zrepl/zfs/zfs.go

113 lines
2.1 KiB
Go

package zfs
import (
"bufio"
"bytes"
"errors"
"fmt"
"io"
"os/exec"
"strings"
)
func InitialSend(snapshot string) (io.Reader, error) {
return nil, nil
}
func IncrementalSend(from, to string) (io.Reader, error) {
return nil, nil
}
type DatasetPath []string
func (p DatasetPath) ToString() string {
return strings.Join(p, "/")
}
func (p DatasetPath) Empty() bool {
return len(p) == 0
}
var EmptyDatasetPath DatasetPath = []string{}
func NewDatasetPath(s string) (p DatasetPath, err error) {
if s == "" {
return EmptyDatasetPath, nil // the empty dataset path
}
const FORBIDDEN = "@#|\t "
if strings.ContainsAny(s, FORBIDDEN) { // TODO space may be a bit too restrictive...
return nil, errors.New(fmt.Sprintf("path '%s' contains forbidden characters (any of '%s')", s, FORBIDDEN))
}
return strings.Split(s, "/"), nil
}
func toDatasetPath(s string) DatasetPath {
p, err := NewDatasetPath(s)
if err != nil {
panic(err)
}
return p
}
type DatasetFilter func(path DatasetPath) bool
type ZFSError struct {
Stderr []byte
WaitErr error
}
func (e ZFSError) Error() string {
return fmt.Sprintf("zfs exited with error: %s", e.WaitErr.Error())
}
var ZFS_BINARY string = "zfs"
func ZFSList(properties []string, zfsArgs ...string) (res [][]string, err error) {
args := make([]string, 0, 4+len(zfsArgs))
args = append(args,
"list", "-H", "-p",
"-o", strings.Join(properties, ","))
args = append(args, zfsArgs...)
cmd := exec.Command(ZFS_BINARY, args...)
var stdout io.Reader
stderr := bytes.NewBuffer(make([]byte, 0, 1024))
cmd.Stderr = stderr
if stdout, err = cmd.StdoutPipe(); err != nil {
return
}
if err = cmd.Start(); err != nil {
return
}
s := bufio.NewScanner(stdout)
buf := make([]byte, 1024)
s.Buffer(buf, 0)
res = make([][]string, 0)
for s.Scan() {
fields := strings.SplitN(s.Text(), "\t", len(properties))
if len(fields) != len(properties) {
err = errors.New("unexpected output")
return
}
res = append(res, fields)
}
if waitErr := cmd.Wait(); waitErr != nil {
err := ZFSError{
Stderr: stderr.Bytes(),
WaitErr: waitErr,
}
return nil, err
}
return
}