\n<\/iframe>\n<\/div><\/figure>\n\n\n\nAs I'm writing, Rails <code>v7.0.3<\/code> with Ruby <code>3.1.2<\/code> is current. Yet this book is based on <code>Rails v5.2.2<\/code> and <code>Ruby 2.6<\/code>.<\/p>\n\n\n\nDocker makes these kind of version changes super easy. I recommend just sticking with exactly what the book uses and explicitly setting:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gem install rails -v 5.2.2<\/code><\/pre>\n\n\n\nIf you keep rails on v5.2.2 then all of the rest of the instructions should work, and when you start the rails server with:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>docker run -p 3000:3000 ${my-image-id} bin\/rails s -b 0.0.0.0<\/code><\/pre>\n\n\n\nYou should get the Rails 5 welcome page...<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" loading=\"lazy\" width=\"555\" height=\"569\" src=\"https:\/\/erwin.co\/wp-content\/uploads\/2022\/06\/image-2.png\" alt=\"\" class=\"wp-image-162\" srcset=\"https:\/\/erwin.co\/wp-content\/uploads\/2022\/06\/image-2.png 555w, https:\/\/erwin.co\/wp-content\/uploads\/2022\/06\/image-2-293x300.png 293w\" sizes=\"(max-width: 555px) 100vw, 555px\" \/><\/figure>\n\n\n\nYour other also very easy option is to just switch to a <code>Ruby 3.1.2<\/code> based image... So in your Dockerfile just use:<\/p>\n\n\n\n<code>From: ruby:3.1.2 # instead of From: ruby:2.6<\/code><\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" loading=\"lazy\" width=\"703\" height=\"300\" src=\"https:\/\/erwin.co\/wp-content\/uploads\/2022\/06\/image-3.png\" alt=\"\" class=\"wp-image-163\" srcset=\"https:\/\/erwin.co\/wp-content\/uploads\/2022\/06\/image-3.png 703w, https:\/\/erwin.co\/wp-content\/uploads\/2022\/06\/image-3-300x128.png 300w\" sizes=\"(max-width: 703px) 100vw, 703px\" \/><\/figure>\n\n\n\nThe examples are so simple from a Ruby perspective that you should be fine either way. Always comforting when your screenshots exactly match the authors though, so I would stick with Rails 5.2.2 and Ruby 2.6 and work though this short book.<\/p>\n\n\n\nHighly recommend this one though. Changed the way I think about Docker, especially all the <code>docker-compose<\/code> stuff.<\/p>\n\n\n\nOnce you get to Chapter 7, Playing Nice with JavaScript<\/em>, the Ruby 2.6<\/em> instructions really start to break down. Node 8 and Node 10 are deprecated, so you'll need to move to Node 12, and the default packages for that aren't compatible with the Debian base image that Ruby 2.6 is built on.<\/p>\n\n\n\nWith Rails 7, we've kind of moved on from WebPacker anyway, but if you really want to do that part, I got it to build fine by using this as my Dockerfile.Basically, set ruby to 3.1.2, use <code>setup_12.x<\/code> for Node JS AND<\/span><\/em><\/strong> make sure to generate your rails app with Rails 7.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u00e2\u009d\u00af cat Dockerfile \nFROM ruby:3.1.2\n\nRUN apt-get update -yqq &&\\\n apt-get install -yqq --no-install-recommends \\\n apt-transport-https\n\nRUN curl -sL https:\/\/deb.nodesource.com\/setup_12.x | bash -\n\nRUN curl -sS https:\/\/dl.yarnpkg.com\/debian\/pubkey.gpg | apt-key add -\nRUN echo \"deb https:\/\/dl.yarnpkg.com\/debian\/ stable main\" | \\\n tee \/etc\/apt\/sources.list.d\/yarn.list\n\nRUN apt-get update -yqq &&\\\n apt-get install -yqq --no-install-recommends \\\n apt-utils \\\n nodejs \\\n yarn \\\n vim\n\nCOPY . \/usr\/src\/app\n\nWORKDIR \/usr\/src\/app\nRUN bundle install<\/code><\/pre>\n\n\n\nWebpacker comes up again in <code>Advanced Gem Management<\/code> and finally in Chapter 13, <code>A Production-Like Playground<\/code>.<\/p>\n\n\n\nThe Rspec\/testing chapter doesn't use Node or webpacker, so you can tear the yarn and nodejs update stuff out of your Dockerfile and get rid of Webpacker in your <code>Gemfile<\/code>.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>FROM ruby:2.6\n\nLABEL maintainer=\"erwin@fastmail.org\"\nLABEL foo=\"bar\"\n\nRUN apt-get update -yqq &&\\\n apt-get install -yqq --no-install-recommends \\\n apt-utils \\\n nodejs \\\n vim\n\nCOPY Gemfile* \/usr\/src\/app\/\nWORKDIR \/usr\/src\/app\nRUN bundle install\n\nCOPY . \/usr\/src\/app\/\n\nCMD [\"bin\/rails\", \"server\", \"-b\", \"0.0.0.0\"]<\/code><\/pre>\n\n\n\nThe automated testing with Capybara\/Selenium didn't work for me, but I've done some browser automation with Goland and Chrome so I didn't want to spend a lot of time debugging it. If you want to do the RSpec\/Capybara test examples in 2022, probably best to reference this post instead:<\/p>\n\n\n\n<a href=\"https:\/\/dev.to\/amree\/ruby-on-rails-and-docker-for-testing-4n8a\">https:\/\/dev.to\/amree\/ruby-on-rails-and-docker-for-testing-4n8a<\/a><\/p>\n\n\n\nThe authors tutorial approach of working though each step a piece at a time was extremely helpful for me, even being fairly familiar with Docker, but passively as a developer\/user without having been excited enough to deep dive into Docker itself.<\/p>\n","protected":false},"excerpt":{"rendered":"The pragprog team has a great book called “Docker for Rails Developers” however it’s about 3 year old now… So just some minor notes here on how to make everything work right in Ruby 3 \/ Rails 7 world. Docker is primary designed for deploying finished images of your software to production. Docker can work […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[14,13],"tags":[],"_links":{"self":[{"href":"https:\/\/erwin.co\/wp-json\/wp\/v2\/posts\/161"}],"collection":[{"href":"https:\/\/erwin.co\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/erwin.co\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/erwin.co\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/erwin.co\/wp-json\/wp\/v2\/comments?post=161"}],"version-history":[{"count":4,"href":"https:\/\/erwin.co\/wp-json\/wp\/v2\/posts\/161\/revisions"}],"predecessor-version":[{"id":170,"href":"https:\/\/erwin.co\/wp-json\/wp\/v2\/posts\/161\/revisions\/170"}],"wp:attachment":[{"href":"https:\/\/erwin.co\/wp-json\/wp\/v2\/media?parent=161"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/erwin.co\/wp-json\/wp\/v2\/categories?post=161"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/erwin.co\/wp-json\/wp\/v2\/tags?post=161"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}