func downloadManifest(artifact *ct.Artifact) error {
verifier, err := verify.NewVerifier(artifact.Hashes, artifact.Size)
if err != nil {
return err
}
res, err := hh.RetryClient.Get(artifact.URI)
if err != nil {
return err
}
defer res.Body.Close()
if res.StatusCode != http.StatusOK {
return fmt.Errorf("unexpected HTTP status: %s", res.Status)
}
r := verifier.Reader(res.Body)
data, err := ioutil.ReadAll(r)
if err != nil {
return err
}
if err := verifier.Verify(); err != nil {
return err
}
artifact.RawManifest = data
return nil
}
func (l *LibcontainerBackend) mountSquashfs(m *host.Mountspec) (string, error) {
// use the layerLoader to ensure only one caller downloads any
// given layer ID
path, err := l.layerLoader.Do(m.ID, func() (interface{}, error) {
if vol := l.VolManager.GetVolume(m.ID); vol != nil {
return vol.Location(), nil
}
if m.URL == "" {
return "", fmt.Errorf("error getting squashfs layer %s: missing URL", m.ID)
}
verifier, err := verify.NewVerifier(m.Hashes, m.Size)
if err != nil {
return "", fmt.Errorf("error getting squashfs layer %s: %s", m.ID, err)
}
u, err := url.Parse(m.URL)
if err != nil {
return "", err
}
var layer io.ReadCloser
switch u.Scheme {
case "file":
f, err := os.Open(u.Path)
if err != nil {
return "", fmt.Errorf("error getting squashfs layer %s: %s", m.URL, err)
}
layer = f
case "http", "https":
res, err := l.httpClient.Get(m.URL)
if err != nil {
return "", fmt.Errorf("error getting squashfs layer from %s: %s", m.URL, err)
}
if res.StatusCode != http.StatusOK {
return "", fmt.Errorf("error getting squashfs layer from %s: unexpected HTTP status %s", m.URL, res.Status)
}
layer = res.Body
default:
return "", fmt.Errorf("unknown layer URI scheme: %s", u.Scheme)
}
defer layer.Close()
// write the layer to a temp file and verify it has the
// expected hashes
tmp, err := ioutil.TempFile("", "flynn-layer-")
if err != nil {
return "", err
}
defer os.Remove(tmp.Name())
defer tmp.Close()
if _, err := io.Copy(tmp, verifier.Reader(layer)); err != nil {
return "", fmt.Errorf("error getting squashfs layer from %s: %s", m.URL, err)
}
if err := verifier.Verify(); err != nil {
return "", fmt.Errorf("error getting squashfs layer from %s: %s", m.URL, err)
}
if _, err := tmp.Seek(0, os.SEEK_SET); err != nil {
return "", fmt.Errorf("error seeking squashfs layer temp file: %s", err)
}
vol, err := l.VolManager.ImportFilesystem("default", &volume.Filesystem{
ID: m.ID,
Data: tmp,
Size: m.Size,
Type: volume.VolumeTypeSquashfs,
MountFlags: syscall.MS_RDONLY,
Meta: m.Meta,
})
if err != nil {
return "", fmt.Errorf("error importing squashfs layer: %s", err)
}
return vol.Location(), nil
})
if err != nil {
return "", err
}
return path.(string), nil
}