Puma: LoadError: cannot load such file -- etc

[gvpmahesh]

Steps to reproduce

1) in dockerfile use apline 3.8 as base image

2) I had this line in dockerfile,RUN bundle exec rake hello:world --trace

Expected behavior

In alpine 3.7 it just works fine, where ruby version is 2.4.5-r0. Rails version is 5.1.2 and puma is 3.12.0

RUN bundle exec rake hello:world --trace
 ---> Running in 357d4f930bab
** Invoke hello:world (first_time)
** Invoke environment (first_time)
** Execute environment
No executable found at /usr/local/bin/wkhtmltopdf. Will fall back to /app/vendor/bundle/ruby/2.4.0/bin/wkhtmltopdf
** Execute hello:world
hello world

Actual behavior

rake aborted!
LoadError: cannot load such file -- etc
/app/vendor/bundle/ruby/2.5.0/gems/puma-3.12.0/lib/puma.rb:5:in `require'
/app/vendor/bundle/ruby/2.5.0/gems/puma-3.12.0/lib/puma.rb:5:in `<top (required)>'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/runtime.rb:81:in `require'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/runtime.rb:81:in `block (2 levels) in require'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/runtime.rb:76:in `each'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/runtime.rb:76:in `block in require'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/runtime.rb:65:in `each'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/runtime.rb:65:in `require'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler.rb:114:in `require'
/app/config/application.rb:19:in `<top (required)>'
/app/Rakefile:4:in `require_relative'
/app/Rakefile:4:in `<top (required)>'
/app/vendor/bundle/ruby/2.5.0/gems/rake-12.3.2/lib/rake/rake_module.rb:29:in `load'
/app/vendor/bundle/ruby/2.5.0/gems/rake-12.3.2/lib/rake/rake_module.rb:29:in `load_rakefile'
/app/vendor/bundle/ruby/2.5.0/gems/rake-12.3.2/lib/rake/application.rb:703:in `raw_load_rakefile'
/app/vendor/bundle/ruby/2.5.0/gems/rake-12.3.2/lib/rake/application.rb:104:in `block in load_rakefile'
/app/vendor/bundle/ruby/2.5.0/gems/rake-12.3.2/lib/rake/application.rb:186:in `standard_exception_handling'
/app/vendor/bundle/ruby/2.5.0/gems/rake-12.3.2/lib/rake/application.rb:103:in `load_rakefile'
/app/vendor/bundle/ruby/2.5.0/gems/rake-12.3.2/lib/rake/application.rb:82:in `block in run'
/app/vendor/bundle/ruby/2.5.0/gems/rake-12.3.2/lib/rake/application.rb:186:in `standard_exception_handling'
/app/vendor/bundle/ruby/2.5.0/gems/rake-12.3.2/lib/rake/application.rb:80:in `run'
/app/vendor/bundle/ruby/2.5.0/gems/rake-12.3.2/exe/rake:27:in `<top (required)>'
/app/vendor/bundle/ruby/2.5.0/bin/rake:23:in `load'
/app/vendor/bundle/ruby/2.5.0/bin/rake:23:in `<top (required)>'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/cli/exec.rb:74:in `load'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/cli/exec.rb:74:in `kernel_load'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/cli/exec.rb:28:in `run'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/cli.rb:463:in `exec'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor/invocation.rb:126:in `invoke_command'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor.rb:387:in `dispatch'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/cli.rb:27:in `dispatch'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor/base.rb:466:in `start'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/cli.rb:18:in `start'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/exe/bundle:30:in `block in <top (required)>'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/lib/bundler/friendly_errors.rb:124:in `with_friendly_errors'
/usr/lib/ruby/gems/2.5.0/gems/bundler-1.17.3/exe/bundle:22:in `<top (required)>'
/usr/bin/bundle:23:in `load'
/usr/bin/bundle:23:in `<main>'
The command '/bin/sh -c bundle exec rake hello:world --trace' returned a non-zero code: 1

System configuration

Ruby version: 2.5.2-r0
Rails version: 5.1.2
Puma version: 3.12.0
Alpine: 3.8

[evanphx]

Your ruby install is broken, the etc standard library module is missing.

[joshk0]

For those coming here with a similar problem, just make sure to apk add ruby-etc in your Dockerfile.

[hakatashi]

You can also use apk install ruby-full to install ruby with all standard libraries to reduce these kinds of annoying errors.

[Nakilon]

Probably you both wanted to say apk add, not apk install.