Windows: factor out bridge server+config

Signed-off-by: John Howard <jhoward@microsoft.com>

api/server/server_linux.go

@@ -6,10 +6,12 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"strconv"
 
 	"github.com/docker/docker/daemon"
 	"github.com/docker/docker/pkg/sockets"
 	"github.com/docker/docker/pkg/systemd"
+	"github.com/docker/libnetwork/portallocator"
 )
 
 // newServer sets up the required serverCloser and does protocol specific checking.
@@ -76,3 +78,30 @@ func (s *Server) AcceptConnections(d *daemon.Daemon) {
 		close(s.start)
 	}
 }
+
+func allocateDaemonPort(addr string) error {
+	host, port, err := net.SplitHostPort(addr)
+	if err != nil {
+		return err
+	}
+
+	intPort, err := strconv.Atoi(port)
+	if err != nil {
+		return err
+	}
+
+	var hostIPs []net.IP
+	if parsedIP := net.ParseIP(host); parsedIP != nil {
+		hostIPs = append(hostIPs, parsedIP)
+	} else if hostIPs, err = net.LookupIP(host); err != nil {
+		return fmt.Errorf("failed to lookup %s address in host specification", host)
+	}
+
+	pa := portallocator.Get()
+	for _, hostIP := range hostIPs {
+		if _, err := pa.RequestPort(hostIP, "tcp", intPort); err != nil {
+			return fmt.Errorf("failed to allocate daemon listening port %d (err: %v)", intPort, err)
+		}
+	}
+	return nil
+}