package common import ( "fmt" "github.com/mitchellh/multistep" "github.com/mitchellh/packer/packer" "log" "math/rand" "net" "net/http" ) // This step creates and runs the HTTP server that is serving files from the // directory specified by the 'http_directory` configuration parameter in the // template. // // Uses: // ui packer.Ui // // Produces: // http_port int - The port the HTTP server started on. type StepHTTPServer struct { HTTPDir string HTTPPortMin uint HTTPPortMax uint l net.Listener } func (s *StepHTTPServer) Run(state multistep.StateBag) multistep.StepAction { ui := state.Get("ui").(packer.Ui) var httpPort uint = 0 if s.HTTPDir == "" { state.Put("http_port", httpPort) return multistep.ActionContinue } // Find an available TCP port for our HTTP server var httpAddr string portRange := int(s.HTTPPortMax - s.HTTPPortMin) for { var err error var offset uint = 0 if portRange > 0 { // Intn will panic if portRange == 0, so we do a check. offset = uint(rand.Intn(portRange)) } httpPort = offset + s.HTTPPortMin httpAddr = fmt.Sprintf(":%d", httpPort) log.Printf("Trying port: %d", httpPort) s.l, err = net.Listen("tcp", httpAddr) if err == nil { break } } ui.Say(fmt.Sprintf("Starting HTTP server on port %d", httpPort)) // Start the HTTP server and run it in the background fileServer := http.FileServer(http.Dir(s.HTTPDir)) server := &http.Server{Addr: httpAddr, Handler: fileServer} go server.Serve(s.l) // Save the address into the state so it can be accessed in the future state.Put("http_port", httpPort) return multistep.ActionContinue } func (s *StepHTTPServer) Cleanup(multistep.StateBag) { if s.l != nil { // Close the listener so that the HTTP server stops s.l.Close() } }