Support binds in container exec command

This addresses issue #88.

internal/app/wwctl/container/exec/child/main.go

@@ -1,3 +1,4 @@
+//go:build linux
 // +build linux
 
 package child
@@ -6,6 +7,7 @@ import (
 	"fmt"
 	"os"
 	"path"
+	"strings"
 	"syscall"
 
 	"github.com/hpcng/warewulf/internal/pkg/container"
@@ -37,6 +39,27 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 		syscall.Mount("/etc/resolv.conf", path.Join(containerPath, "/etc/resolv.conf"), "", syscall.MS_BIND, "")
 	}
 
+	fmt.Printf("Evaluating bind points\n")
+	for _, b := range binds {
+		var source string
+		var dest string
+
+		bind := strings.Split(b, ":")
+		source = bind[0]
+
+		if len(bind) == 1 {
+			dest = source
+		} else {
+			dest = bind[1]
+		}
+
+		err := syscall.Mount(source, path.Join(containerPath, dest), "", syscall.MS_BIND, "")
+		if err != nil {
+			fmt.Printf("BIND ERROR: %s\n", err)
+			os.Exit(1)
+		}
+	}
+
 	syscall.Chroot(containerPath)
 	os.Chdir("/")
 

internal/app/wwctl/container/exec/child/root.go

@@ -10,10 +10,11 @@ var (
 		Args:               cobra.MinimumNArgs(1),
 		FParseErrWhitelist: cobra.FParseErrWhitelist{UnknownFlags: true},
 	}
+	binds []string
 )
 
 func init() {
-
+	baseCmd.PersistentFlags().StringArrayVarP(&binds, "bind", "b", []string{}, "bind points")
 }
 
 // GetRootCommand returns the root cobra.Command for the application.

internal/app/wwctl/container/exec/main.go

@@ -1,3 +1,4 @@
+//go:build linux
 // +build linux
 
 package exec
@@ -16,13 +17,21 @@ import (
 func CobraRunE(cmd *cobra.Command, args []string) error {
 
 	containerName := args[0]
+	var allargs []string
 
 	if container.ValidSource(containerName) == false {
 		wwlog.Printf(wwlog.ERROR, "Unknown Warewulf container: %s\n", containerName)
 		os.Exit(1)
 	}
 
-	c := exec.Command("/proc/self/exe", append([]string{"container", "exec", "__child"}, args...)...)
+	fmt.Println(args)
+
+	for _, b := range binds {
+		allargs = append(allargs, "--bind", b)
+	}
+	allargs = append(allargs, args...)
+
+	c := exec.Command("/proc/self/exe", append([]string{"container", "exec", "__child"}, allargs...)...)
 
 	//c := exec.Command("/bin/sh")
 	c.SysProcAttr = &syscall.SysProcAttr{

internal/app/wwctl/container/exec/root.go

@@ -16,10 +16,12 @@ var (
 		Args:               cobra.MinimumNArgs(1),
 		FParseErrWhitelist: cobra.FParseErrWhitelist{UnknownFlags: true},
 	}
+	binds []string
 )
 
 func init() {
 	baseCmd.AddCommand(child.GetCommand())
+	baseCmd.PersistentFlags().StringArrayVarP(&binds, "bind", "b", []string{}, "Bind a local path into the container (must exist)")
 }
 
 // GetRootCommand returns the root cobra.Command for the application.