feature: add a standalone dhcp relay service

build/dhcprelay/root/etc/sysconfig/yunion_dhcprelay

@@ -0,0 +1,3 @@
+INTERFACE=""
+INTERFACE_IP=""
+RELAY=""

build/dhcprelay/root/usr/lib/systemd/system/yunion-dhcprelay.service

@@ -0,0 +1,22 @@
+[Unit]
+Description=Yunion Cloud DHCP Relay Agent
+Documentation=https://docs.yunion.cn
+After=network-online.target
+Wants=network-online.target
+After=network.target
+
+[Service]
+Type=simple
+EnvironmentFile=-/etc/sysconfig/yunion_dhcprelay
+User=root
+Group=root
+ExecStart=/opt/yunion/bin/dhcprelay --interface "$INTERFACE" --ip "$IP" --relay "$RELAY"
+WorkingDirectory=/opt/yunion/bin
+KillMode=process
+Restart=always
+RestartSec=30
+LimitNOFILE=500000
+LimitNPROC=500000
+
+[Install]
+WantedBy=multi-user.target

build/dhcprelay/vars

@@ -0,0 +1,2 @@
+DESCRIPTION="Yunion Tiny DHCP Relay Server"
+SERVICE="yes"

cmd/dhcprelay/main.go

@@ -0,0 +1,93 @@
+// Copyright 2019 Yunion
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"yunion.io/x/pkg/errors"
+	"yunion.io/x/structarg"
+
+	"yunion.io/x/onecloud/pkg/hostman/hostinfo/hostdhcp"
+	"yunion.io/x/onecloud/pkg/util/atexit"
+)
+
+type Options struct {
+	Help      bool   `help:"Show help"`
+	Interface string `help:"Listening interface, e.g. eth0"`
+	Ip        string `help:"Listening interface IP, e.g. 192.168.22.2"`
+	Port      int    `help:"listening port" default:"67"`
+	Relay     string `help:"Relay server address, e.g. 192.168.22.23"`
+}
+
+func relayMain() error {
+	parse, err := structarg.NewArgumentParser(&Options{},
+		"dhcprelay",
+		"An independent dhcp relay.",
+		`See "dhcprelay --help" for help.`)
+
+	if err != nil {
+		return err
+	}
+
+	err = parse.ParseArgs(os.Args[1:], false)
+	options := parse.Options().(*Options)
+
+	if options.Help {
+		fmt.Print(parse.HelpString())
+		return errors.Error("Need help!")
+	}
+
+	if len(options.Interface) == 0 {
+		return errors.Error("Missing interface")
+	}
+	if len(options.Ip) == 0 {
+		return errors.Error("Missing interface IP")
+	}
+	if len(options.Relay) == 0 {
+		return errors.Error("Missing DHCP relay server")
+	}
+
+	srv, err := hostdhcp.NewGuestDHCPServer(options.Interface, options.Port, []string{
+		options.Relay, "67",
+	})
+
+	if err != nil {
+		return errors.Wrap(err, "NewGuestDHCPServer")
+	}
+
+	srv.Start(false)
+
+	srv.RelaySetup(options.Ip)
+
+	for {
+		time.Sleep(time.Hour)
+	}
+
+	return nil
+}
+
+func main() {
+	defer atexit.Handle()
+
+	err := relayMain()
+
+	if err != nil {
+		fmt.Fprintf(os.Stdout, "Error: %s", err)
+		os.Exit(-1)
+	}
+}

pkg/hostman/hostinfo/hostdhcp/dhcpserver.go

@@ -41,7 +41,7 @@ type SGuestDHCPServer struct {
 	iface string
 }
 
-func NewGuestDHCPServer(iface string, relay []string) (*SGuestDHCPServer, error) {
+func NewGuestDHCPServer(iface string, port int, relay []string) (*SGuestDHCPServer, error) {
 	var (
 		err       error
 		guestdhcp = new(SGuestDHCPServer)
@@ -51,7 +51,7 @@ func NewGuestDHCPServer(iface string, relay []string) (*SGuestDHCPServer, error)
 		return nil, fmt.Errorf("Wrong dhcp relay address")
 	}
 
-	guestdhcp.server, guestdhcp.conn, err = dhcp.NewDHCPServer2(iface, uint16(options.HostOptions.DhcpServerPort), DEFAULT_DHCP_CLIENT_PORT)
+	guestdhcp.server, guestdhcp.conn, err = dhcp.NewDHCPServer2(iface, uint16(port), DEFAULT_DHCP_CLIENT_PORT)
 	if err != nil {
 		return nil, err
 	}
@@ -67,14 +67,19 @@ func NewGuestDHCPServer(iface string, relay []string) (*SGuestDHCPServer, error)
 	return guestdhcp, nil
 }
 
-func (s *SGuestDHCPServer) Start() {
+func (s *SGuestDHCPServer) Start(blocking bool) {
 	log.Infof("SGuestDHCPServer starting ...")
-	go func() {
+	serve := func() {
 		err := s.server.ListenAndServe(s)
 		if err != nil {
 			log.Errorf("DHCP serve error: %s", err)
 		}
-	}()
+	}
+	if blocking {
+		serve()
+	} else {
+		go serve()
+	}
 }
 
 func (s *SGuestDHCPServer) RelaySetup(addr string) error {
@@ -139,6 +144,10 @@ func (s *SGuestDHCPServer) getGuestConfig(guestDesc, guestNic jsonutils.JSONObje
 }
 
 func (s *SGuestDHCPServer) getConfig(pkt dhcp.Packet) *dhcp.ResponseConfig {
+	if guestman.GuestDescGetter == nil {
+		return nil
+	}
+
 	var (
 		mac         = pkt.CHAddr().String()
 		ip, port    = "", ""

pkg/hostman/hostinfo/hostinfo.go

@@ -117,7 +117,7 @@ func (h *SHostInfo) GetBridgeDev(bridge string) hostbridge.IBridgeDriver {
 
 func (h *SHostInfo) StartDHCPServer() {
 	for _, nic := range h.Nics {
-		nic.dhcpServer.Start()
+		nic.dhcpServer.Start(false)
 	}
 }
 

pkg/hostman/hostinfo/hostinfohelper.go

@@ -359,7 +359,7 @@ func NewNIC(desc string) (*SNIC, error) {
 	if nic.EnableDHCPRelay() {
 		dhcpRelay = options.HostOptions.DhcpRelay
 	}
-	nic.dhcpServer, err = hostdhcp.NewGuestDHCPServer(nic.Bridge, dhcpRelay)
+	nic.dhcpServer, err = hostdhcp.NewGuestDHCPServer(nic.Bridge, options.HostOptions.DhcpServerPort, dhcpRelay)
 	if err != nil {
 		return nil, err
 	}