Getting Heroku h10 error when it works locally - ruby-on-rails

Question

Currently I am getting a h10 app crashed error even though it works locally and the logs do not seem very helpful. The log first has the error
Error R10 (Boot timeout) -> Web process failed to bind to $PORT within
60 seconds of launch before getting the error at=error code=H10
desc="App crashed" method=GET path="/favicon.ico"
host=maitri-compassionate-care-app.herokuapp.com
request_id=602ed7f2-118f-43b2-b57f-077b89c7b2c4 fwd="98.248.251.49"
dyno= connect= service= status=503 bytes=
Here is the log:
2016-04-29T01:44:39.917289+00:00 heroku[slug-compiler]: Slug compilation started
2016-04-29T01:44:39.917299+00:00 heroku[slug-compiler]: Slug compilation finished
2016-04-29T01:44:41.023311+00:00 heroku[web.1]: State changed from crashed to starting
2016-04-29T01:44:43.205739+00:00 heroku[web.1]: Starting process with command `bundle exec rails s`
2016-04-29T01:44:46.498256+00:00 app[web.1]: DEPRECATION WARNING: The configuration option `config.serve_static_assets` has been renamed to `config.serve_static_files` to clarify its role (it merely enables serving everything in the `public` folder and is unrelated to the asset pipeline). The `serve_static_assets` alias will be removed in Rails 5.0. Please migrate your configuration files accordingly. (called from block in <top (required)> at /app/config/environments/production.rb:2)
2016-04-29T01:44:46.880147+00:00 app[web.1]: [2016-04-29 01:44:46] INFO WEBrick 1.3.1
2016-04-29T01:44:46.880438+00:00 app[web.1]: [2016-04-29 01:44:46] INFO WEBrick::HTTPServer#start: pid=3 port=3000
2016-04-29T01:44:46.880180+00:00 app[web.1]: [2016-04-29 01:44:46] INFO ruby 2.2.2 (2015-04-13) [x86_64-linux]
2016-04-29T01:45:43.548293+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch
2016-04-29T01:45:43.548293+00:00 heroku[web.1]: Stopping process with SIGKILL
2016-04-29T01:45:44.291920+00:00 heroku[web.1]: Process exited with status 137
2016-04-29T01:45:44.312346+00:00 heroku[web.1]: State changed from starting to crashed
2016-04-29T01:45:48.319822+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=maitri-compassionate-care-app.herokuapp.com request_id=242958be-0403-4b41-aec9-c2d1603630a2 fwd="98.248.251.49" dyno= connect= service= status=503 bytes=
2016-04-29T01:45:48.178954+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=maitri-compassionate-care-app.herokuapp.com request_id=ae7f2a3a-d65e-4829-84b6-74c178e2973d fwd="98.248.251.49" dyno= connect= service= status=503 bytes=
2016-04-29T01:45:49.055039+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=maitri-compassionate-care-app.herokuapp.com request_id=602ed7f2-118f-43b2-b57f-077b89c7b2c4 fwd="98.248.251.49" dyno= connect= service= status=503 bytes=
I have tried heroku restart, heroku ps restart, and rake rails update bin but none of them seem to help. I am not sure how to get a more specific error besides just a timeout and a crash.
Thanks

Answer 1

It looks like your app is using WEBrick as the web server. This is fine for a local development environment, but it shouldn't be used in a production environment such as when deployed to Heroku.
Heroku recommends using puma as the production server. Detailed instructions can be found in their dev center documentation.
https://devcenter.heroku.com/articles/deploying-rails-applications-with-the-puma-web-server

Answer 2

From Heroku docs:
In the Common Runtime, a web dyno must bind to its assigned $PORT within 60 seconds of startup. If it doesn’t, it is terminated by the dyno manager and a R10 Boot Timeout error is logged. Processes can bind to other ports before and after binding to $PORT.
According to your logs, WEBrick is running on port 3000 instead of $PORT, leaving $PORT unbound to trip the 60-second timeout. WEBrick must be configured to start on the Heroku-assigned port $PORT. You can do that with a Procfile.
Create a Procfile, named exactly that, with the following line:
web: bundle exec rails server -p $PORT
Then (from the docs):
For Heroku to use your Procfile, add the Procfile to the root directory of your application, then push to Heroku:
$ git add .
$ git commit -m "Procfile"
$ git push heroku