Category Archives: Ruby on Rails

WARN Could not determine content-length of response body – Ruby on Rails

Hey everyone

I was going through my development logs today and noticed that the following line was appearing everywhere:

WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

While nothing appeared to be wrong, it made the logs a lot harder to read. A stackoverflow post indicates that this is a webrick issue that can be avoided by switching to thin. This is also the recommended option for heroku. In order to use thin, you simply need to add it to your Gemfile:


#Added gems
gem 'therubyracer' #JavaScript
gem 'thin' #Instead of webrick

Run bundle install

chris@chris-VirtualBox:~/calendar$ bundle install
Fetching gem metadata from
Fetching gem metadata from
Using rake (10.0.2) 
Using i18n (0.6.1) 
Using multi_json (1.4.0) 
Using activesupport (3.2.9) 
Using builder (3.0.4) 
Using activemodel (3.2.9) 
Using erubis (2.7.0) 
Using journey (1.0.4) 
Using rack (1.4.1) 
Using rack-cache (1.2) 
Using rack-test (0.6.2) 
Using hike (1.2.1) 
Using tilt (1.3.3) 
Using sprockets (2.2.2) 
Using actionpack (3.2.9) 
Using mime-types (1.19) 
Using polyglot (0.3.3) 
Using treetop (1.4.12) 
Using mail (2.4.4) 
Using actionmailer (3.2.9) 
Using arel (3.0.2) 
Using tzinfo (0.3.35) 
Using activerecord (3.2.9) 
Using activeresource (3.2.9) 
Using bcrypt-ruby (3.0.1) 
Using bundler (1.2.3) 
Using coffee-script-source (1.4.0) 
Using execjs (1.4.0) 
Using coffee-script (2.2.0) 
Using rack-ssl (1.3.2) 
Using json (1.7.5) 
Using rdoc (3.12) 
Using thor (0.16.0) 
Using railties (3.2.9) 
Using coffee-rails (3.2.2) 
Installing daemons (1.1.9) 
Installing eventmachine (1.0.0) with native extensions 
Using jquery-rails (2.1.4) 
Using libv8 ( 
Using pg (0.14.1) 
Using rails (3.2.9) 
Using sass (3.2.3) 
Using sass-rails (3.2.5) 
Using therubyracer (0.10.2) 
Installing thin (1.5.0) with native extensions 
Using uglifier (1.3.0) 
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.

And finally start thin:

chris@chris-VirtualBox:~/calendar$ rails s thin
=> Booting Thin
=> Rails 3.2.9 application starting in development on
=> Call with -d to detach
=> Ctrl-C to shutdown server
>> Thin web server (v1.5.0 codename Knife)
>> Maximum connections set to 1024
>> Listening on, CTRL+C to stop

If you’d prefer to keep using Webrick, the following patch is said to resolve the issue:

The Name is Either Already Used or Reserved by Ruby on Rails

Hey everyone,

I ran into the following error while attempting to create a new model called calendar today:

chris@chris-VirtualBox:~/calendar$ rails g model calendar
      invoke  active_record
      The name 'Calendar' is either already used in your application or reserved by Ruby on Rails. Please choose an alternative and run this generator again.

It turns out that this was due to the fact that my application was also called Calendar. In order to get around this I decided to rename the application. This required a little bit of searching and thanks to this Stackoverflow post I found references in the following files:

– config/application.rb
– config/environment.rb
– config/environments/development.rb
– config/environments/production.rb
– config/environments/test.rb
– config/initializers/secret_token.rb
– config/initializers/session_store.rb
– config/mongoid.yml (if using Mongoid)
– config/routes.rb
– Rakefile
– app/views/layouts/application.html.erb, in title tag
– initializers/secret_token.rb
– initializers/session_store.rb

Let me know if you find any more spots that I’ve missed!

Paypal_Adaptive IPN Verification: INVALID – Ruby on Rails

Hey everyone,

I’ve been working with the PayPal_Adaptive gem recently and unfortunately I’ve run into a few issues. The latest of these has been that that my IPN verification was returning an INVALID response from Paypal.

I had made a few modifications to the provided payment_notification.rb file in order to accommodate for a few app specific requirements. This left me having to pass the original data attribute params. Unfortunately this wasn’t identical to the response that PayPal expected, I actually needed to use the following:

#Incorrect usage

#Correct usage

I realised this error after reading Tanel’s post about securing your IPN interactions so make sure you check out his blog if you run into any more problems!


OpenSSL::PKey::RSAError Neither PUB key nor PRIV key:: nested asn1 error – Adaptive Payments Gem

Hey everyone,

I’ve been mucking around with PayPal for a while and decided to try out the adaptive_payments gem by Tommy Chheng. Unfortunately I ran into the following error:


Neither PUB key nor PRIV key:: nested asn1 error

It turns out that I’d simply skipped an important part of the readme file. The api_cert_file in the paypal_adaptive.yaml file should point to a file containing BOTH your paypal_cert_pem.txt and whatever your private key happens to be. This took an embarrassingly long time for me to figure out, so hopefully this will help some of you!

It turns out I still had this wrong, I was using the wrong certs. After sorting out a few more errors that I ran into after the one mentioned above I finally started getting a response from Paypal, unfortunately it was another error message:

Authentication failed. API credentials are incorrect

It turns out I was using the wrong certs. If you’ve run into the same problem you’ll need to go to Profile > Request API Credentials > Option 2 (Request API credentials to create your own API username and password.). Then download the cert and point to this.

Hey everyone, just another update to this. If you happened to be following the railscast on PayPal before attempting to use the gem, you may not get the option to download the certs mentioned above. To get around this, simply remove your existing certificates (Profile > API Access > Option 2 > Remove > Remove). You should now see the ‘Request API Certificate Option’.

Sorry about the confusing post, but there’s a *slight* chance it might be able to help someone else who runs into the same problem.


Hey everyone,

I’ve just done a fresh install of RVM using the guide below. There were a few dependencies missing, but other than that it all went pretty smoothly.


Next time I do an install I’ll try to document the whole thing, but for now that link is probably one of the better/simpler guides I’ve come across. If you have any problems please leave a comment below and I’ll try to get back to you.


Just another guide I’ve come across that seems to work well, this one is a complete “start to finish” one:

Heroku Timezones – Ruby on Rails

Hey everyone,

Just a quick post on how to adjust the timezone on Heroku, comes in handy when using the log files.

$ heroku config:add TZ=Australia/Brisbane

There is a fairly detailed StackOverflow post at the following link if anyone is interested in more info:

The language options can also be found on the following wikipedia page:

Rails Casts #142 Paypal Notifications

Hey all,

I ran into a bit of an issue in Rails Cast #142. I received the following error while testing the IPN:

WARNING: Can't verify CSRF token authenticity
Completed 500 Internal Server Error in 2ms
app/controllers/payment_notifications_controller.rb:11:in `process_ipn_payment'

Simply replace the following line with the alternative below it:

protect_from_forgery :except => [:create]
skip_before_filter :verify_authenticity_token, :only => [:create]

Cannot Generate Tempfile – Ruby on Rails

Ran into the following problem, still not too sure what caused it but this seems to have fixed it:


cannot generate tempfile `/home/chris/cartsite/tmp/cache/assets/sprockets%2Fd585a06e2ee6203ccb04c8b84150d14d20120804-8682-7q77nb-9'

Just run the following:

$ rake tmp:clear

Let me know if you come across the cause, I’d be interested to know.

Paypal Platform Ruby SDK – Adaptive Payments

Hey everyone,

This is the SDK for PayPal adaptive payments. I’ve just uploaded it to *hopefully* make it a little easier to find. Please note that it has not been updated recently and that there are a few changes to be made. The StackOverflow post below provides a few examples:

StackOverflow Post:
Adaptive Payments with Ruby

I’ll try to list any others as I come across them, but if you’ve got some of your own please let me know and I’ll try to keep the post up to date.

Download SDK here:
Paypal Platform SDK

Error #1:

Internal Server Error

undefined method `debug_rjs=' for ActionView::Base:Class

Remove the following line from your development.rb config file:

PayPalPlatformRubySDK::Application.configure do
  # Settings specified here will take precedence over those in config/environment.rb

  # In the development environment your application's code is reloaded on
  # every request.  This slows down response time but is perfect for development
  # since you don't have to restart the webserver when you make code changes.
  config.cache_classes = false

  # Log error messages when you accidentally call methods on nil.
  config.whiny_nils = true

  # Show full error reports and disable caching
  config.consider_all_requests_local       = true
  #config.action_view.debug_rjs             = true <---- Comment this line out (no longer supported)
  config.action_controller.perform_caching = false

  # Don't care if the mailer can't send
  config.action_mailer.raise_delivery_errors = false

  # Print deprecation notices to the Rails logger
  config.active_support.deprecation = :log

  # Only use best-standards-support built into browsers
  config.action_dispatch.best_standards_support = :builtin

Paypal IPN History:
For some reason the IPN history button often won’t appear in the sandbox, use the following link to view it:

IPN Notifications:
Just a warning for anyone else setting up payments with PayPal, the sandbox IPN is extremely flaky. It has gone down twice in the last six months for weeks at a time, with no warning or error messages. If you’re not receiving the IPN check out the forums to make sure it’s not down.