Use rbenv instead of RVM

I can't reliably install RVM on Ubuntu in an installer script such as
this, even with the supplied RVM Ubuntu package. Use rbenv instead like
the Windows and macOS installer guides also use.

Author: tombruijn

rails-install-ubuntu.sh

@@ -22,16 +22,35 @@ sudo snap install node --classic --channel=18
 echo "Installs ImageMagick for image processing"
 sudo apt-get install imagemagick --fix-missing -y
 
-echo "Installs RVM (Ruby Version Manager) for handling Ruby installation"
-# Retrieve the GPG key.
-curl -sSL https://rvm.io/pkuczynski.asc | gpg --import -
-curl -sSL https://get.rvm.io | bash -s stable
-source ~/.rvm/scripts/rvm
+echo "Install rbenv (Ruby version manager) for handling the Ruby installation"
+echo "gem: --no-ri --no-rdoc" > ~/.gemrc
+
+RBENV_INSTALL_PATH="$HOME/.rbenv"
+if [ -d "$RBENV_INSTALL_PATH" ]; then
+  echo "rbenv already installed"
+else
+  curl -fsSL https://github.com/rbenv/rbenv-installer/raw/HEAD/bin/rbenv-installer | bash
+
+  echo "Configuring rbenv for your Shell"
+  if [[ "$SHELL" == *"bash" ]]; then
+    echo 'eval "$($HOME/.rbenv/bin/rbenv init - bash)"' >> ~/.bashrc
+  elif [[ "$SHELL" == *"zsh" ]]; then
+    echo 'eval "$($HOME/.rbenv/bin/rbenv init - zsh)"' >> ~/.zshrc
+  else
+    echo "Unknown Shell. Please configure rbenv manually."
+    echo "Please visit: https://github.com/rbenv/rbenv"
+  fi
+fi
 
-echo "Installs Ruby"
-rvm install 3.1.2
-rvm use 3.1.2 --default
+echo "Load rbenv config in install script"
+eval "$($HOME/.rbenv/bin/rbenv init - bash)"
 
+echo "Install Ruby"
+RUBY_VERSION=3.1.3
+rbenv install "$RUBY_VERSION"
+rbenv global "$RUBY_VERSION"
+
+echo "Install Rails"
 echo "gem: --no-ri --no-rdoc" > ~/.gemrc
 gem install bundler rails
 
@@ -41,9 +60,7 @@ echo -e "Now we are going to print some information to check that everything is
 
 echo -n "Should be sqlite 3.22.0 or higher: sqlite "
 sqlite3 --version
-echo -n "Should be rvm 1.29.8 or higher:         "
-rvm --version | sed '/^.*$/N;s/\n//g' | cut -c 1-11
-echo -n "Should be ruby 3.0 or higher:                "
+echo -n "Should be Ruby 3.1.3 or higher:                "
 ruby -v | cut -d " " -f 2
 echo -n "Should be Rails 7.0 or higher:         "
 rails -v
@@ -55,12 +72,6 @@ and we will help you do the installation the manual way at the event.
 
 Congrats!
 
-Make sure that all works well by running the application generator command:
-    $ rails new railsgirls
-
-If you encounter the message:
-    The program 'rails' is currently not installed.
-
-It is just a hiccup with the shell, solutions:
-    $ source ~/.rvm/scripts/rvm
-    Allow login shell, example http://rvm.io/integration/gnome-terminal/"
+Open a new Terminal tab/window and make sure that all works well
+by running the application generator command:
+    $ rails new railsgirls"