Why does my rails app not deploy (H10 code error) and rails server not start?

Question

I am at the very start of a rails app with just a "hello world" page and the basic skeleton. i am trying to deploy to heroku before i start working on it. however, on both production and local server i can not get the app to start. I did have it start once on local host 3000 but now i changed something and it doesn work. the only things i changed were putting the sqlite gem into devlopment and pg gem into production since herku doesnt work with sqlite. please see following errors:

when trying to start the local server:

C:\Sites\nutri>rails s
C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/sqlite3-1.3.5-x86-mingw32/lib/sqlite3.rb:6:in `require': cannot load such file -- sqlite3/sqlite3_native (LoadError)
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/sqlite3-1.3.5-x86-mingw32/lib/sqlite3.rb:6:in `rescue in <top (required)>'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/sqlite3-1.3.5-x86-mingw32/lib/sqlite3.rb:2:in `<top (required)>'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/bundler-1.14.5/lib/bundler/runtime.rb:91:in `require'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/bundler-1.14.5/lib/bundler/runtime.rb:91:in `block (2 levels) in require'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/bundler-1.14.5/lib/bundler/runtime.rb:86:in `each'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/bundler-1.14.5/lib/bundler/runtime.rb:86:in `block in require'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/bundler-1.14.5/lib/bundler/runtime.rb:75:in `each'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/bundler-1.14.5/lib/bundler/runtime.rb:75:in `require'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/bundler-1.14.5/lib/bundler.rb:107:in `require'
        from C:/Sites/nutri/config/application.rb:7:in `<top (required)>'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:88:in `require'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:88:in `block in server'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:85:in `tap'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:85:in `server'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
        from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.6/lib/rails/commands.rb:18:in `<top (required)>'
        from bin/rails:4:in `require'
        from bin/rails:4:in `<main>'

when opening th eapp in production i get an H10 error, unfortunately herko suppor tpage doesnt go into any detail about how to fix this error and just states what the code means which i do not understand.

the heroku logs:

C:\Sites\nutri>heroku logs
This is the legacy Heroku CLI. Please install the new CLI from https://cli.heroku.com
2017-12-10T05:44:26.046591+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:319:in `build_app_and_options_from_config'
2017-12-10T05:44:26.046604+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:219:in `app'
2017-12-10T05:44:26.046616+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/server.rb:84:in `app'
2017-12-10T05:44:26.046628+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:354:in `wrapped_app'
2017-12-10T05:44:26.046639+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:283:in `start'
2017-12-10T05:44:26.046649+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/server.rb:104:in `start'
2017-12-10T05:44:26.046660+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:90:in `block in server'
2017-12-10T05:44:26.046670+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:85:in `tap'
2017-12-10T05:44:26.046680+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:85:in `server'
2017-12-10T05:44:26.046690+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
2017-12-10T05:44:26.046701+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands.rb:18:in `<top (required)>'
2017-12-10T05:44:26.046712+00:00 app[web.1]:    from bin/rails:4:in `require'
2017-12-10T05:44:26.046723+00:00 app[web.1]:    from bin/rails:4:in `<main>'
2017-12-10T05:44:26.239147+00:00 heroku[web.1]: State changed from starting to crashed
2017-12-10T05:44:32.729566+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=murmuring-woodland-44138.herokuapp.com request_id=49085526-9dfc-4fe7-abba-b11be446f965 fwd="82.102.17.248" dyno= connect= service= status=503 bytes= protocol=https
2017-12-10T05:45:15.010455+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=murmuring-woodland-44138.herokuapp.com request_id=e090f107-9036-4e55-9d70-8f450c4aa7a2 fwd="82.102.17.248" dyno= connect= service= status=503 bytes= protocol=https
2017-12-10T06:09:54.415945+00:00 heroku[web.1]: State changed from crashed to starting
2017-12-10T06:09:56.992085+00:00 heroku[web.1]: Starting process with command `bin/rails server -p 59932 -e production`
2017-12-10T06:10:00.485332+00:00 heroku[web.1]: State changed from starting to crashed
2017-12-10T06:10:00.375617+00:00 app[web.1]: => Booting Puma
2017-12-10T06:10:00.375631+00:00 app[web.1]: => Rails 5.0.6 application starting in production on http://0.0.0.0:59932
2017-12-10T06:10:00.375632+00:00 app[web.1]: => Run `rails server -h` for more startup options
2017-12-10T06:10:00.375633+00:00 app[web.1]: Exiting
2017-12-10T06:10:00.375723+00:00 app[web.1]: /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.6/lib/active_record/connection_adapters/connection_specification.rb:176:in `rescue in spec': Specified 'sqlite3' for database adapter, but the gem is not loaded. Add `gem 'sqlite3'` to your Gemfile (and ensure its version is at the minimum required by ActiveRecord). (Gem::LoadError)
2017-12-10T06:10:00.375747+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.6/lib/active_record/connection_adapters/connection_specification.rb:173:in `spec'
2017-12-10T06:10:00.375748+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.6/lib/active_record/connection_handling.rb:53:in `establish_connection'
2017-12-10T06:10:00.375751+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.6/lib/active_record/railtie.rb:125:in `block (2 levels) in <class:Railtie>'
2017-12-10T06:10:00.375752+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:69:in `instance_eval'
2017-12-10T06:10:00.375754+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:69:in `block in execute_hook'
2017-12-10T06:10:00.375775+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:60:in `with_execution_control'
2017-12-10T06:10:00.375776+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:65:in `execute_hook'
2017-12-10T06:10:00.375779+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:50:in `block in run_load_hooks'
2017-12-10T06:10:00.469714+00:00 heroku[web.1]: Process exited with status 1
2017-12-10T06:10:00.375780+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:49:in `each'
2017-12-10T06:10:00.375782+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:49:in `run_load_hooks'
2017-12-10T06:10:00.375783+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.6/lib/active_record/base.rb:324:in `<module:ActiveRecord>'
2017-12-10T06:10:00.375826+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.6/lib/active_record/base.rb:24:in `<top (required)>'
2017-12-10T06:10:00.375827+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `require'
2017-12-10T06:10:00.375828+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `block in require'
2017-12-10T06:10:00.375829+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:259:in `load_dependency'
2017-12-10T06:10:00.375830+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `require'
2017-12-10T06:10:00.375831+00:00 app[web.1]:    from /app/app/models/application_record.rb:1:in `<top (required)>'
2017-12-10T06:10:00.375832+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `require'
2017-12-10T06:10:00.375832+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `block in require'
2017-12-10T06:10:00.375833+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:259:in `load_dependency'
2017-12-10T06:10:00.375835+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:293:in `require'
2017-12-10T06:10:00.375836+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:380:in `block in require_or_load'
2017-12-10T06:10:00.375837+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:37:in `block in load_interlock'
2017-12-10T06:10:00.375838+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies/interlock.rb:12:in `block in loading'
2017-12-10T06:10:00.375839+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/concurrency/share_lock.rb:150:in `exclusive'
2017-12-10T06:10:00.375840+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies/interlock.rb:11:in `loading'
2017-12-10T06:10:00.375842+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:37:in `load_interlock'
2017-12-10T06:10:00.375865+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:358:in `require_or_load'
2017-12-10T06:10:00.375866+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:336:in `depend_on'
2017-12-10T06:10:00.375868+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.6/lib/active_support/dependencies.rb:252:in `require_dependency'
2017-12-10T06:10:00.375869+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/engine.rb:476:in `block (2 levels) in eager_load!'
2017-12-10T06:10:00.375871+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/engine.rb:475:in `each'
2017-12-10T06:10:00.375873+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/engine.rb:475:in `block in eager_load!'
2017-12-10T06:10:00.375891+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/engine.rb:473:in `each'
2017-12-10T06:10:00.375892+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/engine.rb:473:in `eager_load!'
2017-12-10T06:10:00.375893+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/engine.rb:354:in `eager_load!'
2017-12-10T06:10:00.375897+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/application/finisher.rb:59:in `block in <module:Finisher>'
2017-12-10T06:10:00.375896+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/application/finisher.rb:59:in `each'
2017-12-10T06:10:00.375901+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/initializable.rb:30:in `run'
2017-12-10T06:10:00.375899+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/initializable.rb:30:in `instance_exec'
2017-12-10T06:10:00.375920+00:00 app[web.1]:    from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
2017-12-10T06:10:00.375920+00:00 app[web.1]:    from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:228:in `block in tsort_each'
2017-12-10T06:10:00.375919+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/initializable.rb:55:in `block in run_initializers'
2017-12-10T06:10:00.375922+00:00 app[web.1]:    from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:431:in `each_strongly_connected_component_from'
2017-12-10T06:10:00.375923+00:00 app[web.1]:    from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:349:in `block in each_strongly_connected_component'
2017-12-10T06:10:00.375925+00:00 app[web.1]:    from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:347:in `each'
2017-12-10T06:10:00.375943+00:00 app[web.1]:    from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:347:in `call'
2017-12-10T06:10:00.375944+00:00 app[web.1]:    from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:347:in `each_strongly_connected_component'
2017-12-10T06:10:00.375945+00:00 app[web.1]:    from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:226:in `tsort_each'
2017-12-10T06:10:00.375947+00:00 app[web.1]:    from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:205:in `tsort_each'
2017-12-10T06:10:00.375948+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/initializable.rb:54:in `run_initializers'
2017-12-10T06:10:00.375965+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/application.rb:352:in `initialize!'
2017-12-10T06:10:00.375966+00:00 app[web.1]:    from /app/config/environment.rb:5:in `<top (required)>'
2017-12-10T06:10:00.375968+00:00 app[web.1]:    from /app/config.ru:3:in `require_relative'
2017-12-10T06:10:00.375980+00:00 app[web.1]:    from /app/config.ru:3:in `block in <main>'
2017-12-10T06:10:00.375982+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:55:in `instance_eval'
2017-12-10T06:10:00.375983+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:55:in `initialize'
2017-12-10T06:10:00.375990+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:319:in `build_app_and_options_from_config'
2017-12-10T06:10:00.375984+00:00 app[web.1]:    from /app/config.ru:in `new'
2017-12-10T06:10:00.375988+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:40:in `parse_file'
2017-12-10T06:10:00.375985+00:00 app[web.1]:    from /app/config.ru:in `<main>'
2017-12-10T06:10:00.375987+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:49:in `new_from_string'
2017-12-10T06:10:00.375985+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:49:in `eval'
2017-12-10T06:10:00.375992+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:219:in `app'
2017-12-10T06:10:00.376005+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:354:in `wrapped_app'
2017-12-10T06:10:00.376005+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/server.rb:84:in `app'
2017-12-10T06:10:00.376008+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/server.rb:104:in `start'
2017-12-10T06:10:00.376010+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:90:in `block in server'
2017-12-10T06:10:00.376006+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:283:in `start'
2017-12-10T06:10:00.376019+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:85:in `server'
2017-12-10T06:10:00.376012+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:85:in `tap'
2017-12-10T06:10:00.376021+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
2017-12-10T06:10:00.376027+00:00 app[web.1]:    from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.0.6/lib/rails/commands.rb:18:in `<top (required)>'
2017-12-10T06:10:00.376048+00:00 app[web.1]:    from bin/rails:4:in `<main>'
2017-12-10T06:10:00.376047+00:00 app[web.1]:    from bin/rails:4:in `require'
2017-12-10T06:27:43.466729+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=murmuring-woodland-44138.herokuapp.com request_id=b7646d82-6d59-45b2-8040-e16cf89d513a fwd="82.102.17.248" dyno= connect= service= status=503 bytes= protocol=https

C:\Sites\nutri>

notice particularly the last line:

2017-12-10T06:27:43.466729+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=murmuring-woodland-44138.herokuapp.com request_id=b7646d82-6d59-45b2-8040-e16cf89d513a fwd="82.102.17.248" dyno= connect= service= status=503 bytes= protocol=https

I have searched and read many similar questions on here, but none seem to have an answer to my particular case. any help much appreciated.

EDIT: added gem file:

source 'https://rubygems.org'

git_source(:github) do |repo_name|
  repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
  "https://github.com/#{repo_name}.git"
end


# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 5.0.6'
# Use sqlite3 as the database for Active Record
#gem 'sqlite3' #commented out see below
# Use Puma as the app server
gem 'puma', '~> 3.0'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.2'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby

# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
gem 'turbolinks', '~> 5'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.5'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '~> 3.0'
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development

group :development, :test do
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'sqlite3' #, '1.3.5'#added here because didnt deploy to heroku, as advised on https://gist.github.com/JennDudley/2493288
  gem 'byebug', platform: :mri
end

group :development do
  # Access an IRB console on exception pages or by using <%= console %> anywhere in the code.
  gem 'web-console', '>= 3.3.0'

end

group :production do
  gem 'pg'
  #gem 'rails_12factor'
end

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

EDIT 2, database.yml:

# SQLite version 3.x
#   gem install sqlite3
#
#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
#
default: &default
  adapter: sqlite3
  pool: 5
  timeout: 5000

development:
  <<: *default
  database: db/development.sqlite3

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: db/test.sqlite3

production:
  <<: *default
  database: db/production.sqlite3

EDIT 3: new config/datbase.yml file EDIT 4: new config/datbase.yml file (i accidentally added the wrong database yml file from another project, below is my database yml file)

# SQLite version 3.x
#   gem install sqlite3
#
#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
#
default: &default
  adapter: postgresql #sqlite3
  pool: 5
  timeout: 5000

# development:
#   <<: *default
#   database: db/development.sqlite3
development:
  <<: *default
  database: nutri_development

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
# test:
#   <<: *default
#   database: db/test.postgresql #sqlite3

test:
  <<: *default
  database: nutri_test

# production:
#   <<: *default
#   database: db/production.postgresql #sqlite3
production:
  <<: *default
  database: nutri_production
  prepared_statements: false
  encoding: unicode

# SQLite version 3.x
#   gem install sqlite3
#
#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
#
# default: &default
#   adapter: sqlite3
#   pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
#   timeout: 5000
# default: &default
#   adapter: postgresql
#   pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
#   timeout: 5000


# development:
#   <<: *default
#   database: db/development.sqlite3
# development:
#   <<: *default
# database: rails-tutorial_development #http://guides.rubyonrails.org/configuring.html#configuring-a-database

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.

# test:
#   <<: *default
#   database: db/test.sqlite3
# test:
#   <<: *default
#   database: rails-tutorial_development

# production:
#   <<: *default
#   database: db/production.sqlite3

# production:
#   <<: *default
#   adapter: postgresql
#   prepared_statements: false
#   encoding: unicode
#   database: rails-tutorial_development

is this the correct configuration to use postgresql?

Answer 1

See how in our default, you specify sqlite3 as the adapter?

default: &default
  adapter: sqlite3
  pool: 5
  timeout: 5000

Then, in your production, you use the defaults plus specify the sqlite3 database.

production:
  <<: *default
  database: db/production.sqlite3

Instead, it should look something like:

production:
  <<: *default
  adapter: postgresql
  encoding: unicode

Again, you really should set up postgresql on your development machine to avoid syntax differences between sqlite3 and postgresql.

To provision a database, go onto the Resources tab of your application on Heroku. Under 'Add-ons', search for 'Postgres'. Heroku will walk you through from there.

Once you're set up, in your terminal you'll need to run:

> heroku run rake db:migrate --app your_app_name

Or, if you'd rather load from your schema (which is the basically the result of all your migrations mashed into one file), you do something like:

> heroku run rake db:schema:load

REPLY

Here's what my database.yml looks like for one of my apps (naturally, I've substituted 'app_name' in for my actual app name):

default: &default
  adapter: postgresql
  encoding: unicode
  # For details on connection pooling, see rails configuration guide
  # http://guides.rubyonrails.org/configuring.html#database-pooling
  pool: 5

...

production:
  <<: *default
  database: app_name_production
  username: app_name_admin
  password: <%= ENV['APP_NAME_DATABASE_PASSWORD'] %>

As you can see, I in fact have database: and username: in my production section. username: may not be required, I'm not sure. According to SQLite on Heroku , you should include database: ... . But, as stated in the guide, it should be a custom name, not:

database: db/production.sqlite3

The encoding and pool bits come from section 3.15.3 (Configuring a PostreSQL Database) of the Rails Guide on Configuring a Database . You'll note that the Heroku guide does not specify encoding but the Rails guide does. I prioritize the Rails guide over the Heroku guide and so include it in all my database.yml files.

You already include pool and timeout in our default , so you don't need to reconfigure those in production .

"Set up postgreSQL on your development machine" means installing a postgreSQL server on your local machine. Simply including the pg gem does not install a server. You will ONLY need to do this if you decide to use postgreSQL in development (instead of sqlite). This has nothing to do with deploying to Heroku.

To learn more about installing postgresql on your machine, see the Local setup section of the Heroku Postgres guide.

You might also want to read the Dev/prod parity section of the Twelve-Factor App .

If you decide to continue developing with sqlite and deploying with postgresql, then you can completely ignore my comment about setting up postgresql on your development machine. However, as I said previously, sqlite and postgres have some subtle sytactic differences (the one I recall of the top of my head is how each of the databases implement LIKE functionality). What that means is that you could possibly have code that works flawlessly in development on sqlite but breaks in production on postgres. If you run into that situation, you will have to track down where the syntax differences are causing errors and then remediate your syntax. That is NO FUN.

Answer 2

Your local server error is due to file

from C:/Sites/nutri/config/application.rb:7:in '<top (required)>'

error is

C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/sqlite3-1.3.5-x86-
mingw32/lib/sqlite3.rb:6:in 'require': cannot load such file -- 
sqlite3/sqlite3_native (LoadError)

check if file sqlite3/sqlite3_native exists.

First try to deploy locally and think about Heroku.

Heroku server issue

2017-12-10T06:10:00.375723+00:00 app[web.1]: 
/app/vendor/bundle/ruby/2.3.0/gems/activerecord-
5.0.6/lib/active_record/connection_adapters/
connection_specification.rb:176:in `rescue in spec': Specified 
'sqlite3' for database adapter, but the gem is not loaded. Add `gem 
'sqlite3'` to your Gemfile (and ensure its version is at the minimum 
required by ActiveRecord). (Gem::LoadError)

says Gem compatibility issue between rails (ActiveRecord) and sqlite3 . Any reason you commented the version for sqlite3 ? try uncommenting it

gem 'sqlite3', '1.3.5'

Only certain version of rails works with sqlite3 versions

Also, can pg gem have a version like below

gem 'pg', '0.18.4'

Try all this, move your Gemfile.lock file

mv Gemfile.lock Gemfile.lock_

install gems now

bundle install