l2: exclude common virtual interfaces for announce services

In arp mode, Some common virtual interfaces should not be used to announce services, such as kube-ipvs0, docker0, etc. This PR will dispatch these common virtual interfaces.

Signed-off-by: cyclinder <qifeng.guo@daocloud.io>

internal/layer2/announcer.go

@@ -5,7 +5,9 @@ package layer2
 import (
 	"net"
 	"os"
+	"regexp"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -26,7 +28,8 @@ type Announce struct {
 
 	// This channel can block - do not write to it while holding the mutex
 	// to avoid deadlocking.
-	spamCh chan IPAdvertisement
+	spamCh        chan IPAdvertisement
+	excludeRegexp *regexp.Regexp
 }
 
 // New returns an initialized Announce.
@@ -40,6 +43,13 @@ func New(l log.Logger) (*Announce, error) {
 		ipRefcnt:       map[string]int{},
 		spamCh:         make(chan IPAdvertisement, 1024),
 	}
+	excludeRegexp, err := regexp.Compile("(" + strings.Join(DefaultInterfacesToExclude, ")|(") + ")")
+	if err != nil {
+		level.Error(l).Log("error", err, "msg", "couldn't get excludeRegexp")
+		return nil, err
+	}
+	ret.excludeRegexp = excludeRegexp
+
 	go ret.interfaceScan()
 	go ret.spamLoop()
 
@@ -67,6 +77,12 @@ func (a *Announce) updateInterfaces() {
 	curIfs := make([]string, 0, len(ifs))
 	for _, intf := range ifs {
 		ifi := intf
+
+		if (a.excludeRegexp != nil) && a.excludeRegexp.MatchString(ifi.Name) {
+			level.Info(a.logger).Log("event", "exclude interface", ifi.Name)
+			continue
+		}
+
 		curIfs = append(curIfs, ifi.Name)
 		l := log.With(a.logger, "interface", ifi.Name)
 		addrs, err := ifi.Addrs()
@@ -337,3 +353,10 @@ const (
 	dropReasonAnnounceIP
 	dropReasonNotMatchInterface
 )
+
+// DefaultInterfacesToExclude the interfaces in the list not be used to service announce.
+var DefaultInterfacesToExclude = []string{
+	"docker.*", "cbr.*", "dummy.*",
+	"virbr.*", "lxcbr.*", "veth.*", "lo",
+	"^cali.*", "^tunl.*", "flannel.*", "kube-ipvs.*", "cni.*", "^nodelocaldns.*",
+}