"gocage migrate jail -d destination_dataset" working for cold migrations

cmd/utils.go

@@ -1,17 +1,18 @@
 package cmd
 
 import (
+	"io"
+	"os"
+	"fmt"
+	"log"
+	"sort"
 	"bufio"
 	"errors"
-	"fmt"
-	"io/ioutil"
-	"log"
-	"os"
 	"os/exec"
 	"reflect"
-	"sort"
 	"strconv"
 	"strings"
+	"io/ioutil"
 )
 
 const (
@@ -214,6 +215,59 @@ func executeCommandInJail(jail *Jail, cmdline string) (string, error) {
 	return string(out), err
 }
 
+func zfsSnapshot(dataset string, snapname string) error {
+	cmd := fmt.Sprintf("zfs snapshot %s@%s", dataset, snapname)
+	out, err := executeCommand(cmd)
+	if err != nil {
+		return errors.New(fmt.Sprintf("%v; command returned \"%s\"", err, out))
+	}
+	return nil
+}
+
+func zfsCopy(src string, dest string) error {
+	// First, declare sending process & pipe
+	cmd_send := exec.Command("zfs", "send", src)
+	stdout_send, err := cmd_send.StdoutPipe()
+	if err != nil {
+		//fmt.Printf("Error executing command \"zfs send %s\": %v\n", fmt.Sprintf("%s@gocage_mig_init", dsconf), err)
+		return errors.New(fmt.Sprintf("Error: %v\n", err))
+	}
+	
+	// then declare receiving process & pipe
+	cmd_recv := exec.Command("zfs", "receive", dest)
+	stdin_recv, err := cmd_recv.StdinPipe()
+	if err != nil {
+		//fmt.Printf("Error executing command \"zfs receive %s\": %v\n", dest, err)
+		return errors.New(fmt.Sprintf("Error: %v\n", err))
+	}
+	
+	// Copy data in a go routine
+	go io.Copy(stdin_recv, stdout_send)
+	
+	// then start processes and wait for finish
+	if err := cmd_recv.Start(); err != nil {
+		//fmt.Printf("Error: %v\n", err)
+		return errors.New(fmt.Sprintf("Error starting receive process: %v\n", err))
+	}
+	//fmt.Printf("DEBUG: Start \"zfs send %s\"\n", dsconf)
+	if err := cmd_send.Start(); err != nil {
+		//fmt.Printf("Error: %v\n", err)
+		return errors.New(fmt.Sprintf("Error starting send process: %v\n", err))
+	}
+	
+	//fmt.Printf("DEBUG: Wait for zfs send to finish\n")
+	if err := cmd_send.Wait(); err != nil {
+		//fmt.Printf("Error: zfs send halted with %v\n", err)
+		return errors.New(fmt.Sprintf("send halted with: %v\n", err))
+	}
+	//fmt.Printf("DEBUG: Wait for zfs recv to finish\n")
+	if err := cmd_recv.Wait(); err != nil {
+		//fmt.Printf("Error: zfs recv halted with %v\n", err)
+		return errors.New(fmt.Sprintf("receive halted with: %v\n", err))
+	}
+
+	return nil
+}
 /*****************************************************************************
  *
  * rc.conf management