lib/vagrant-notify/action/start_server.rb in vagrant-notify-0.2.2 vs lib/vagrant-notify/action/start_server.rb in vagrant-notify-0.3.0

@@ -1,23 +1,61 @@
+require "vagrant/util/is_port_open"
+
 require_relative '../server'
 
 module Vagrant
   module Notify
     module Action
       class StartServer
-        # TODO: This should come from vm configuration or be automatically
-        #       assigned
-        PORT = '9999'
+        include Util::IsPortOpen
 
         def initialize(app, env)
           @app = app
         end
 
         def call(env)
-          env[:notify_data][:pid]  = Server.run(env, PORT)
-          env[:notify_data][:port] = PORT
+          @env = env
 
+          port = next_available_port
+          env[:notify_data][:pid]  = Server.run(env, port)
+          env[:notify_data][:port] = port
+
           @app.call env
+        end
+
+        def next_available_port
+          # Determine a list of usable ports for us to use
+          usable_ports = Set.new(@env[:machine].config.vm.usable_port_range)
+
+          # Pass one, remove all defined host ports from usable ports
+          with_forwarded_ports do |options|
+            usable_ports.delete(options[:host])
+          end
+
+          # Pass two, remove ports used by other processes
+          with_forwarded_ports do |options|
+            host_port = options[:host]
+            usable_ports.delete(options[:host]) if is_port_open?("127.0.0.1", host_port)
+          end
+
+          # If we have no usable ports then we can't use the plugin
+          raise 'No usable ports available!' if usable_ports.empty?
+
+          # Set the port up to be the last one since vagrant's port collision handler
+          # will use the first as in:
+          #   https://github.com/mitchellh/vagrant/blob/master/lib/vagrant/action/builtin/handle_forwarded_port_collisions.rb#L84
+          usable_ports.to_a.sort.reverse.find do |port|
+            return port unless is_port_open?("127.0.0.1", port)
+          end
+        end
+
+        def with_forwarded_ports
+          @env[:machine].config.vm.networks.each do |type, options|
+            # Ignore anything but forwarded ports
+            next if type != :forwarded_port
+
+            yield options
+          end
         end
       end
     end
   end
 end