func zpoolTest(t *testing.T, fn func()) {
tempfiles := make([]string, 3)
for i := range tempfiles {
f, _ := ioutil.TempFile("/tmp/", "zfs-")
defer f.Close()
err := f.Truncate(pow2(30))
ok(t, err)
tempfiles[i] = f.Name()
defer os.Remove(f.Name())
}
pool, err := zfs.CreateZpool("test", nil, tempfiles...)
ok(t, err)
defer pool.Destroy()
ok(t, err)
fn()
}
func NewProvider(config *ProviderConfig) (volume.Provider, error) {
if _, err := exec.LookPath("zfs"); err != nil {
return nil, fmt.Errorf("zfs command is not available")
}
dataset, err := zfs.GetDataset(config.DatasetName)
if err != nil {
if isDatasetNotExistsError(err) {
// if the dataset doesn't exist...
if config.Make == nil {
// not much we can do without a dataset or pool to contain data
return nil, err
}
// make a zpool backed by a sparse file. it's the most portable thing we can do.
if err := os.MkdirAll(filepath.Dir(config.Make.BackingFilename), 0755); err != nil {
return nil, err
}
f, err := os.OpenFile(config.Make.BackingFilename, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0600)
if err == nil {
// if we've created a new file, size it and create a new zpool
if err = f.Truncate(config.Make.Size); err != nil {
return nil, err
}
f.Close()
if _, err = zfs.CreateZpool(
config.DatasetName,
nil,
"-mnone", // do not mount the root dataset. (we'll mount our own datasets as necessary.)
config.Make.BackingFilename,
); err != nil {
return nil, err
}
} else if err.(*os.PathError).Err == syscall.EEXIST {
// if the file already exists, check it for existing zpool
if err := zpoolImportFile(config.Make.BackingFilename); err != nil {
// if 'zpool import' didn't believe it... halt here
// we could overwrite but we'd rather stop and avoid potential data loss.
return nil, fmt.Errorf("error attempting import of existing zpool file: %s", err)
}
// note: 'zpool import' recreated *all* the volume datasets in that pool.
// currently, even if they're not known to a volume manager, they're not garbage collected.
} else {
return nil, err
}
// get the dataset again... `zfs.Zpool` isn't a `zfs.Dataset`
dataset, err = zfs.GetDataset(config.DatasetName)
if err != nil {
return nil, err
}
} else {
// any error more complicated than not_exists, and we're out of our depth
return nil, err
}
}
if config.WorkingDir == "" {
config.WorkingDir = "/var/lib/flynn/volumes/zfs/"
}
return &Provider{
config: config,
dataset: dataset,
volumes: make(map[string]*zfsVolume),
}, nil
}