feat(diagnosis): add host interface detection for flannel & calico pl…

…ugin

Signed-off-by: xiayu.lyt <xiayu.lyt@alibaba-inc.com>

pkg/skoop/netstack/link.go

@@ -2,8 +2,13 @@ package netstack
 
 import (
 	"net"
+	"regexp"
+
+	"github.com/samber/lo"
 )
 
+var defaultInterfaceNames = []string{"eth0", "eno0"}
+
 type Addr struct {
 	*net.IPNet
 }
@@ -55,3 +60,26 @@ func GetDefaultIPv4(iface *Interface) (net.IP, net.IPMask) {
 	}
 	return defaultIP, net.CIDRMask(32, 32)
 }
+
+func LookupDefaultIfaceName(ifaces []Interface) string {
+	// find interfaces in default names
+	for _, n := range defaultInterfaceNames {
+		if lo.ContainsBy(ifaces, func(i Interface) bool {
+			return i.Name == n
+		}) {
+			return n
+		}
+	}
+
+	// find first interfaces matched enp[0-9]+s[0-9]+.*
+	regex := regexp.MustCompile("^enp[0-9]+s[0-9]+.*$")
+	filtered := lo.Filter(ifaces, func(i Interface, _ int) bool {
+		return regex.MatchString(i.Name)
+	})
+
+	if len(filtered) != 0 {
+		return filtered[0].Name
+	}
+
+	return ""
+}

pkg/skoop/netstack/link_test.go

@@ -0,0 +1,40 @@
+package netstack
+
+import "testing"
+
+func TestLookupDefaultIfaceName(t *testing.T) {
+	testcases := []struct {
+		ifaces   []string
+		expected string
+	}{
+		{
+			ifaces:   []string{"eth0", "eno0", "ipvs0", "cali123456"},
+			expected: "eth0",
+		},
+		{
+			ifaces:   []string{"enp1s2", "eno0", "ipvs0", "cali123456"},
+			expected: "eno0",
+		},
+		{
+			ifaces:   []string{"enp1s1", "ipvs0", "cali123456"},
+			expected: "enp1s1",
+		},
+		{
+			ifaces:   []string{"wg0", "ipvs0", "cni0"},
+			expected: "",
+		},
+	}
+
+	for _, c := range testcases {
+		var ifs []Interface
+		for _, i := range c.ifaces {
+			ifs = append(ifs, Interface{Name: i})
+		}
+
+		result := LookupDefaultIfaceName(ifs)
+		if result != c.expected {
+			t.Errorf("excepted testcase %v to be %s, but %s", c.ifaces, c.expected, result)
+			t.FailNow()
+		}
+	}
+}

pkg/skoop/plugin/calico.go

@@ -8,6 +8,8 @@ import (
 	"net"
 	"strings"
 
+	"k8s.io/klog/v2"
+
 	"github.com/spf13/pflag"
 
 	"github.com/alibaba/kubeskoop/pkg/skoop/assertions"
@@ -33,7 +35,7 @@ type CalicoConfig struct {
 }
 
 func (c *CalicoConfig) BindFlags(fs *pflag.FlagSet) {
-	fs.StringVarP(&c.Interface, "calico-host-interface", "", "eth0",
+	fs.StringVarP(&c.Interface, "calico-host-interface", "", "",
 		"Host interface for calico plugin.")
 	fs.IntVarP(&c.PodMTU, "calico-pod-mtu", "", 1500,
 		"Pod MTU for calico plugin. Pod interface MTU in BGP mode.")
@@ -331,6 +333,13 @@ func newCalicoHost(ipCache *k8s.IPCache, nodeInfo *k8s.NodeInfo, infraShim netwo
 		k8s:              k8sAssertion,
 		infraShim:        infraShim,
 	}
+	if host.iface == "" {
+		host.iface = netstack.LookupDefaultIfaceName(nodeInfo.NetNSInfo.Interfaces)
+		if host.iface == "" {
+			return nil, fmt.Errorf("cannot lookup default host interface, please manually specify it via --calico-host-interface")
+		}
+		klog.V(5).Infof("detected host interface %s on node %s", host.iface, host.nodeInfo.NodeName)
+	}
 
 	err := host.initRoute()
 	if err != nil {

pkg/skoop/plugin/flannel.go

@@ -47,7 +47,7 @@ func (f *FlannelConfig) BindFlags(fs *pflag.FlagSet) {
 		"Pod MTU for flannel plugin. If not set, it will auto detect from flannel cni mode (1450 for vxlan, 1500 for others).")
 	fs.BoolVarP(&f.IPMasq, "flannel-ip-masq", "", true,
 		"Should do IP masquerade for flannel plugin.")
-	fs.StringVarP(&f.Interface, "flannel-host-interface", "", "eth0",
+	fs.StringVarP(&f.Interface, "flannel-host-interface", "", "",
 		"Host interface for flannel plugin.")
 }
 
@@ -474,6 +474,14 @@ func newFlannelHost(ipCache *k8s.IPCache, nodeInfo *k8s.NodeInfo, infraShim netw
 		serviceProcessor: serviceProcessor,
 	}
 
+	if host.iface == "" {
+		host.iface = netstack.LookupDefaultIfaceName(nodeInfo.NetNSInfo.Interfaces)
+		if host.iface == "" {
+			return nil, fmt.Errorf("cannot lookup default host interface, please manually specify it via --flannel-host-interface")
+		}
+		klog.V(5).Infof("detected host interface %s on node %s", host.iface, host.nodeInfo.NodeName)
+	}
+
 	err = host.initRoute()
 	if err != nil {
 		return nil, err