CODEWITHSUNDEEP
rubydockersinatragoogle-cloud-run
bonafernando
bonafernando

Reputation: 1159

How to fix Docker using the wrong Ruby path on Alpine

I have a very simple container running Sinatra in a Google Cloud Run. With no changes in the Dockerfile it recently stopped working.

When I try to run it I get the error:

/usr/local/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require': cannot load such file -- sinatra (LoadError)
    from /usr/local/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from main_wow.rb:1:in `<main>'

Dockerfile:

FROM ruby:2.6.4-alpine3.9

ENV APP_HOME /WOW

WORKDIR $APP_HOME

ADD Gemfile* $APP_HOME/

RUN gem install bundler
RUN bundle install

ADD main_wow.rb $APP_HOME
ADD views/ $APP_HOME/views

# Start server
ENV PORT 3000
EXPOSE 3000
CMD ["ruby", "main_wow.rb"]

Gemfile:

source "http://rubygems.org"

gem 'sinatra'
gem 'i18n'

First 10 lines of main_wow.rb:

require "sinatra"
require "net/http"
require "json"
require "i18n"
I18n.config.available_locales = :en

configure do
  set :public_folder, './views'
  set :bind, '0.0.0.0'
end

From what I could understand, it's trying to fetch the ruby gems from the major version 2.6.0, instead of 2.6.4. I have already tried to create a link, to set ruby version on the Gemfile but none seems to work...

Upvotes: 2

Views: 1416

Answers (1)

bonafernando
bonafernando

Reputation: 1159

After several guesses, I fixed it with bundle exec on the last line of the Dockerfile:

CMD ["bundle", "exec", "ruby", "main_wow.rb"]

Upvotes: 1

Related Questions