}

// IsDocker - returns if the environment minio is running in docker or
// not. The check is a simple file existence check.
//
// https://github.com/moby/moby/blob/master/daemon/initlayer/setup_unix.go
// https://github.com/containers/podman/blob/master/libpod/runtime.go
//
//	"/.dockerenv":        "file",
//	"/run/.containerenv": "file",
func IsDocker() bool {
	var err error

		Signature string
		Type      uint8
		Flags     uint8
		EcM, EcN  uint8 // Note that these will be 0/0 for non-v2 objects and older xl.meta
	}{
		VersionID: hex.EncodeToString(z.VersionID[:]),
		ModTime:   time.Unix(0, z.ModTime),
		Signature: hex.EncodeToString(z.Signature[:]),
		Type:      z.Type,
		Flags:     z.Flags,
		EcM:       z.EcM,
		EcN:       z.EcN,
	}
	return json.Marshal(tmp)
}

// Check if the given error corresponds to the ELOOP (too many symlinks).
func isSysErrTooManySymlinks(err error) bool {
	return errors.Is(err, syscall.ELOOP)
}

// Check if the given error corresponds to ENOTEMPTY for unix,
// EEXIST for solaris variants,
// and ERROR_DIR_NOT_EMPTY for windows (directory not empty).
func isSysErrNotEmpty(err error) bool {
	if errors.Is(err, syscall.ENOTEMPTY) {
		return true
	}

	listeners := make([]net.Listener, 0, len(serverAddrs))
	listenErrs = make([]error, len(serverAddrs))

	// Unix listener with special TCP options.
	listenCfg := net.ListenConfig{
		Control: setTCPParametersFn(opts),
	}

	for i, serverAddr := range serverAddrs {
		l, e := listenCfg.Listen(ctx, "tcp", serverAddr)

	req := mustNewRequest(method, urlStr, contentLength, body, t)
	cred := globalActiveCred
	if err := preSignV2(req, cred.AccessKey, cred.SecretKey, time.Now().Add(10*time.Minute).Unix()); err != nil {
		t.Fatalf("Unable to initialized new signed http request %s", err)
	}
	return req
}

// This is similar to mustNewRequest but additionally the request

xlHeaderVersion version == 1:

```
//msgp:tuple xlMetaV2VersionHeader
type xlMetaV2VersionHeader struct {
 VersionID [16]byte  // Version UUID, raw.
 ModTime   int64     // Unix nanoseconds.
 Signature [4]byte   // Signature of metadata.
 Type      uint8     // Type if the version
 Flags     uint8
}
```

The following flags are defined:

```
const (

		authtype = "REST-HEADER"
	case authTypePostPolicy:
		authtype = "POST"
	}

	args := map[string][]string{
		"CurrentTime":      {currTime.Format(time.RFC3339)},
		"EpochTime":        {strconv.FormatInt(currTime.Unix(), 10)},
		"SecureTransport":  {strconv.FormatBool(r.TLS != nil)},
		"SourceIp":         {handlers.GetSourceIPRaw(r)},
		"UserAgent":        {r.UserAgent()},
		"Referer":          {r.Referer()},

			{
				// Enable big buffers
				_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_SNDBUF, opts.SendBufSize)

				_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_RCVBUF, opts.RecvBufSize)
			}

			// Enable TCP open
			// https://lwn.net/Articles/508865/ - 32k queue size.
			_ = syscall.SetsockoptInt(fd, syscall.SOL_TCP, unix.TCP_FASTOPEN, 32*1024)

			// Enable TCP fast connect

```
ftp localhost -P 8021
Connected to localhost.
220 Welcome to MinIO FTP Server
Name (localhost:user): minioadmin
331 User name ok, password required
Password:
230 Password ok, continue
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> ls runner/
229 Entering Extended Passive Mode (|||39155|)
150 Opening ASCII mode data connection for file list
drwxrwxrwx 1 nobody nobody            0 Jan  1 00:00 chunkdocs/

	tmp := struct {
		VersionID string
		ModTime   time.Time
		Signature string
		Type      uint8
		Flags     uint8
	}{
		VersionID: hex.EncodeToString(z.VersionID[:]),
		ModTime:   time.Unix(0, z.ModTime),
		Signature: hex.EncodeToString(z.Signature[:]),
		Type:      z.Type,
		Flags:     z.Flags,
	}
	return json.Marshal(tmp)