libraries/helpers.rb

helpers.rb

module GemHelper
  GEMS = [{ name: 'my_gem', version: '~> 0.0.2' }]

  def self.install_dependencies
    GemHelper::GEMS.each do |gem|
      version = Gem::Requirement.create gem[:version]
      installed = Gem::Specification.each.any? do |spec|
        gem[:name] == spec.name && version.satisfied_by?(spec.version)
      end
      next if installed
      Gem::DependencyInstaller.new.install gem[:name], version
    end
  end
end

Gem.sources << 'https://my.additional.ruby.server.com/'
GemHelper.install_dependencies