rails app deployed to heroku but still giving application error when launching site in a browser. why?

Question

i have no idea why my site is showing an "Applicaiton Error" i dont see any problems in my log. I have followed the steps specified in the heroku site to add a "pg" gem and run rake db:create and rake db:migrate but even though the applicaiton runs fine on my localhost i keep getting an error when pushing to heroku. here is my log from heroku:

-----> Ruby app detected
-----> Compiling Ruby/Rails
-----> Using Ruby version: ruby-2.0.0
-----> Warning:
       Removing `Gemfile.lock` because it was generated on Windows.
       Bundler will do a full resolve so native gems are handled properly.
       This may result in unexpected gem versions being used in your app.
       In rare occasions Bundler may not be able to resolve your dependencies at all.
       https://devcenter.heroku.com/articles/bundler-windows-gemfile
-----> Installing dependencies using 1.5.2
       Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin -j4
       Fetching gem metadata from https://rubygems.org/.........
       Fetching additional metadata from https://rubygems.org/..
       Resolving dependencies...
       Using i18n (0.6.9)
       Using minitest (4.7.5)
       Using multi_json (1.9.2)
       Using thread_safe (0.3.3)
       Using tzinfo (0.3.39)
       Using builder (3.1.4)
       Using rake (10.2.2)
       Using erubis (2.7.0)
       Using mime-types (1.25.1)
       Using rack (1.5.2)
       Using polyglot (0.3.4)
       Using activerecord-deprecated_finders (1.0.3)
       Using arel (4.0.2)
       Using bcrypt (3.1.7)
       Using sass (3.2.19)
       Using bundler (1.5.2)
       Using json (1.8.1)
       Using coffee-script-source (1.7.0)
       Using certified (0.1.1)
       Using thor (0.19.1)
       Using execjs (2.0.2)
       Using multipart-post (2.0.0)
       Using orm_adapter (0.5.0)
       Using tilt (1.4.1)
       Using geocoder (1.1.9)
       Using gmaps4rails (2.1.2)
       Using hike (1.2.3)
       Using multi_xml (0.5.5)
       Using hashie (2.1.1)
       Using subexec (0.2.3)
       Using oauth (0.4.7)
       Using pg (0.17.1)
       Using simple-image-uploader (0.1.5)
       Using jwt (0.1.11)
       Using activesupport (4.0.2)
       Using rack-test (0.6.2)
       Using warden (1.2.3)
       Using treetop (1.4.15)
       Using bootstrap-sass (3.1.1.0)
       Using coffee-script (2.2.0)
       Using uglifier (2.5.0)
       Using faraday (0.9.0)
       Using omniauth (1.2.1)
       Using sprockets (2.11.0)
       Using mini_magick (3.7.0)
       Using actionpack (4.0.2)
       Using jbuilder (1.5.3)
       Using activemodel (4.0.2)
       Using mail (2.5.4)
       Using oauth2 (0.9.3)
       Using omniauth-oauth (1.0.1)
       Using railties (4.0.2)
       Using sprockets-rails (2.0.1)
       Using shareable (0.0.3)
       Using activerecord (4.0.2)
       Using carrierwave (0.10.0)
       Using omniauth-oauth2 (1.1.2)
       Using omniauth-twitter (1.0.1)
       Using actionmailer (4.0.2)
       Using coffee-rails (4.0.1)
       Using devise (3.2.4)
       Using foundation-rails (5.2.2.0)
       Using jquery-rails (3.1.0)
       Using sass-rails (4.0.3)
       Using omniauth-facebook (1.6.0)
       Using omniauth-google-oauth2 (0.2.2)
       Using rails (4.0.2)
       Using turbolinks (2.2.2)
       Using figaro (0.7.0)
       Installing rails_serve_static_assets (0.0.2)
       Installing rails_stdout_logging (0.0.3)
       Installing rails_12factor (0.0.2)
       Your bundle is complete!
       Gems in the groups development and test were not installed.
       It was installed into ./vendor/bundle
       Bundle completed (16.55s)
       Cleaning up the bundler cache.
-----> Writing config/database.yml to read from DATABASE_URL
-----> Preparing app for Rails asset pipeline
       Running: rake assets:precompile
       Asset precompilation completed (4.79s)
       Cleaning assets
       Running: rake assets:clean
-----> WARNINGS:
       Removing `Gemfile.lock` because it was generated on Windows.
       Bundler will do a full resolve so native gems are handled properly.
       This may result in unexpected gem versions being used in your app.
       In rare occasions Bundler may not be able to resolve your dependencies at all.
       https://devcenter.heroku.com/articles/bundler-windows-gemfile

       No Procfile detected, using the default web server (webrick)
       https://devcenter.heroku.com/articles/ruby-default-web-server
-----> Discovering process types
       Procfile declares types -> (none)
       Default types for Ruby  -> console, rake, web, worker

-----> Compressing... done, 107.3MB
-----> Launching... done, v7
       http://protected-springs-8562.herokuapp.com/ deployed to Heroku

Try installing addons like Papertrail and Airbrake, they will help you a lot in understanding what's happening on Heroku. — aledalgrande
Have you run heroku run rake db:migrate to create the db tables on heroku? Running heroku logs will also allow you to look at the log files. — andreofthecape

Jon Mountjoy Jon Mountjoy · Accepted Answer · 2014-04-15T13:53:17

How about showing some logs? What do you get when you run heroku logs?

I'm going to guess that you haven't spun up a web dyno, so nothing is actually running.

Try heroku ps and let us know what's there.

If nothing is running, try running something with heroku ps:scale web=1

PS. Don't use the default webrick web server in production.

rails app deployed to heroku but still giving application error when launching site in a browser. why?

1 Answers