@@ -20,25 +20,38 @@ import (

 	"github.com/docker/docker/registry"

 )

+// DockerCli represents the docker command line client.

+// Instances of the client can be returned from NewDockerCli.

 type DockerCli struct {

-	proto      string

-	addr       string

+	// proto holds the client protocol i.e. unix.

+	proto string

+	// addr holds the client address.

+	addr string

+	// configFile holds the configuration file (instance of registry.ConfigFile).

 	configFile *registry.ConfigFile

-	in         io.ReadCloser

-	out        io.Writer

-	err        io.Writer

-	keyFile    string

-	tlsConfig  *tls.Config

-	scheme     string

-	// inFd holds file descriptor of the client's STDIN, if it's a valid file

+	// in holds the input stream and closer (io.ReadCloser) for the client.

+	in io.ReadCloser

+	// out holds the output stream (io.Writer) for the client.

+	out io.Writer

+	// err holds the error stream (io.Writer) for the client.

+	err io.Writer

+	// keyFile holds the key file as a string.

+	keyFile string

+	// tlsConfig holds the TLS configuration for the client, and will

+	// set the scheme to https in NewDockerCli if present.

+	tlsConfig *tls.Config

+	// scheme holds the scheme of the client i.e. https.

+	scheme string

+	// inFd holds the file descriptor of the client's STDIN (if valid).

 	inFd uintptr

-	// outFd holds file descriptor of the client's STDOUT, if it's a valid file

+	// outFd holds file descriptor of the client's STDOUT (if valid).

 	outFd uintptr

-	// isTerminalIn describes if client's STDIN is a TTY

+	// isTerminalIn indicates whether the client's STDIN is a TTY

 	isTerminalIn bool

-	// isTerminalOut describes if client's STDOUT is a TTY

+	// isTerminalOut dindicates whether the client's STDOUT is a TTY

 	isTerminalOut bool

-	transport     *http.Transport

+	// transport holds the client transport instance.

+	transport *http.Transport

 }

 var funcMap = template.FuncMap{

@@ -125,6 +138,10 @@ func (cli *DockerCli) CheckTtyInput(attachStdin, ttyMode bool) error {

 	return nil

 }

+// NewDockerCli returns a DockerCli instance with IO output and error streams set by in, out and err.

+// The key file, protocol (i.e. unix) and address are passed in as strings, along with the tls.Config. If the tls.Config

+// is set the client scheme will be set to https.

+// The client will be given a 32-second timeout (see https://github.com/docker/docker/pull/8035).

 func NewDockerCli(in io.ReadCloser, out, err io.Writer, keyFile string, proto, addr string, tlsConfig *tls.Config) *DockerCli {

 	var (

 		inFd          uintptr

@@ -149,15 +166,15 @@ func NewDockerCli(in io.ReadCloser, out, err io.Writer, keyFile string, proto, a

 		err = out

 	}

-	// The transport is created here for reuse during the client session

+	// The transport is created here for reuse during the client session.

 	tr := &http.Transport{

 		TLSClientConfig: tlsConfig,

 	}

-	// Why 32? See issue 8035

+	// Why 32? See https://github.com/docker/docker/pull/8035.

 	timeout := 32 * time.Second

 	if proto == "unix" {

-		// no need in compressing for local communications

+		// No need for compression in local communications.

 		tr.DisableCompression = true

 		tr.Dial = func(_, _ string) (net.Conn, error) {

 			return net.DialTimeout(proto, addr, timeout)