devcontainer with ruby 2.6

.devcontainer/Dockerfile

@@ -0,0 +1,7 @@
+# [Choice] Ruby version (use -bullseye variants on local arm64/Apple Silicon): 3, 3.3, 3.2, 3.1, 3-bookworm, 3.3-bookworm, 3.2-bookworm, 3.1-bookworm, 3-bullseye, 3.3-bullseye, 3.2-bullseye, 3.1-bullseye, 3-buster, 3.2-buster 3.1-buster
+ARG VARIANT=2.6
+FROM ruby:${VARIANT}
+
+RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
+    # Remove imagemagick due to https://security-tracker.debian.org/tracker/CVE-2019-10131
+    && apt-get purge -y imagemagick imagemagick-6-common 

.devcontainer/devcontainer.json

@@ -1,22 +1,23 @@
-// For format details, see https://aka.ms/devcontainer.json. For config options, see the
-// README at: https://github.com/devcontainers/templates/tree/main/src/ruby
 {
-	"name": "Ruby",
-	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
-	"image": "mcr.microsoft.com/devcontainers/ruby:1-3.3-bullseye"
-
-	// Features to add to the dev container. More info: https://containers.dev/features.
-	// "features": {},
-
-	// Use 'forwardPorts' to make a list of ports inside the container available locally.
-	// "forwardPorts": [],
-
-	// Use 'postCreateCommand' to run commands after the container is created.
-	// "postCreateCommand": "ruby --version",
-
-	// Configure tool-specific properties.
-	// "customizations": {},
-
-	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
-	// "remoteUser": "root"
+    "build": {
+        "dockerfile": "./Dockerfile",
+        "context": "."
+    },
+    "features": {
+        "ghcr.io/devcontainers/features/common-utils:2": {
+            "installZsh": "true",
+            "username": "vscode",
+            "userUid": "1000",
+            "userGid": "1000",
+            "upgradePackages": "true"
+        },
+        "ghcr.io/devcontainers/features/ruby:1": "none",
+        "ghcr.io/devcontainers/features/node:1": "none",
+        "ghcr.io/devcontainers/features/git:1": {
+            "version": "latest",
+            "ppa": "false"
+        }
+    },
+    // Set `remoteUser` to `root` to connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+    "remoteUser": "vscode"
 }

gemfiles/rails_6_0.gemfile

@@ -5,10 +5,11 @@ source "https://rubygems.org"
 gem "rails", "~> 6.0.0"
 
 group :development, :test do
-  gem "sqlite3", '~> 1.4', platform: [:ruby, :mswin, :mingw]
+  gem "sqlite3", '~> 1.4.0', platform: [:ruby, :mswin, :mingw]
   gem "activerecord-jdbcsqlite3-adapter", "~> 1.3.13", platform: :jruby
   gem "test-unit", "~> 3.0"
   gem "psych", "~> 3.0"
+  gem "ffi", "~> 1.15.0"
 end
 
 gemspec path: "../"

gemfiles/rails_6_1.gemfile

@@ -8,9 +8,10 @@ gem "net-imap", require: false
 gem "net-pop", require: false
 
 group :development, :test do
-  gem "sqlite3", '~> 1.4', platform: [:ruby, :mswin, :mingw]
+  gem "sqlite3", '~> 1.4.0', platform: [:ruby, :mswin, :mingw]
   gem "activerecord-jdbcsqlite3-adapter", "~> 1.3.13", platform: :jruby
   gem "test-unit", "~> 3.0"
+  gem "ffi", "~> 1.15.0"
 end
 
 gemspec path: "../"