// updateTUFClient updates the given client, initializing and re-running the
// update if ErrNoRootKeys is returned.
func updateTUFClient(client *tuf.Client) error {
_, err := client.Update()
if err == nil || tuf.IsLatestSnapshot(err) {
return nil
}
if err == tuf.ErrNoRootKeys {
if err := client.Init(rootKeys, len(rootKeys)); err != nil {
return err
}
return updateTUFClient(client)
}
return err
}
func Download(client *tuf.Client, path string) (io.ReadCloser, error) {
tmp, err := NewTempFile()
if err != nil {
return nil, err
}
if err := client.Download(path, tmp); err != nil {
return nil, err
}
if _, err := tmp.Seek(0, os.SEEK_SET); err != nil {
return nil, err
}
return tmp, nil
}
// updateAndExecLatest updates the tuf DB, downloads the latest flynn-host
// binary to a temp file and execs it.
//
// Latest snapshot errors are ignored because, even though we may have the
// latest snapshot, the cluster may not be fully up to date (a previous update
// may have failed).
func updateAndExecLatest(configDir string, client *tuf.Client, log log15.Logger) error {
log.Info("updating TUF data")
if _, err := client.Update(); err != nil && !tuf.IsLatestSnapshot(err) {
log.Error("error updating TUF client", "err", err)
return err
}
version, err := getChannelVersion(configDir, client, log)
if err != nil {
return err
}
log.Info(fmt.Sprintf("downloading %s flynn-host binary", version))
gzTmp, err := tufutil.Download(client, path.Join(version, "flynn-host.gz"))
if err != nil {
log.Error("error downloading latest flynn-host binary", "err", err)
return err
}
defer gzTmp.Close()
gz, err := gzip.NewReader(gzTmp)
if err != nil {
log.Error("error creating gzip reader", "err", err)
return err
}
defer gz.Close()
tmp, err := ioutil.TempFile("", "flynn-host")
if err != nil {
log.Error("error creating temp file", "err", err)
return err
}
_, err = io.Copy(tmp, gz)
tmp.Close()
if err != nil {
log.Error("error decompressing gzipped flynn-host binary", "err", err)
return err
}
if err := os.Chmod(tmp.Name(), 0755); err != nil {
log.Error("error setting executable bit on tmp file", "err", err)
return err
}
log.Info("executing latest flynn-host binary")
argv := []string{tmp.Name()}
argv = append(argv, os.Args[1:]...)
argv = append(argv, "--is-latest")
argv = append(argv, "--is-tempfile")
return syscall.Exec(tmp.Name(), argv, os.Environ())
}
// GetVersion returns the given target's version from custom metadata
func GetVersion(client *tuf.Client, name string) (string, error) {
targets, err := client.Targets()
if err != nil {
return "", err
}
target, ok := targets[name]
if !ok {
return "", fmt.Errorf("missing %q in tuf targets", name)
}
if target.Custom == nil || len(*target.Custom) == 0 {
return "", errors.New("missing custom metadata in tuf target")
}
var data struct {
Version string
}
json.Unmarshal(*target.Custom, &data)
if data.Version == "" {
return "", errors.New("missing version in tuf target")
}
return data.Version, nil
}