WIP migration on running jail with minimized downtime

cmd/migrate.go

@@ -3,10 +3,10 @@ package cmd
 import (
 	"os"
 	"fmt"
-	"strings"
 	"bufio"
-/*	"errors"
+	"errors"
-	"regexp"
+	"strings"
+/*	"regexp"
 	"time"
 */
 )
@@ -45,7 +45,7 @@ func MigrateJail(args []string) {
 		
 		if cj.Running == true {
 			fmt.Printf("WARNING: Jail %s is running\n", cj.Name)
-			fmt.Printf("Migration will stop it for data sync before starting on the new pool. You will be prompted for shutdown\n")
+			fmt.Printf("Migration will stop it for data sync before starting on the new pool. You will be prompted for shutdown.\n")
 			fmt.Printf("Continue? (y/n) ")
 			scanr := bufio.NewScanner(os.Stdin)
 			scanr.Scan()
@@ -59,11 +59,11 @@ func MigrateJail(args []string) {
 				zfs snapshot /iocage/jails/$jail@gocage_mig_first_snap
 				zfs snapshot /iocage/jails/$jail/root@gocage_mig_first_snap
 				zfs send jail@gocage_mig_first_snap | zfs receive destpool/jails/jail_name
-				zfs send jail/root@@gocage_mig_first_snap | zfs receive destpool/jails/jail_name/root
+				zfs send jail/root@gocage_mig_first_snap | zfs receive destpool/jails/jail_name/root
 				shutdown jail if needed
 				if jail was shutdown
 					zfs snapshot /iocage/jails/$jail@gocage_mig_last_snap to get last data
-					zfs send jail/root@gocage_mig_last_snap | zfs receive -F destpool/jails/jail_name
+					zfs send -i jail@gocage_mig_first_snap jail/root@gocage_mig_last_snap | zfs receive -F destpool/jails/jail_name
 					start jail on new dest
 					zfs destroy destpool/jails/jail_name@gocage_mig_first_snap
 					zfs destroy destpool/jails/jail_name/root@gocage_mig_first_snap
@@ -100,11 +100,64 @@ func MigrateJail(args []string) {
 			fmt.Printf("Error: %v\n", err)
 		}
 		fmt.Printf("Done\n")
+		
+		// Running jail needs a last snapshot for an incremental send/recv after shutting down.
+		if cj.Running == true {
+			fmt.Printf("Shutdown jail %s for last data sync, this could take some time.\n", cj.Name)
+			fmt.Printf("Continue? (y/n) ")
+			scanr := bufio.NewScanner(os.Stdin)
+			scanr.Scan()
+			if false == strings.EqualFold(scanr.Text(), "y") {
+				fmt.Printf("Migration aborted. Now cleaning destination pool.\n")
+				if err := CleanMigrateMess([]string{cj.Name}); err != nil {
+					fmt.Printf("Error: %v\n", err)
+				}
+				// TODO : Remove destination datasets, or handle the cas at the beginning of current function
+				// (when snapshot already exist on source and dest)
+				return
+			}
+			
+			StopJail([]string{cj.Name})
+			
+			fmt.Printf("Snapshot %s: ", dsconf)
+			if err = zfsSnapshot(dsconf, "gocage_mig_last_sync"); err != nil {
+				fmt.Printf("Error: %v\n", err)
+				return
+			}
+			fmt.Printf("Done\n")
+			fmt.Printf("Snapshot %s: ", dsdata)
+			if err := zfsSnapshot(dsdata, "gocage_mig_last_sync"); err != nil {
+				fmt.Printf("Error: %v\n", err)
+				return
+			}
+			fmt.Printf("Done\n")
+			
+			fmt.Printf("Synchronize jail config to %s: ", dsconfdest)
+			if err := zfsCopyIncremental(fmt.Sprintf("%s@gocage_mig_init", dsconf), 
+										fmt.Sprintf("%s@gocage_mig_last_sync", dsconf),  
+										 dsconfdest); err != nil {
+											 fmt.Printf("Error: %v\n", err)
+										 }
+										 fmt.Printf("Done\n")
+			fmt.Printf("Synchronize jail filesystem dataset to %s: ", dsdatadest)
+			if err := zfsCopyIncremental(fmt.Sprintf("%s@gocage_mig_init", dsdata), 
+										fmt.Sprintf("%s@gocage_mig_last_sync", dsdata),  
+										dsdatadest); err != nil {
+				fmt.Printf("Error: %v\n", err)
+			}
+			fmt.Printf("Done\n")
+			
+			// TODO : Start jail on new datastore (! Currently ListJails won't support the double with same name !)
+			
+			// TODO : zfs destroy destpool/jails/jail_name@gocage_mig_first_snap
+			// TODO : zfs destroy destpool/jails/jail_name/root@gocage_mig_first_snap
+			// TODO : zfs destroy -r srcpool/iocage/jails/$jail
+		}
 	}
 }
 
 // Clean snapshots from an aborted migration
-func CleanMigrateMess(args []string) {
+func CleanMigrateMess(args []string) error {
 	var jailNames []string
 
 	if len(args) > 0 {
@@ -117,7 +170,7 @@ func CleanMigrateMess(args []string) {
 		cj, err := getJailFromArray(jn, gJails)
 		if cj == nil {
 			fmt.Printf("Error getting jail %s: Not found\n", jn)
-			return
+			return errors.New(fmt.Sprintf("Error getting jail %s: Not found\n", jn))
 		}
 		
 		cmd := fmt.Sprintf("zfs destroy %s@gocage_mig_init", strings.Join([]string{cj.Zpool, "iocage", "jails", jn}, "/"))
@@ -125,7 +178,7 @@ func CleanMigrateMess(args []string) {
 		if err != nil {
 			if false == strings.HasSuffix(out, "could not find any snapshots to destroy; check snapshot names.\n") {
 				fmt.Printf("Error executing command %s: %v; command returned: %s\n", cmd, err, out)
-				return
+				return errors.New(fmt.Sprintf("Error executing command %s: %v; command returned: %s\n", cmd, err, out))
 			}
 		}
 		cmd = fmt.Sprintf("zfs destroy %s@gocage_mig_init", strings.Join([]string{cj.Zpool, "iocage", "jails", jn, "root"}, "/"))
@@ -133,8 +186,26 @@ func CleanMigrateMess(args []string) {
 		if err != nil {
 			if false == strings.HasSuffix(out, "could not find any snapshots to destroy; check snapshot names.\n") {
 				fmt.Printf("Error executing command %s: %v; command returned: %s\n", cmd, err, out)
-				return
+				return errors.New(fmt.Sprintf("Error executing command %s: %v; command returned: %s\n", cmd, err, out))
+			}
+		}
+		cmd = fmt.Sprintf("zfs destroy %s@gocage_mig_last_sync", strings.Join([]string{cj.Zpool, "iocage", "jails", jn}, "/"))
+		out, err = executeCommand(cmd)
+		if err != nil {
+			if false == strings.HasSuffix(out, "could not find any snapshots to destroy; check snapshot names.\n") {
+				fmt.Printf("Error executing command %s: %v; command returned: %s\n", cmd, err, out)
+				return errors.New(fmt.Sprintf("Error executing command %s: %v; command returned: %s\n", cmd, err, out))
+			}
+		}
+		cmd = fmt.Sprintf("zfs destroy %s@gocage_mig_last_sync", strings.Join([]string{cj.Zpool, "iocage", "jails", jn, "root"}, "/"))
+		out, err = executeCommand(cmd)
+		if err != nil {
+			if false == strings.HasSuffix(out, "could not find any snapshots to destroy; check snapshot names.\n") {
+				fmt.Printf("Error executing command %s: %v; command returned: %s\n", cmd, err, out)
+				return errors.New(fmt.Sprintf("Error executing command %s: %v; command returned: %s\n", cmd, err, out))
 			}
 		}
 	}
+
+	return nil
 }