than implementing the filtering in Rails.

Answer 1

I added 'rack-block' as Rack middleware. In config/initializers, add a new file:

YourApp::Application.configure do

  config.middleware.insert_before(Rack::Lock, Rack::Block) do  
    # Add your rules with the rack-block syntax in here
  end

end

Works like a charm.

Answer 2

You should check out rack-attack. Looks like it does the same as rack-block, but is much more widely used and updated frequently. To block a specific IP you can do this:

# Block requests from 1.2.3.4
Rack::Attack.blacklist('block 1.2.3.4') do |req|
  # Requests are blocked if the return value is truthy
  '1.2.3.4' == req.ip
end