Merge pull request #6 from ahmetozer/feat/issues3

feat: wait until interface is ready.

pkg/cmd/run.go

@@ -49,7 +49,7 @@ func run(args []string) error {
 	PodIface := config.NetIface{Type: "veth"}
 	f.StringVar(&PodIface.IP, "pod-ips", "", "container interface ips")
 
-	f.StringVar(&c.Resolv, "resolv", "cp-n", "cp (copy), cp-n (copy if not exist), image (use image), 1.1.1.1;2606:4700:4700::1111 (provide nameservers)")
+	f.StringVar(&c.Resolv, "resolv", "cp", "cp (copy), cp-n (copy if not exist), image (use image), 1.1.1.1;2606:4700:4700::1111 (provide nameservers)")
 	f.StringVar(&c.Hosts, "hosts", "cp", "cp (copy), cp-n (copy if not exist), image(use image)")
 
 	f.StringVar(&c.NS.Net, "ns-net", "", "net namespace or host")
@@ -68,11 +68,6 @@ func run(args []string) error {
 	if c.RootfsDir == "" {
 		c.RootfsDir = defaultRootfs(&c)
 	}
-	c.Ifaces = []config.NetIface{HostIface}
-	PodIface.Main = append(PodIface.Main, HostIface)
-	if PodIface.IP == "" {
-		PodIface.IP = net.FindFreePodIPs(HostIface.IP)
-	}
 
 	if help {
 		f.Usage()
@@ -91,6 +86,12 @@ func run(args []string) error {
 		return fmt.Errorf("container %s is already running", c.Name)
 	}
 
+	c.Ifaces = []config.NetIface{HostIface}
+	PodIface.Main = append(PodIface.Main, HostIface)
+	if PodIface.IP == "" {
+		PodIface.IP = net.FindFreePodIPs(HostIface.IP)
+	}
+
 	if c.NS.Net != "host" {
 
 		if HostIface.Type == "bridge" {

pkg/container/exec.go

@@ -26,10 +26,6 @@ func Exec() {
 	childSysMounts(&c)
 	childSysNodes(&c)
 
-	if err := net.SetInterfaceUp("lo"); err != nil {
-		log.Fatalf("unable to set lo up %s", err)
-	}
-
 	_, args := childArgs(os.Args)
 	if err := unix.Exec(c.Exec, append([]string{c.Exec}, args...), os.Environ()); err != nil {
 		log.Fatalf("unable to exec %s: %s", c.Exec, err)
@@ -57,9 +53,15 @@ func loadConfig() (config.Config, error) {
 
 func configureIfaces(c *config.Config) {
 	var err error
-	ethNo := 0
+	var ethNo uint8 = 0
 	for i := range c.Ifaces {
 		if c.Ifaces[i].ALocFor == config.ALocForPod {
+
+			err = net.WaitInterface(c.Ifaces[i].Name)
+			if err != nil {
+				log.Fatalf("%s", err)
+			}
+
 			err = net.SetName(c, c.Ifaces[i].Name, fmt.Sprintf("eth%d", ethNo))
 			if err != nil {
 				log.Fatalf("unable to set name %s", err)
@@ -74,11 +76,16 @@ func configureIfaces(c *config.Config) {
 			if err != nil {
 				log.Fatalf("unable to set eth%d up %s", ethNo, err)
 			}
+
 			if ethNo == 0 {
 				net.AddDefaultRoutes(c.Ifaces[i])
 			}
 
 			ethNo++
 		}
 	}
+
+	if err := net.SetInterfaceUp("lo"); err != nil {
+		log.Fatalf("unable to set lo up %s", err)
+	}
 }

pkg/container/start.go

@@ -78,6 +78,7 @@ func Start(c *config.Config, args []string) (int, error) {
 	}
 
 	c.SaveConftoDisk()
+
 	err := cmd.Start()
 	if err != nil {
 		return 0, fmt.Errorf("starting container: %v", err)
@@ -87,7 +88,9 @@ func Start(c *config.Config, args []string) (int, error) {
 	loadNamespaceIDs(c)
 
 	c.Status = ContainerStatusRunning
+
 	c.SaveConftoDisk()
+
 	for _, iface := range c.Ifaces {
 		if iface.ALocFor == config.ALocForPod {
 			err = net.SetNs(iface, c.ContPid)

pkg/net/clear.go

@@ -14,7 +14,7 @@ func Clear(c *config.Config) {
 			link, err := netlink.LinkByName(iface.Name)
 			if err == nil && link != nil {
 				if err := netlink.LinkDel(link); err != nil {
-					slog.Info("linkdel: %v", err)
+					slog.Info("linkdel:", slog.String("err", err.Error()))
 				}
 			}
 		}

pkg/net/create.go

@@ -98,6 +98,7 @@ func CreateIface(c *config.Config, iface *config.NetIface) error {
 		ifname := NewIfName(c)
 
 		ifaceLink = &netlink.Veth{LinkAttrs: netlink.LinkAttrs{Name: ifname.Host, MasterIndex: masterlink.Attrs().Index}, PeerName: ifname.Cont}
+		netlink.LinkDel(ifaceLink)
 		if err = netlink.LinkAdd(ifaceLink); err != nil {
 			return fmt.Errorf("error creating container host interface: %v", err)
 		}

pkg/net/iface.go

@@ -1,6 +1,9 @@
 package net
 
 import (
+	"fmt"
+	"time"
+
 	"github.com/ahmetozer/sandal/pkg/config"
 	"github.com/vishvananda/netlink"
 	"golang.org/x/sys/unix"
@@ -54,3 +57,33 @@ func SetInterfaceUp(name string) error {
 	err = netlink.LinkSetUp(link)
 	return err
 }
+
+func WaitInterface(name string) error {
+
+	interfaceReady := make(chan bool)
+
+	go func(killed chan<- bool) {
+		for {
+			link, err := netlink.LinkByName(name)
+			if err != nil {
+				fmt.Printf("%s", err)
+			}
+			if err == nil && link != nil {
+				interfaceReady <- true
+				break
+			}
+			time.Sleep(time.Second)
+		}
+	}(interfaceReady)
+
+	select {
+	case ret := <-interfaceReady:
+		if !ret {
+			return fmt.Errorf("unable to get interface")
+		}
+		return nil
+	case <-time.After(5 * time.Second):
+		return fmt.Errorf("unable to get interface %s in 5 second", name)
+	}
+
+}