Check if dataset exist, create dataset

cmd/utils.go

@@ -4,7 +4,7 @@ import (
 	"io"
 	"os"
 	"fmt"
-	"log"
+	//"log"
 	"sort"
 	"bufio"
 	"errors"
@@ -15,6 +15,7 @@ import (
 	"io/ioutil"
 	"github.com/google/shlex"
 	"github.com/c2h5oh/datasize"
+	log "github.com/sirupsen/logrus"
 )
 
 const (
@@ -411,6 +412,31 @@ func zfsCopyIncremental(firstsnap string, secondsnap string, dest string) error
 	
 	return nil
 }
+
+// Return true if dataset exist, false if not, false & error if anything else
+func doZfsDatasetExist(dataset string) (bool, error) {
+	cmd := fmt.Sprintf("zfs list %s", dataset)
+	out, err := executeCommand(cmd)
+	if err != nil {
+		if strings.HasSuffix(strings.TrimSuffix(out, "\n"), "dataset does not exist") {
+			return false, nil
+		} else {
+			return false, errors.New(fmt.Sprintf("%v; command returned \"%s\"", err, out))
+		}
+	}
+	return true, nil
+}
+
+// Create ZFS dataset. mountpoint can be "none", then the dataset won't be mounted
+func createZfsDataset(dataset, mountpoint, compression string) error {
+	cmd := fmt.Sprintf("zfs create -o mountpoint=%s -o compression=%s %s", mountpoint, compression, dataset)
+	out, err := executeCommand(cmd)
+	if err != nil {
+		return errors.New(fmt.Sprintf("%v; command returned \"%s\"", err, out))
+	}
+	return nil
+}
+
 /*****************************************************************************
  *
  * rc.conf management