It has some errors when run it. in docker.

[doeasier]

The error like this:

docker logs f09d

bundler: failed to load command: rackup (/usr/local/bundle/bin/rackup)
Errno::ENOENT: No such file or directory @ rb_sysopen - config.yml
/usr/local/lib/ruby/2.5.0/psych.rb:497:in initialize' /usr/local/lib/ruby/2.5.0/psych.rb:497:in open'
/usr/local/lib/ruby/2.5.0/psych.rb:497:in load_file' /pg_web_stats/lib/pg_web_stats.rb:9:in initialize'
/pg_web_stats/setup.rb:4:in new' /pg_web_stats/setup.rb:4:in <top (required)>'
/pg_web_stats/config.ru:1:in require' /pg_web_stats/config.ru:1:in block in

'
/usr/local/bundle/gems/rack-2.0.4/lib/rack/builder.rb:55:in instance_eval' /usr/local/bundle/gems/rack-2.0.4/lib/rack/builder.rb:55:in initialize'
/pg_web_stats/config.ru:in new' /pg_web_stats/config.ru:in '
/usr/local/bundle/gems/rack-2.0.4/lib/rack/builder.rb:49:in eval' /usr/local/bundle/gems/rack-2.0.4/lib/rack/builder.rb:49:in new_from_string'
/usr/local/bundle/gems/rack-2.0.4/lib/rack/builder.rb:40:in parse_file' /usr/local/bundle/gems/rack-2.0.4/lib/rack/server.rb:319:in build_app_and_options_from_config'
/usr/local/bundle/gems/rack-2.0.4/lib/rack/server.rb:219:in app' /usr/local/bundle/gems/rack-2.0.4/lib/rack/server.rb:354:in wrapped_app'
/usr/local/bundle/gems/rack-2.0.4/lib/rack/server.rb:283:in start' /usr/local/bundle/gems/rack-2.0.4/lib/rack/server.rb:148:in start'
/usr/local/bundle/gems/rack-2.0.4/bin/rackup:4:in <top (required)>' /usr/local/bundle/bin/rackup:23:in load'
/usr/local/bundle/bin/rackup:23:in <top (required)>

I'm already to change config.yml.example to config.yml at the path "root" and "spec".
I'm not a programer of ruby, so how can it run in docker?