You need to define route like this:
RedmineApp::Application.routes.draw do
match 'issue/:issue_id/something/:action/:id', to: 'something#new_some', as: 'fancy_route'
end
After that register this route in your plugin:
project_module :my_plugin do
permission :my_plugin, { :my_plugin => [:fancy_route] },:public => true
end
Live example from iCalendar plugin:
project_module :redmine_icalendar do
permission :redmine_icalendar, {:redmine_icalendar => [:index, :show, :list]}, :public => true
permission :redmine_icalendar, {:redmine_icalendar => [:edit, :new, :destroy]}, :require => :member
end