⬆️ Ruby 4.0.0

Author: ledermann

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  TAG_NAME: 3.4.8-alpine
+  TAG_NAME: 4.0.0-alpine
 
 jobs:
   build:

.ruby-version

@@ -1 +1 @@
-3.4.8
+4.0.0

README.md

@@ -44,7 +44,7 @@ It uses [multi-stage building](https://docs.docker.com/develop/develop-images/mu
 
 The `builder` stage installs Ruby gems and Node modules. It also includes Git, Node.js and some build tools - all we need to compile assets.
 
-- Based on [ruby:3.4.8-alpine](https://github.com/docker-library/ruby/blob/master/3.4/alpine3.23/Dockerfile)
+- Based on [ruby:4.0.0-alpine](https://github.com/docker-library/ruby/blob/master/4.0/alpine3.23/Dockerfile)
 - Adds packages needed for installing gems and compiling assets: Git, Node.js, PostgreSQL client and build tools
 - Adds some default Ruby gems (Rails 8.0 etc., see [Gemfile](./builder/Gemfile))
 - Via ONBUILD triggers it installs missing gems and Node modules, then compiles the assets
@@ -59,7 +59,7 @@ See [builder/Dockerfile](./builder/Dockerfile)
 
 The `final` stage builds the production image, which includes just the bare minimum.
 
-- Based on [ruby:3.4.8-alpine](https://github.com/docker-library/ruby/blob/master/3.4/alpine3.23/Dockerfile)
+- Based on [ruby:4.0.0-alpine](https://github.com/docker-library/ruby/blob/master/4.0/alpine3.23/Dockerfile)
 - Adds packages needed for production: postgresql-client, tzdata, file
 - Via ONBUILD triggers it mainly copies the app and gems from the `builder` stage
 
@@ -76,8 +76,8 @@ Using [Dependabot](https://dependabot.com/), every updated Ruby gem results in a
 Add this `Dockerfile` to your application:
 
 ```Dockerfile
-FROM ghcr.io/ledermann/rails-base-builder:3.4.8-alpine AS builder
-FROM ghcr.io/ledermann/rails-base-final:3.4.8-alpine
+FROM ghcr.io/ledermann/rails-base-builder:4.0.0-alpine AS builder
+FROM ghcr.io/ledermann/rails-base-final:4.0.0-alpine
 USER app
 # Optional: Enable YJIT
 # ENV RUBY_YJIT_ENABLE=1
@@ -167,6 +167,7 @@ When a new Ruby version comes out, a new tag is introduced and the images will b
 
 | Ruby version | Tag          | First published |
 | ------------ | ------------ | --------------- |
+| 4.0.0        | 4.0.0-alpine | 2025-12-28      |
 | 3.4.8        | 3.4.8-alpine | 2025-12-18      |
 | 3.4.7        | 3.4.7-alpine | 2025-10-09      |
 | 3.4.6        | 3.4.6-alpine | 2025-09-17      |

builder/Dockerfile

@@ -1,7 +1,7 @@
 # syntax=docker/dockerfile:1
 # check=error=true
 
-FROM ruby:3.4.8-alpine
+FROM ruby:4.0.0-alpine
 LABEL maintainer="georg@ledermann.dev"
 
 # Add basic packages

builder/Gemfile

@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
-ruby '3.4.8'
+ruby '4.0.0'
 
 # Full-stack web application framework. (https://rubyonrails.org)
 gem 'rails', '~> 8.1.0'

builder/Gemfile.lock

@@ -99,6 +99,7 @@ GEM
     dry-cli (1.3.0)
     erb (6.0.1)
     erubi (1.13.1)
+    ffi (1.17.2)
     ffi (1.17.2-aarch64-linux-musl)
     ffi (1.17.2-arm64-darwin)
     ffi (1.17.2-x86_64-linux-gnu)
@@ -182,6 +183,7 @@ GEM
     pagy (43.2.2)
       json
       yaml
+    pg (1.6.2)
     pg (1.6.2-aarch64-linux-musl)
     pg (1.6.2-arm64-darwin)
     pg (1.6.2-x86_64-linux)
@@ -342,7 +344,7 @@ GEM
 
 PLATFORMS
   aarch64-linux-musl
-  arm64-darwin-25
+  arm64-darwin
   x86_64-linux
   x86_64-linux-musl
 
@@ -377,7 +379,7 @@ DEPENDENCIES
   vite_rails
 
 RUBY VERSION
-  ruby 3.4.8
+  ruby 4.0.0
 
 BUNDLED WITH
-  4.0.2
+  4.0.3

final/Dockerfile

@@ -1,7 +1,7 @@
 # syntax=docker/dockerfile:1
 # check=error=true
 
-FROM ruby:3.4.8-alpine
+FROM ruby:4.0.0-alpine
 LABEL maintainer="georg@ledermann.dev"
 
 # Add basic packages