gitlab-org--gitlab-foss/config/initializers/6_validations.rb

def storage_name_valid?(name)
  !!(name =~ /\A[a-zA-Z0-9\-_]+\z/)
end

def find_parent_path(name, path)
  parent = Pathname.new(path).realpath.parent
  Gitlab.config.repositories.storages.detect do |n, p|
    name != n && Pathname.new(p).realpath == parent
  end
end

def storage_validation_error(message)
  raise "#{message}. Please fix this in your gitlab.yml before starting GitLab."
end

def validate_storages
  storage_validation_error('No repository storage path defined') if Gitlab.config.repositories.storages.empty?

  Gitlab.config.repositories.storages.each do |name, path|
    storage_validation_error("\"#{name}\" is not a valid storage name") unless storage_name_valid?(name)

    parent_name, _parent_path = find_parent_path(name, path)
    if parent_name
      storage_validation_error("#{name} is a nested path of #{parent_name}. Nested paths are not supported for repository storages")
    end
  end
end

validate_storages unless Rails.env.test? || ENV['SKIP_STORAGE_VALIDATION'] == 'true'